netsurf/css/css.c

/*
 * Copyright 2004 James Bursa <bursa@users.sourceforge.net>
 * Copyright 2004 John M Bell <jmb202@ecs.soton.ac.uk>
 * Copyright 2008 Michael Drake <tlsa@netsurf-browser.org>
 *
 * This file is part of NetSurf, http://www.netsurf-browser.org/
 *
 * NetSurf is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation; version 2 of the License.
 *
 * NetSurf is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program.  If not, see <http://www.gnu.org/licenses/>.
 */

/** \file
 * CSS handling (implementation).
 *
 * See CSS 2.1 chapter 5 for the terms used here.
 *
 * CSS style sheets are stored as a hash table mapping selectors to styles.
 * Selectors are hashed by the <em>type selector</em> of the last <em>simple
 * selector</em> in the selector. The <em>universal selector</em> is hashed to
 * chain 0.
 *
 * A <em>simple selector</em> is a struct css_selector with type
 * CSS_SELECTOR_ELEMENT. The data field is the <em>type selector</em>, or 0 for
 * the <em>universal selector</em>. Any <em>attribute selectors</em>, <em>ID
 * selectors</em>, or <em>pseudo-classes</em> form a linked list of
 * css_selector hanging from detail.
 *
 * A <em>selector</em> is a linked list by the combiner field of these simple
 * selectors, in reverse order that they appear in the concrete syntax. The last
 * simple selector is first, then the previous one is linked at combiner and has
 * relationship comb to the last, etc.
 *
 * Selectors are then linked in each hash chain by next, in order of increasing
 * specificity.
 *
 * As an example, the stylesheet
 * \code
 *   th { [1] }
 *   div#id1 > h4.class1 { [2] }
 *   center * { [3] }                                                  \endcode
 *
 * would result in a struct css_stylesheet (content::data.css.css) like this
 * \dot
 *   digraph example {
 *     node [shape=record, fontname=Helvetica, fontsize=9];
 *     edge [fontname=Helvetica, fontsize=9];
 *     css -> n0 [label="rule[0]"];
 *     css -> n2 [label="rule[29]"];
 *
 *     n0 [label="css_selector\ntype CSS_SELECTOR_ELEMENT\ldata 0\lcomb CSS_COMB_ANCESTOR\lspecificity 2\l"];
 *     n0 -> n1 [label="combiner"];
 *     n0 -> n0style [label="style"]; n0style [label="[3]"];
 *
 *     n1 [label="css_selector\ntype CSS_SELECTOR_ELEMENT\ldata \"center\"\lcomb CSS_COMB_NONE\lspecificity 1\l"];
 *
 *     n2 [label="css_selector\ntype CSS_SELECTOR_ELEMENT\ldata \"th\"\lcomb CSS_COMB_NONE\lspecificity 1\l"];
 *     n2 -> n3 [label="next"];
 *     n2 -> n2style [label="style"]; n2style [label="[1]"];
 *
 *     n3 [label="css_selector\ntype CSS_SELECTOR_ELEMENT\ldata \"h4\"\lcomb CSS_COMB_PARENT\lspecificity 0x10102\l"];
 *     n3 -> n4 [label="detail"];
 *     n3 -> n5 [label="combiner"];
 *     n3 -> n3style [label="style"]; n3style [label="[2]"];
 *
 *     n4 [label="css_selector\ntype CSS_SELECTOR_CLASS\ldata \"class1\"\lcomb CSS_COMB_NONE\lspecificity 0x100\l"];
 *
 *     n5 [label="css_selector\ntype CSS_SELECTOR_ELEMENT\ldata \"div\"\lcomb CSS_COMB_NONE\lspecificity 0x10001\l"];
 *     n5 -> n6 [label="detail"];
 *
 *     n6 [label="css_selector\ntype CSS_SELECTOR_ID\ldata \"#id1\"\lcomb CSS_COMB_NONE\lspecificity 0x10000\l"];
 *   }
 * \enddot
 *
 * (any fields not shown are 0). In this example the first two rules happen to
 * have hashed to the same value.
 */

#define _GNU_SOURCE  /* for strndup */
#include <assert.h>
#include <stdint.h>
#include <stdlib.h>
#include <string.h>
#include <strings.h>
#include <math.h>
#include <limits.h>
#define CSS_INTERNALS
#undef NDEBUG
#include "utils/config.h"
#include "content/content.h"
#include "content/fetch.h"
#include "content/fetchcache.h"
#include "css/css.h"
#include "css/parser.h"
#include "desktop/gui.h"
#include "desktop/options.h"
#include "utils/log.h"
#include "utils/messages.h"
#include "utils/talloc.h"
#include "utils/url.h"
#include "utils/utils.h"

/* Define this to debug the working stylesheet */
#undef DEBUG_WORKING_STYLESHEET
struct css_working_stylesheet {
	struct css_selector **rule[HASH_SIZE];
};


static void css_deep_free_style(struct css_style *style);
static void css_atimport_callback(content_msg msg, struct content *css,
		intptr_t p1, intptr_t p2, union content_msg_data data);
static bool css_working_list_imports(struct content **import,
		unsigned int import_count,
		struct content ***css, unsigned int *css_count);
static bool css_working_merge_chains(
		struct css_working_stylesheet *working_stylesheet,
		struct content **css, unsigned int css_count,
		unsigned int chain,
		struct css_selector **rule);
static bool css_match_rule(struct css_selector *rule, xmlNode *element);
static bool css_match_detail(const struct css_selector *detail,
		xmlNode *element);
static bool css_match_first_child(const struct css_selector *detail,
		xmlNode *element);
static void css_dump_length(FILE *stream,
		const struct css_length * const length);
static void css_dump_selector(const struct css_selector *r);
#ifdef DEBUG_WORKING_STYLESHEET
static void css_dump_working_stylesheet(
		const struct css_working_stylesheet *ws);
#endif
static void css_importance_reset(struct css_importance *i);

/** Default style for a document. These are the 'Initial values' from the
 *  spec. */
const struct css_style css_base_style = {
	CSS_BACKGROUND_ATTACHMENT_SCROLL,
	0xffffff,
	{ CSS_BACKGROUND_IMAGE_NONE, 0 },
	{ { CSS_BACKGROUND_POSITION_PERCENT, { 0.0 } },
	  { CSS_BACKGROUND_POSITION_PERCENT, { 0.0 } } },
	CSS_BACKGROUND_REPEAT_REPEAT,
	{ { 0x000000, { CSS_BORDER_WIDTH_LENGTH,
	    { 2, CSS_UNIT_PX } }, CSS_BORDER_STYLE_NONE },
	  { 0x000000, { CSS_BORDER_WIDTH_LENGTH,
	    { 2, CSS_UNIT_PX } }, CSS_BORDER_STYLE_NONE },
	  { 0x000000, { CSS_BORDER_WIDTH_LENGTH,
	    { 2, CSS_UNIT_PX } }, CSS_BORDER_STYLE_NONE },
	  { 0x000000, { CSS_BORDER_WIDTH_LENGTH,
	    { 2, CSS_UNIT_PX } }, CSS_BORDER_STYLE_NONE } },
	CSS_BORDER_COLLAPSE_SEPARATE,
	{ CSS_BORDER_SPACING_LENGTH,
	  { 0, CSS_UNIT_PX }, { 0, CSS_UNIT_PX } },
	CSS_CAPTION_SIDE_TOP,
	CSS_CLEAR_NONE,
	{ CSS_CLIP_AUTO, { { CSS_CLIP_RECT_AUTO, { 0, CSS_UNIT_PX } },
	  { CSS_CLIP_RECT_AUTO, { 0, CSS_UNIT_PX } },
	  { CSS_CLIP_RECT_AUTO, { 0, CSS_UNIT_PX } },
	  { CSS_CLIP_RECT_AUTO, { 0, CSS_UNIT_PX } } } },
	0x000000,
	{ CSS_CONTENT_NORMAL, 0 },
	{ CSS_COUNTER_RESET_NONE, 0 },
	{ CSS_COUNTER_INCREMENT_NONE, 0 },
	CSS_CURSOR_AUTO,
	CSS_DIRECTION_LTR,
	CSS_DISPLAY_BLOCK,
	CSS_EMPTY_CELLS_SHOW,
	CSS_FLOAT_NONE,
	CSS_FONT_FAMILY_SANS_SERIF,
	{ CSS_FONT_SIZE_LENGTH, { { 10, CSS_UNIT_PT } } },
	CSS_FONT_STYLE_NORMAL,
	CSS_FONT_VARIANT_NORMAL,
	CSS_FONT_WEIGHT_NORMAL,
	{ CSS_HEIGHT_AUTO, { { 1, CSS_UNIT_EM } } },
	{ CSS_LETTER_SPACING_NORMAL, { 0, CSS_UNIT_PX } },
	{ CSS_LINE_HEIGHT_ABSOLUTE, { 1.33 } },
	{ CSS_LIST_STYLE_IMAGE_NONE, 0 },
	CSS_LIST_STYLE_POSITION_OUTSIDE,
	CSS_LIST_STYLE_TYPE_DISC,
	{ { CSS_MARGIN_LENGTH, { { 0, CSS_UNIT_PX } } },
	  { CSS_MARGIN_LENGTH, { { 0, CSS_UNIT_PX } } },
	  { CSS_MARGIN_LENGTH, { { 0, CSS_UNIT_PX } } },
	  { CSS_MARGIN_LENGTH, { { 0, CSS_UNIT_PX } } } },
	{ CSS_MAX_HEIGHT_NONE, { { 0, CSS_UNIT_PX } } },
	{ CSS_MAX_WIDTH_NONE, { { 0, CSS_UNIT_PX } } },
	{ CSS_MIN_HEIGHT_LENGTH, { { 0, CSS_UNIT_PX } } },
	{ CSS_MIN_WIDTH_LENGTH, { { 0, CSS_UNIT_PX } } },
	{ CSS_ORPHANS_INTEGER, 2 },
	{ { CSS_OUTLINE_COLOR_INVERT, 0x000000 },
	  { CSS_BORDER_WIDTH_LENGTH, { 2, CSS_UNIT_PX } },
	  CSS_BORDER_STYLE_NONE },
	CSS_OVERFLOW_VISIBLE,
	{ { CSS_PADDING_LENGTH, { { 0, CSS_UNIT_PX } } },
	  { CSS_PADDING_LENGTH, { { 0, CSS_UNIT_PX } } },
	  { CSS_PADDING_LENGTH, { { 0, CSS_UNIT_PX } } },
	  { CSS_PADDING_LENGTH, { { 0, CSS_UNIT_PX } } } },
	CSS_PAGE_BREAK_AFTER_AUTO,
	CSS_PAGE_BREAK_BEFORE_AUTO,
	CSS_PAGE_BREAK_INSIDE_AUTO,
	{ { CSS_POS_AUTO, { { 0, CSS_UNIT_PX } } },
	  { CSS_POS_AUTO, { { 0, CSS_UNIT_PX } } },
	  { CSS_POS_AUTO, { { 0, CSS_UNIT_PX } } },
	  { CSS_POS_AUTO, { { 0, CSS_UNIT_PX } } } },
	CSS_POSITION_STATIC,
	CSS_TABLE_LAYOUT_AUTO,
	CSS_TEXT_ALIGN_LEFT,
	CSS_TEXT_DECORATION_NONE,
	{ CSS_TEXT_INDENT_LENGTH, { { 0, CSS_UNIT_EM } } },
	CSS_TEXT_TRANSFORM_NONE,
	CSS_UNICODE_BIDI_NORMAL,
	{ CSS_VERTICAL_ALIGN_BASELINE, { { 0, CSS_UNIT_PX } } },
	CSS_VISIBILITY_VISIBLE,
	CSS_WHITE_SPACE_NORMAL,
	{ CSS_WIDOWS_INTEGER, 2 },
	{ CSS_WIDTH_AUTO, { { 1, CSS_UNIT_EM } } },
	{ CSS_WORD_SPACING_NORMAL, { 0, CSS_UNIT_PX } },
	{ CSS_Z_INDEX_AUTO, 0 }
};

/** Style with no values set. */
const struct css_style css_empty_style = {
	CSS_BACKGROUND_ATTACHMENT_NOT_SET,
	CSS_COLOR_NOT_SET,
	{ CSS_BACKGROUND_IMAGE_NOT_SET, 0 },
	{ { CSS_BACKGROUND_POSITION_NOT_SET, { 0.0 } },
	  { CSS_BACKGROUND_POSITION_NOT_SET, { 0.0 } } },
	CSS_BACKGROUND_REPEAT_NOT_SET,
	{ { CSS_COLOR_NOT_SET, { CSS_BORDER_WIDTH_NOT_SET,
	    { 0, CSS_UNIT_PX } }, CSS_BORDER_STYLE_NOT_SET },
	  { CSS_COLOR_NOT_SET, { CSS_BORDER_WIDTH_NOT_SET,
	    { 0, CSS_UNIT_PX } }, CSS_BORDER_STYLE_NOT_SET },
	  { CSS_COLOR_NOT_SET, { CSS_BORDER_WIDTH_NOT_SET,
	    { 0, CSS_UNIT_PX } }, CSS_BORDER_STYLE_NOT_SET },
	  { CSS_COLOR_NOT_SET, { CSS_BORDER_WIDTH_NOT_SET,
	    { 0, CSS_UNIT_PX } }, CSS_BORDER_STYLE_NOT_SET } },
	CSS_BORDER_COLLAPSE_NOT_SET,
	{ CSS_BORDER_SPACING_NOT_SET,
	  { 0, CSS_UNIT_PX }, { 0, CSS_UNIT_PX } },
	CSS_CAPTION_SIDE_NOT_SET,
	CSS_CLEAR_NOT_SET,
	{ CSS_CLIP_NOT_SET, { { CSS_CLIP_RECT_AUTO, { 0, CSS_UNIT_PX } },
	  { CSS_CLIP_RECT_AUTO, { 0, CSS_UNIT_PX } },
	  { CSS_CLIP_RECT_AUTO, { 0, CSS_UNIT_PX } },
	  { CSS_CLIP_RECT_AUTO, { 0, CSS_UNIT_PX } } } },
	CSS_COLOR_NOT_SET,
	{ CSS_CONTENT_NOT_SET, 0 },
	{ CSS_COUNTER_RESET_NOT_SET, 0 },
	{ CSS_COUNTER_INCREMENT_NOT_SET, 0 },
	CSS_CURSOR_NOT_SET,
	CSS_DIRECTION_NOT_SET,
	CSS_DISPLAY_NOT_SET,
	CSS_EMPTY_CELLS_NOT_SET,
	CSS_FLOAT_NOT_SET,
	CSS_FONT_FAMILY_NOT_SET,
	{ CSS_FONT_SIZE_NOT_SET, { { 1, CSS_UNIT_PT } } },
	CSS_FONT_STYLE_NOT_SET,
	CSS_FONT_VARIANT_NOT_SET,
	CSS_FONT_WEIGHT_NOT_SET,
	{ CSS_HEIGHT_NOT_SET, { { 1, CSS_UNIT_EM } } },
	{ CSS_LETTER_SPACING_NOT_SET, { 0, CSS_UNIT_PX } },
	{ CSS_LINE_HEIGHT_NOT_SET, { 1.33 } },
	{ CSS_LIST_STYLE_IMAGE_NOT_SET, 0 },
	CSS_LIST_STYLE_POSITION_NOT_SET,
	CSS_LIST_STYLE_TYPE_NOT_SET,
	{ { CSS_MARGIN_NOT_SET, { { 0, CSS_UNIT_PX } } },
	  { CSS_MARGIN_NOT_SET, { { 0, CSS_UNIT_PX } } },
	  { CSS_MARGIN_NOT_SET, { { 0, CSS_UNIT_PX } } },
	  { CSS_MARGIN_NOT_SET, { { 0, CSS_UNIT_PX } } } },
	{ CSS_MAX_HEIGHT_NOT_SET, { { 0, CSS_UNIT_PX } } },
	{ CSS_MAX_WIDTH_NOT_SET, { { 0, CSS_UNIT_PX } } },
	{ CSS_MIN_HEIGHT_NOT_SET, { { 0, CSS_UNIT_PX } } },
	{ CSS_MIN_WIDTH_NOT_SET, { { 0, CSS_UNIT_PX } } },
	{ CSS_ORPHANS_NOT_SET, 0 },
	{ { CSS_OUTLINE_COLOR_NOT_SET, CSS_COLOR_NOT_SET },
	  { CSS_BORDER_WIDTH_NOT_SET, { 0, CSS_UNIT_PX } },
	  CSS_BORDER_STYLE_NOT_SET },
	CSS_OVERFLOW_NOT_SET,
	{ { CSS_PADDING_NOT_SET, { { 0, CSS_UNIT_PX } } },
	  { CSS_PADDING_NOT_SET, { { 0, CSS_UNIT_PX } } },
	  { CSS_PADDING_NOT_SET, { { 0, CSS_UNIT_PX } } },
	  { CSS_PADDING_NOT_SET, { { 0, CSS_UNIT_PX } } } },
	CSS_PAGE_BREAK_AFTER_NOT_SET,
	CSS_PAGE_BREAK_BEFORE_NOT_SET,
	CSS_PAGE_BREAK_INSIDE_NOT_SET,
	{ { CSS_POS_NOT_SET, { { 0, CSS_UNIT_PX } } },
	  { CSS_POS_NOT_SET, { { 0, CSS_UNIT_PX } } },
	  { CSS_POS_NOT_SET, { { 0, CSS_UNIT_PX } } },
	  { CSS_POS_NOT_SET, { { 0, CSS_UNIT_PX } } } },
	CSS_POSITION_NOT_SET,
	CSS_TABLE_LAYOUT_NOT_SET,
	CSS_TEXT_ALIGN_NOT_SET,
	CSS_TEXT_DECORATION_NOT_SET,
	{ CSS_TEXT_INDENT_NOT_SET, { { 0, CSS_UNIT_EM } } },
	CSS_TEXT_TRANSFORM_NOT_SET,
	CSS_UNICODE_BIDI_NOT_SET,
	{ CSS_VERTICAL_ALIGN_NOT_SET, { { 0, CSS_UNIT_PX } } },
	CSS_VISIBILITY_NOT_SET,
	CSS_WHITE_SPACE_NOT_SET,
	{ CSS_WIDOWS_NOT_SET, 0 },
	{ CSS_WIDTH_NOT_SET, { { 1, CSS_UNIT_EM } } },
	{ CSS_WORD_SPACING_NOT_SET, { 0, CSS_UNIT_PX } },
	{ CSS_Z_INDEX_NOT_SET, 0 }
};

/** Default style for an element. These should be INHERIT if 'Inherited' is yes,
 *  and the 'Initial value' otherwise. */
const struct css_style css_blank_style = {
	CSS_BACKGROUND_ATTACHMENT_SCROLL,
	TRANSPARENT,
	{ CSS_BACKGROUND_IMAGE_NONE, 0 },
	{ { CSS_BACKGROUND_POSITION_PERCENT, { 0.0 } },
	  { CSS_BACKGROUND_POSITION_PERCENT, { 0.0 } } },
	CSS_BACKGROUND_REPEAT_REPEAT,
	{ { 0x000000, { CSS_BORDER_WIDTH_LENGTH,
	    { 2, CSS_UNIT_PX } }, CSS_BORDER_STYLE_NONE },
	  { 0x000000, { CSS_BORDER_WIDTH_LENGTH,
	    { 2, CSS_UNIT_PX } }, CSS_BORDER_STYLE_NONE },
	  { 0x000000, { CSS_BORDER_WIDTH_LENGTH,
	    { 2, CSS_UNIT_PX } }, CSS_BORDER_STYLE_NONE },
	  { 0x000000, { CSS_BORDER_WIDTH_LENGTH,
	    { 2, CSS_UNIT_PX } }, CSS_BORDER_STYLE_NONE } },
	CSS_BORDER_COLLAPSE_INHERIT,
	{ CSS_BORDER_SPACING_INHERIT,
	  { 0, CSS_UNIT_PX }, { 0, CSS_UNIT_PX } },
	CSS_CAPTION_SIDE_INHERIT,
	CSS_CLEAR_NONE,
	{ CSS_CLIP_AUTO, { { CSS_CLIP_RECT_AUTO, { 0, CSS_UNIT_PX } },
	  { CSS_CLIP_RECT_AUTO, { 0, CSS_UNIT_PX } },
	  { CSS_CLIP_RECT_AUTO, { 0, CSS_UNIT_PX } },
	  { CSS_CLIP_RECT_AUTO, { 0, CSS_UNIT_PX } } } },
	CSS_COLOR_INHERIT,
	{ CSS_CONTENT_NORMAL, 0 },
	{ CSS_COUNTER_RESET_NONE, 0 },
	{ CSS_COUNTER_INCREMENT_NONE, 0 },
	CSS_CURSOR_INHERIT,
	CSS_DIRECTION_INHERIT,
	CSS_DISPLAY_INLINE,
	CSS_EMPTY_CELLS_INHERIT,
	CSS_FLOAT_NONE,
	CSS_FONT_FAMILY_INHERIT,
	{ CSS_FONT_SIZE_INHERIT, { { 1, CSS_UNIT_EM } } },
	CSS_FONT_STYLE_INHERIT,
	CSS_FONT_VARIANT_INHERIT,
	CSS_FONT_WEIGHT_INHERIT,
	{ CSS_HEIGHT_AUTO, { { 1, CSS_UNIT_EM } } },
	{ CSS_LETTER_SPACING_INHERIT, { 0, CSS_UNIT_PX } },
	{ CSS_LINE_HEIGHT_INHERIT, { 1.33 } },
	{ CSS_LIST_STYLE_IMAGE_INHERIT, 0 },
	CSS_LIST_STYLE_POSITION_INHERIT,
	CSS_LIST_STYLE_TYPE_INHERIT,
	{ { CSS_MARGIN_LENGTH, { { 0, CSS_UNIT_PX } } },
	  { CSS_MARGIN_LENGTH, { { 0, CSS_UNIT_PX } } },
	  { CSS_MARGIN_LENGTH, { { 0, CSS_UNIT_PX } } },
	  { CSS_MARGIN_LENGTH, { { 0, CSS_UNIT_PX } } } },
	{ CSS_MAX_HEIGHT_NONE, { { 0, CSS_UNIT_PX } } },
	{ CSS_MAX_WIDTH_NONE, { { 0, CSS_UNIT_PX } } },
	{ CSS_MIN_HEIGHT_LENGTH, { { 0, CSS_UNIT_PX } } },
	{ CSS_MIN_WIDTH_LENGTH, { { 0, CSS_UNIT_PX } } },
	{ CSS_ORPHANS_INHERIT, 0 },
	{ { CSS_OUTLINE_COLOR_INVERT, 0x000000 },
	  { CSS_BORDER_WIDTH_LENGTH, { 2, CSS_UNIT_PX } },
	  CSS_BORDER_STYLE_NONE },
	CSS_OVERFLOW_VISIBLE,
	{ { CSS_PADDING_LENGTH, { { 0, CSS_UNIT_PX } } },
	  { CSS_PADDING_LENGTH, { { 0, CSS_UNIT_PX } } },
	  { CSS_PADDING_LENGTH, { { 0, CSS_UNIT_PX } } },
	  { CSS_PADDING_LENGTH, { { 0, CSS_UNIT_PX } } } },
	CSS_PAGE_BREAK_AFTER_AUTO,
	CSS_PAGE_BREAK_BEFORE_AUTO,
	CSS_PAGE_BREAK_INSIDE_INHERIT,
	{ { CSS_POS_AUTO, { { 0, CSS_UNIT_PX } } },
	  { CSS_POS_AUTO, { { 0, CSS_UNIT_PX } } },
	  { CSS_POS_AUTO, { { 0, CSS_UNIT_PX } } },
	  { CSS_POS_AUTO, { { 0, CSS_UNIT_PX } } } },
	CSS_POSITION_STATIC,
	CSS_TABLE_LAYOUT_AUTO,
	CSS_TEXT_ALIGN_INHERIT,
	CSS_TEXT_DECORATION_NONE,
	{ CSS_TEXT_INDENT_INHERIT, { { 0, CSS_UNIT_EM } } },
	CSS_TEXT_TRANSFORM_INHERIT,
	CSS_UNICODE_BIDI_NORMAL,
	{ CSS_VERTICAL_ALIGN_BASELINE, { { 0, CSS_UNIT_PX } } },
	CSS_VISIBILITY_INHERIT,
	CSS_WHITE_SPACE_INHERIT,
	{ CSS_WIDOWS_INHERIT, 0 },
	{ CSS_WIDTH_AUTO, { { 1, CSS_UNIT_EM } } },
	{ CSS_WORD_SPACING_INHERIT, { 0, CSS_UNIT_PX } },
	{ CSS_Z_INDEX_AUTO, 0 }
};

/** Dots per inch for the display device.
 *
 * This is the number of pixels per inch of the display device.
 * This variable should be treated as constant during the runtime of
 * the program unless the core can be persuaded to re-layout fully
 * on change.
 *
 * We default to 90.0 because RISC OS defaults to 90.0 dpi.
 */
float css_screen_dpi = 90.0;

/**
 * Convert a CONTENT_CSS for use.
 */

bool css_convert(struct content *c, int width, int height)
{
	unsigned char *source_data;
	unsigned char *current, *end, *token_text;
	unsigned int i;
	int token;
	void *parser;
	struct css_parser_params param = {false, c, 0, false, false, false};
	struct css_parser_token token_data;
	union content_msg_data msg_data;

	/* css_parser_Trace(stderr, "CSS: "); */

	c->data.css.css = malloc(sizeof *c->data.css.css);
	parser = css_parser_Alloc(malloc);
	source_data = (unsigned char *) talloc_realloc(c, c->source_data, char,
			c->source_size + 10);

	if (!c->data.css.css || !parser || !source_data) {
		free(c->data.css.css);
		css_parser_Free(parser, free);

		msg_data.error = messages_get("NoMemory");
		content_broadcast(c, CONTENT_MSG_ERROR, msg_data);
		return false;
	}

	for (i = 0; i != HASH_SIZE; i++)
		c->data.css.css->rule[i] = 0;
	c->data.css.import_count = 0;
	c->data.css.import_content = 0;
	c->data.css.origin = CSS_ORIGIN_UA;
	c->active = 0;
	c->source_data = (char *) source_data;

	for (i = 0; i != 10; i++)
		source_data[c->source_size + i] = 0;

	current = source_data;
	end = source_data + c->source_size;
	while (current < end
			&& (token = css_tokenise(&current, end + 10,
			&token_text))) {
		token_data.text = (char *) token_text;
		token_data.length = current - token_text;
		css_parser_(parser, token, token_data, &param);
		if (param.syntax_error) {
			LOG(("syntax error near offset %li (%s)",
				(unsigned long) (token_text - source_data),
				c->url));
			param.syntax_error = false;
		} else if (param.memory_error) {
			LOG(("out of memory"));
			break;
		}
	}

	css_parser_(parser, 0, token_data, &param);
	css_parser_Free(parser, free);

	if (param.memory_error) {
		msg_data.error = messages_get("NoMemory");
		content_broadcast(c, CONTENT_MSG_ERROR, msg_data);
		return false;
	}

	/*css_dump_stylesheet(c->data.css.css);*/

	/* complete fetch of any imported stylesheets */
	while (c->active != 0) {
		fetch_poll();
		gui_multitask();
	}

	c->status = CONTENT_STATUS_DONE;
	return true;
}


/**
 * Destroy a CONTENT_CSS and free all resources it owns.
 */

void css_destroy(struct content *c)
{
	unsigned int i;
	struct css_selector *r;

	if (c->data.css.css) {
		for (i = 0; i != HASH_SIZE; i++) {
			for (r = c->data.css.css->rule[i]; r != 0;
					r = r->next) {
				css_deep_free_style(r->style);
			}
			css_free_selector(c->data.css.css->rule[i]);
		}
		free(c->data.css.css);
	}

	/* imported stylesheets */
	for (i = 0; i != c->data.css.import_count; i++)
		if (c->data.css.import_content[i] != 0) {
			content_remove_user(c->data.css.import_content[i],
					css_atimport_callback, (intptr_t) c, i);
		}
	free(c->data.css.import_content);
}


/**
 * Set the origin of a stylesheet.
 *
 * \param  c       content of type CONTENT_CSS
 * \param  origin  new origin
 *
 * This may only be called once per stylesheet.
 */

void css_set_origin(struct content *c, css_origin origin)
{
	unsigned int chain, i;
	unsigned long specificity = 0;
	struct css_selector *selector;

	assert(c->type == CONTENT_CSS);

	if (origin == c->data.css.origin)
		return;

	switch (origin)
	{
	case CSS_ORIGIN_AUTHOR: specificity = CSS_SPECIFICITY_AUTHOR; break;
	case CSS_ORIGIN_USER:   specificity = CSS_SPECIFICITY_USER; break;
	case CSS_ORIGIN_UA:     specificity = CSS_SPECIFICITY_UA; break;
	}

	for (chain = 0; chain != HASH_SIZE; chain++)
		for (selector = c->data.css.css->rule[chain];
				selector;
				selector = selector->next)
			selector->specificity += specificity;
	c->data.css.origin = origin;

	for (i = 0; i != c->data.css.import_count; i++)
		if (c->data.css.import_content[i])
			css_set_origin(c->data.css.import_content[i], origin);
}


/**
 * Duplicate a CSS style struct.
 *
 * \param style The style to duplicate
 * \return The duplicate style, or NULL if out of memory.
 */

struct css_style *css_duplicate_style(const struct css_style * const style)
{
	struct css_style *dup;

	assert(style);

	/* create duplicated style */
	dup = malloc(sizeof (struct css_style));
	if (!dup)
		return NULL;

	/* copy all style information into duplicate style */
	memcpy(dup, style, sizeof(struct css_style));

	return dup;
}


/**
 * Free a CSS style.
 *
 * \param style The style to free
 */

void css_free_style(struct css_style *style)
{
	assert(style);

	free(style);
}


/**
 * Free a CSS style, deleting all alloced elements.
 *
 * \param style The style to free
 */

void css_deep_free_style(struct css_style *style)
{
	assert(style);

	if (style->background_image.type == CSS_BACKGROUND_IMAGE_URI)
		free(style->background_image.uri);

	if (style->list_style_image.type == CSS_LIST_STYLE_IMAGE_URI)
		free(style->list_style_image.uri);

	if (style->content.type == CSS_CONTENT_INTERPRET)
		css_deep_free_content(style->content.content);

	if (style->counter_reset.type == CSS_COUNTER_RESET_INTERPRET)
		css_deep_free_counter_control(style->counter_reset.data);

	if (style->counter_increment.type == CSS_COUNTER_INCREMENT_INTERPRET)
		css_deep_free_counter_control(style->counter_increment.data);

	free(style);
}


/**
 * Free all auto-generated content data.
 *
 * \param  content  the auto-generated content data to free
 */

void css_deep_free_content(struct css_content *content)
{
	struct css_content *next;

	while (content) {
		next = content->next;
		switch (content->type) {
			case CSS_CONTENT_STRING:
				free(content->data.string);
				break;
			case CSS_CONTENT_URI:
				free(content->data.uri);
				break;
			case CSS_CONTENT_COUNTER:
				free(content->data.counter.name);
				free(content->data.counter.separator);
				break;
			case CSS_CONTENT_ATTR:
				free(content->data.attr);
				break;
			case CSS_CONTENT_OPEN_QUOTE:
			case CSS_CONTENT_CLOSE_QUOTE:
			case CSS_CONTENT_NO_OPEN_QUOTE:
			case CSS_CONTENT_NO_CLOSE_QUOTE:
				break;
		}
		free(content);
		content = next;
	}
}


/**
 * Free all counter control data.
 *
 * \param counter  the counter control data to free
 */

void css_deep_free_counter_control(struct css_counter_control *control)
{
	struct css_counter_control *next;

	while (control) {
		next = control->next;
		free(control->name);
		free(control);
		control = next;
	}
}


/**
 * Create a new struct css_node.
 *
 * \param  stylesheet  content of type CONTENT_CSS
 * \param  type  type of node
 * \param  data  string for data, not copied
 * \param  data_length  length of data
 * \return  allocated node, or 0 if memory exhausted
 *
 * Used by the parser.
 */

struct css_node * css_new_node(struct content *stylesheet,
                css_node_type type,
		const char *data, unsigned int data_length)
{
	struct css_node *node = malloc(sizeof *node);
	if (!node)
		return 0;
	node->type = type;
	node->data = data;
	node->data_length = data_length;
	node->value = 0;
	node->next = 0;
	node->comb = CSS_COMB_NONE;
	node->style = 0;
	node->specificity = 0;
	node->stylesheet = stylesheet;

	return node;
}


/**
 * Free a struct css_node recursively.
 *
 * \param  node  css_node to free
 *
 * Used by the parser.
 */

void css_free_node(struct css_node *node)
{
	if (!node)
		return;
	if (node->value)
		css_free_node(node->value);
	if (node->next)
		css_free_node(node->next);
	free(node);
}


/**
 * Create a new struct css_selector.
 *
 * \param  type  type of selector
 * \param  data  string for data, not copied
 * \param  data_length  length of data
 * \return  allocated selector, or 0 if memory exhausted
 */

struct css_selector * css_new_selector(css_selector_type type,
		const char *data, unsigned int data_length)
{
	struct css_selector *node = malloc(sizeof *node);
	if (!node)
		return 0;
	node->type = type;
	node->data = data;
	node->data_length = data_length;
	node->data2 = 0;
	node->detail = 0;
	node->combiner = 0;
	node->next = 0;
	node->comb = CSS_COMB_NONE;
	node->style = 0;
	node->specificity = 0;
	return node;
}


/**
 * Free a struct css_selector recursively.
 *
 * \param  node  css_selector to free
 */

void css_free_selector(struct css_selector *node)
{
	if (!node)
		return;
	if (node->detail)
		css_free_selector(node->detail);
	if (node->combiner)
		css_free_selector(node->combiner);
	if (node->next)
		css_free_selector(node->next);
	free(node);
}


/**
 * Process an \@import rule.
 */

void css_atimport(struct content *c, struct css_node *node)
{
	const char *s;
	char *t, *url, *url1;
	bool string = false, screen = true;
	unsigned int i;
	struct content **import_content;
	url_func_result res;

	LOG(("@import rule"));

	import_content = realloc(c->data.css.import_content,
			(c->data.css.import_count + 1) *
			sizeof(*c->data.css.import_content));
	if (!import_content)  {
		/** \todo report to user */
		return;
	}
	c->data.css.import_content = import_content;

	/* uri(...) or "..." */
	switch (node->type) {
		case CSS_NODE_URI:
			LOG(("URI '%.*s'", node->data_length, node->data));
			for (s = node->data + 4;
					*s == ' ' || *s == '\t' || *s == '\r' ||
					*s == '\n' || *s == '\f';
					s++)
				;
			if (*s == '\'' || *s == '"') {
				string = true;
				s++;
			}
			url = strndup(s, node->data_length - (s - node->data));
			if (!url) {
				/** \todo report to user */
				return;
			}
			for (t = url + strlen(url) - 2;
					*t == ' ' || *t == '\t' || *t == '\r' ||
					*t == '\n' || *t == '\f';
					t--)
				;
			if (string)
				*t = 0;
			else
				*(t + 1) = 0;
			break;
		case CSS_NODE_STRING:
			LOG(("STRING '%.*s'", node->data_length, node->data));
			url = strndup(node->data, node->data_length);
			if (!url) {
				/** \todo report to user */
				return;
			}
			break;
		default:
			return;
	}

	/* media not specified, 'screen', or 'all' */
	for (node = node->next; node != 0; node = node->next) {
		screen = false;
		if (node->type != CSS_NODE_IDENT) {
			free(url);
			return;
		}
		LOG(("medium '%s'", node->data));
		if ((node->data_length == 6 &&
				strncmp(node->data, "screen", 6) == 0) ||
				(node->data_length == 3 &&
				strncmp(node->data, "all", 3) == 0)) {
			screen = true;
			break;
		}
		node = node->next;
		if (node == 0 || node->type != CSS_NODE_COMMA) {
			free(url);
			return;
		}
	}
	if (!screen) {
		free(url);
		return;
	}

	res = url_join(url, c->url, &url1);
	if (res != URL_FUNC_OK) {
		free(url);
		return;
	}

	/* start the fetch */
	c->data.css.import_count++;
	i = c->data.css.import_count - 1;
	c->data.css.import_content[i] = fetchcache(url1,
			css_atimport_callback, (intptr_t) c, i,
			c->width, c->height, true, 0, 0, false, false);
	if (c->data.css.import_content[i]) {
		c->active++;
		fetchcache_go(c->data.css.import_content[i], c->url,
				css_atimport_callback, (intptr_t) c, i,
				c->width, c->height,
				0, 0, false, c->url);
	}

	free(url);
}


/**
 * Fetchcache callback for imported stylesheets.
 */

void css_atimport_callback(content_msg msg, struct content *css,
		intptr_t p1, intptr_t p2, union content_msg_data data)
{
	struct content *c = (struct content *) p1;
	unsigned int i = p2;

	switch (msg) {
		case CONTENT_MSG_LOADING:
			if (css->type != CONTENT_CSS) {
				content_remove_user(css, css_atimport_callback,
						(intptr_t) c, i);
				if (!css->user_list->next) {
					/* We were only user and we don't
					 * want this content, so stop it
					 * fetching and mark it as having
					 * an error so it gets removed from
					 * the cache next time
					 * content_clean() gets called */
					fetch_abort(css->fetch);
					css->fetch = 0;
					css->status = CONTENT_STATUS_ERROR;
				}
				c->data.css.import_content[i] = 0;
				c->active--;
				content_add_error(c, "NotCSS", 0);
			}
			break;

		case CONTENT_MSG_READY:
			break;

		case CONTENT_MSG_DONE:
			LOG(("got imported stylesheet '%s'", css->url));
			/*css_dump_stylesheet(css->data.css);*/
			c->active--;
			break;
#ifdef WITH_AUTH
		case CONTENT_MSG_AUTH:
#endif
#ifdef WITH_SSL
		case CONTENT_MSG_SSL:
#endif
			/* todo: handle AUTH and SSL */

		case CONTENT_MSG_LAUNCH:
			/* Fall through */
		case CONTENT_MSG_ERROR:
			/* The stylesheet we were fetching may have been
			 * redirected, in that case, the object pointers
			 * will differ, so ensure that the object that's
			 * in error is still in use by us before invalidating
			 * the pointer */
			if (c->data.css.import_content[i] == css) {
				c->data.css.import_content[i] = 0;
				c->active--;
				content_add_error(c, "?", 0);
			}
			break;

		case CONTENT_MSG_STATUS:
			break;

		case CONTENT_MSG_NEWPTR:
			c->data.css.import_content[i] = css;
			break;

		default:
			assert(0);
	}
}


/**
 * Prepare a working stylesheet with pre-sorted lists of selectors from an
 * array of stylesheets.
 *
 * \param  stylesheet_content  array of contents of type CONTENT_CSS (each may
 *                             be 0)
 * \param  stylesheet_count    number of entries in css
 * \return  working stylesheet, or 0 on memory exhaustion
 *
 * See CSS 2.1 6.4.
 */

struct css_working_stylesheet *css_make_working_stylesheet(
		struct content **stylesheet_content,
		unsigned int stylesheet_count)
{
	struct content **css = 0;
	unsigned int css_count = 0;
	struct css_working_stylesheet *working_stylesheet;
	unsigned int chain;
	struct css_selector **rule_scratch;

	working_stylesheet = talloc(0, struct css_working_stylesheet);
	if (!working_stylesheet)
		return 0;

	/* make a complete list of stylesheets involved by walking @imports */
	css_working_list_imports(stylesheet_content, stylesheet_count,
			&css, &css_count);

	rule_scratch = talloc_array(working_stylesheet, struct css_selector *,
			css_count);
	if (!rule_scratch) {
		talloc_free(working_stylesheet);
		return 0;
	}

	/* merge the corresponding sorted hash chains from each stylesheet */
	for (chain = 0; chain != HASH_SIZE; chain++) {
		if (!css_working_merge_chains(working_stylesheet, css,
				css_count, chain, rule_scratch)) {
			talloc_free(working_stylesheet);
			return 0;
		}
	}

	talloc_free(rule_scratch);

#ifdef DEBUG_WORKING_STYLESHEET
	css_dump_working_stylesheet(working_stylesheet);
#endif

	return working_stylesheet;
}


/**
 * Recursively make a list of stylesheets and their imports.
 *
 * \param  import        array of contents of type CONTENT_CSS
 * \param  import_count  number of elements in import
 * \param  css           pointer to array of contents for result
 * \param  css_count     number of elements used so far in *css
 */

bool css_working_list_imports(struct content **import,
		unsigned int import_count,
		struct content ***css, unsigned int *css_count)
{
	unsigned int i, j;
	struct content **css2;
	for (i = 0; i != import_count; i++) {
		if (!import[i])
			continue;
		/* search for import[i] in css[0..css_count) */
		for (j = 0; j != *css_count && (*css)[j] != import[i]; j++)
			;
		if (j != *css_count)
			/* we've seen this stylesheet already */
			continue;
		/* recurse into imports of import[i] */
		if (!css_working_list_imports(import[i]->data.css.
				import_content,
				import[i]->data.css.import_count,
				css, css_count))
			return false;
		css2 = realloc(*css, sizeof *css * (*css_count + 1));
		if (!css2)
			return false;
		*css = css2;
		(*css)[*css_count] = import[i];
		(*css_count)++;
	}
	return true;
}


/**
 * Merge hash chains of rules into an array of pointers ordered by specificity.
 *
 * \param  working_stylesheet  working stylesheet to add array to
 * \param  css        array of contents of type CONTENT_CSS
 * \param  css_count  number of elements in css
 * \param  chain      hash chain index to merge
 * \param  rule       scratch array of css_selector with css_count entries
 * \return  true on success, false if memory exhausted
 */

bool css_working_merge_chains(struct css_working_stylesheet *working_stylesheet,
		struct content **css, unsigned int css_count,
		unsigned int chain,
		struct css_selector **rule)
{
	unsigned int sheet, rules, rules_done = 0;
	struct css_selector *selector;
	unsigned int best = 0;
	unsigned long min;

	/* count total rules */
	rules = 0;
	for (sheet = 0; sheet != css_count; sheet++)
		for (selector = css[sheet]->data.css.css->rule[chain];
				selector;
				selector = selector->next)
			rules++;
	working_stylesheet->rule[chain] = talloc_array(working_stylesheet,
			struct css_selector *, rules + 1);
	if (!working_stylesheet->rule[chain])
		return false;

	/* mergesort by specificity (increasing) */
	for (sheet = 0; sheet != css_count; sheet++) {
		rule[sheet] = 0;
		rule[sheet] = css[sheet]->data.css.css->rule[chain];
	}
	for (; rules_done != rules; rules_done++) {
		/* find rule with lowest specificity */
 		min = ULONG_MAX;
 		for (sheet = 0; sheet != css_count; sheet++) {
 			if (rule[sheet] && rule[sheet]->specificity < min) {
 				min = rule[sheet]->specificity;
 				best = sheet;
 			}
 		}
 		assert(min != ULONG_MAX);
 		working_stylesheet->rule[chain][rules_done] = rule[best];
 		rule[best] = rule[best]->next;
 	}
	assert(rules_done == rules);
	working_stylesheet->rule[chain][rules] = 0;

	return true;
}


/**
 * Find the style which applies to an element.
 *
 * \param  working_stylesheet  working stylesheet
 * \param  element  element in xml tree to match
 * \param  style    style to update
 * \pram   author   updated to indicate properties with author level css
 *                  importance
 *
 * The style is updated with any rules that match the element.
 */

void css_get_style(struct css_working_stylesheet *working_stylesheet,
		xmlNode *element, struct css_style *style,
		struct css_importance *author)
{
	unsigned int hash, rule_0 = 0, rule_h = 0;
	struct css_selector *rule;
	css_importance_reset(author); /* initialise to sub-author level */

	hash = css_hash((const char *) element->name,
			strlen((const char *) element->name));

	/* merge sort rules from special hash chain 0 (universal selector) and
	 * rules from hash chain for element name */
	while (working_stylesheet->rule[0] &&
			working_stylesheet->rule[0][rule_0] &&
			working_stylesheet->rule[hash] &&
			working_stylesheet->rule[hash][rule_h]) {
		if (working_stylesheet->rule[0][rule_0]->specificity <
				working_stylesheet->rule[hash][rule_h]->
				specificity) {
			rule = working_stylesheet->rule[0][rule_0];
			rule_0++;
                } else {
			rule = working_stylesheet->rule[hash][rule_h];
			rule_h++;
		}
		if (css_match_rule(rule, element))
			css_merge(style, rule->style, rule->specificity,
									author);
	}

	/* remaining rules from hash chain 0 */
	while (working_stylesheet->rule[0] &&
			working_stylesheet->rule[0][rule_0]) {
		rule = working_stylesheet->rule[0][rule_0];
		rule_0++;
		if (css_match_rule(rule, element))
			css_merge(style, rule->style, rule->specificity,
									author);
	}

	/* remaining rules from hash chain for element name */
	while (working_stylesheet->rule[hash] &&
			working_stylesheet->rule[hash][rule_h]) {
		rule = working_stylesheet->rule[hash][rule_h];
		rule_h++;
		if (css_match_rule(rule, element))
			css_merge(style, rule->style, rule->specificity,
									author);
	}
}


/**
 * Determine if a rule applies to an element.
 */

bool css_match_rule(struct css_selector *rule, xmlNode *element)
{
	struct css_selector *detail;
	xmlNode *anc, *prev;

	assert(element->type == XML_ELEMENT_NODE);

	if (rule->data && (rule->data_length !=
			strlen((const char *) element->name) ||
			strncasecmp(rule->data, (const char *) element->name,
				rule->data_length) != 0))
		return false;

	for (detail = rule->detail; detail; detail = detail->next) {
		if (!css_match_detail(detail, element))
			return false;
	}

	if (!rule->combiner)
		return true;

	switch (rule->comb) {
		case CSS_COMB_ANCESTOR:
			for (anc = element->parent; anc; anc = anc->parent)
				if (anc->type == XML_ELEMENT_NODE &&
						css_match_rule(rule->combiner, anc))
					return true;
			break;

		case CSS_COMB_PRECEDED:
			for (prev = element->prev;
					prev && prev->type != XML_ELEMENT_NODE;
					prev = prev->prev)
				;
			if (!prev)
				return false;
			return css_match_rule(rule->combiner, prev);
			break;

		case CSS_COMB_PARENT:
			for (anc = element->parent;
					anc && anc->type != XML_ELEMENT_NODE;
					anc = anc->parent)
				;
			if (!anc)
				return false;
			return css_match_rule(rule->combiner, anc);
			break;

		default:
			assert(0);
	}

	return false;
}


/**
 * Determine if a selector detail matches an element.
 *
 * \param  detail   a css_selector of type other than CSS_SELECTOR_ELEMENT
 * \param  element  element in xml tree to match
 * \return  true if the selector matches the element
 */

bool css_match_detail(const struct css_selector *detail,
		xmlNode *element)
{
	bool match = false;
	char *s = 0;
	char *space, *word;
	size_t length;

	switch (detail->type) {
		case CSS_SELECTOR_ID:
			s = (char *) xmlGetProp(element,
					(const xmlChar *) "id");
			/* case sensitive, according to HTML4.01 */
			if (s && strlen(s) == detail->data_length &&
					strncmp(detail->data, s,
					detail->data_length) == 0)
				match = true;
			break;

		case CSS_SELECTOR_CLASS:
			s = (char *) xmlGetProp(element,
					(const xmlChar *) "class");
			if (!s)
				break;
			word = s;
			do {
				space = strchr(word, ' ');
				if (space)
					length = space - word;
				else
					length = strlen(word);
				/* case sensitive, according to HTML4.01 */
				if (length == detail->data_length &&
						strncmp(word, detail->data,
						length) == 0) {
					match = true;
					break;
				}
				word = space + 1;
			} while (space);
			break;

		case CSS_SELECTOR_ATTRIB:
			/* matches if an attribute is present */
			word = strndup(detail->data, detail->data_length);
			if (!word) {
				/** \todo report to user */
				return false;
			}
			s = (char *) xmlGetProp(element,
					(const xmlChar *) word);
			free(word);
			if (s)
				match = true;
			break;

		case CSS_SELECTOR_ATTRIB_EQ:
			/* matches if an attribute has a certain value*/
			word = strndup(detail->data, detail->data_length);
			if (!word) {
				/** \todo report to user */
				return false;
			}
			s = (char *) xmlGetProp(element,
					(const xmlChar *) word);
			free(word);
			if (s && strlen(s) == detail->data2_length &&
					strncasecmp(detail->data2, s,
					detail->data2_length) == 0)
				match = true;
			break;

		case CSS_SELECTOR_ATTRIB_INC:
			/* matches if one of the space separated words
			 * in the attribute is equal */
			word = strndup(detail->data,
					detail->data_length);
			if (!word) {
				/** \todo report to user */
				return false;
			}
			s = (char *) xmlGetProp(element,
					(const xmlChar *) word);
			free(word);
			if (!s)
				break;
			word = s;
			do {
				space = strchr(word, ' ');
				if (space)
					length = space - word;
				else
					length = strlen(word);
				if (length == detail->data2_length &&
						strncasecmp(word, detail->data2,
						length) == 0) {
					match = true;
					break;
				}
				word = space + 1;
			} while (space);
			break;

		case CSS_SELECTOR_ATTRIB_DM:
			/* matches if a prefix up to a hyphen matches */
			word = strndup(detail->data,
					detail->data_length);
			if (!word) {
				/** \todo report to user */
				return false;
			}
			s = (char *) xmlGetProp(element,
					(const xmlChar *) word);
			free(word);
			if (!s)
				break;
			length = detail->data2_length;
			if (strncasecmp(detail->data2, s, length) == 0 &&
					(s[length] == '-' || s[length] == 0))
				match = true;
			break;

		case CSS_SELECTOR_ATTRIB_PRE:
			/* matches if the attribute begins with a certain
			 * value (CSS3) */
			word = strndup(detail->data, detail->data_length);
			if (!word) {
				/** \todo report to user */
				return false;
			}
			s = (char *)xmlGetProp(element,
					(const xmlChar *) word);
			free(word);
			if (s && strncasecmp(detail->data2, s,
					detail->data2_length) == 0)
				match = true;
			break;

		case CSS_SELECTOR_ATTRIB_SUF:
			/* matches if the attribute ends with a certain
			 * value (CSS3) */
			word = strndup(detail->data, detail->data_length);
			if (!word) {
				/** \todo report to user */
				return false;
			}
			s = (char *)xmlGetProp(element,
					(const xmlChar *) word);
			free(word);
			if (!s)
				break;
			length = strlen(s);
			if (detail->data2_length <= length) {
				word = s + (length - detail->data2_length);
				if (s && strncasecmp(detail->data2, word,
						detail->data2_length) == 0)
					match = true;
			}
			break;

		case CSS_SELECTOR_ATTRIB_SUB:
			/* matches if the attribute contains a certain
			 * value (CSS3) */
			word = strndup(detail->data, detail->data_length);
			if (!word) {
				/** \todo report to user */
				return false;
			}
			s = (char *)xmlGetProp(element,
					(const xmlChar *) word);
			free(word);
			if (!s)
				break;
			/* case insensitive strstr follows */
			/* space -> last possible start position */
			/* word -> start of string to search */
			space = s + (strlen(s) - detail->data2_length);
			word = s;
			while (word <= space) {
				if (strncasecmp(detail->data2, word,
						detail->data2_length) == 0) {
					match = true;
					break;
				}
				word++;
			}
			break;

		case CSS_SELECTOR_PSEUDO:
			if (detail->data_length == 11 &&
				strncasecmp(detail->data,
						"first-child", 11) == 0) {
				match = css_match_first_child(detail,
								element);
			}
			break;

		default:
			assert(0);
	}

	if (s)
		xmlFree(s);

	return match;
}


/**
 * Handle :first-child pseudo-class.
 *
 * \param  detail   a css_selector of type other than CSS_SELECTOR_ELEMENT
 * \param  element  element in xml tree to match
 * \return  true if the selector matches the element
 */

bool css_match_first_child(const struct css_selector *detail,
		xmlNode *element)
{
	xmlNode *prev;

	for (prev = element->prev; prev && prev->type != XML_ELEMENT_NODE;
						prev = prev->prev)
		;

	if (!prev)
		return true;

	return false;
}


/**
 * Parse a stand-alone CSS property list.
 *
 * \param  c      parent content
 * \param  style  css_style to update
 * \param  str    property list, as found in HTML style attributes
 */

void css_parse_property_list(struct content *c, struct css_style * style,
                            char * str)
{
	unsigned char *source_data;
	unsigned char *current, *end, *token_text;
	size_t length;
	unsigned int i;
	int token;
	void *parser;
	struct css_parser_params param = {true, c, 0, false, false, false};
	struct css_parser_token token_data;
	const struct css_parser_token token_start = { "{", 1 };
	const struct css_parser_token token_end = { "}", 1 };

	length = strlen(str);

	parser = css_parser_Alloc(malloc);
	source_data = malloc(length + 10);

	if (!parser || !source_data) {
		free(parser);
		css_parser_Free(parser, free);
		return;
	}

	strcpy((char *) source_data, str);
	for (i = 0; i != 10; i++)
		source_data[length + i] = 0;

	css_parser_(parser, LBRACE, token_start, &param);

	current = source_data;
	end = source_data + strlen(str);
	while (current < end
			&& (token = css_tokenise(&current, end + 10,
			&token_text))) {
		token_data.text = (char *) token_text;
		token_data.length = current - token_text;
		css_parser_(parser, token, token_data, &param);
		if (param.syntax_error) {
			LOG(("syntax error near offset %li",
				(unsigned long) (token_text - source_data)));
			param.syntax_error = false;
		} else if (param.memory_error) {
			LOG(("out of memory"));
			break;
		}
	}
	css_parser_(parser, RBRACE, token_end, &param);
	css_parser_(parser, 0, token_data, &param);

	css_parser_Free(parser, free);

	if (param.memory_error) {
		css_free_node(param.declaration);
		return;
	}

	css_add_declarations(style, param.declaration);

	css_free_node(param.declaration);

	free(source_data);
}


/**
 * Dump a css_style to stderr in CSS-like syntax.
 */

void css_dump_style(FILE *stream, const struct css_style * const style)
{
	unsigned int i;
	fprintf(stream, "{ ");

#define DUMP_COLOR(z, s) \
	if (style->z != CSS_COLOR_NOT_SET) {				\
		if (style->z == TRANSPARENT)				\
			fprintf(stream, s ": transparent; ");		\
		else if (style->z == CSS_COLOR_NONE)			\
			fprintf(stream, s ": none; ");			\
		else							\
			fprintf(stream, s ": #%.6x; ", style->z);	\
	}

#define DUMP_KEYWORD(z, s, n) \
	if (style->z != css_empty_style.z)				\
		fprintf(stream, s ": %s; ", n[style->z]);

	DUMP_COLOR(background_color, "background-color");
	if (style->background_attachment !=
			css_empty_style.background_attachment ||
			style->background_image.type !=
			css_empty_style.background_image.type ||
			style->background_position.horz.pos !=
			css_empty_style.background_position.horz.pos ||
			style->background_position.vert.pos !=
			css_empty_style.background_position.vert.pos ||
			style->background_repeat !=
			css_empty_style.background_repeat) {
		fprintf(stream, "background:");
		switch (style->background_image.type) {
		case CSS_BACKGROUND_IMAGE_NONE:
			fprintf(stream, " none");
			break;
		case CSS_BACKGROUND_IMAGE_INHERIT:
			fprintf(stream, " inherit");
			break;
		case CSS_BACKGROUND_IMAGE_URI:
			fprintf(stream, " (%p) \"%s\"",
					style->background_image.uri,
					style->background_image.uri);
			break;
		case CSS_BACKGROUND_IMAGE_NOT_SET:
			;
			break;
		default:
			fprintf(stream, " UNKNOWN");
			break;
		}

		if (style->background_repeat ==
				CSS_BACKGROUND_REPEAT_UNKNOWN)
			fprintf(stream, " UNKNOWN");
		else if (style->background_repeat ==
				CSS_BACKGROUND_REPEAT_NOT_SET)
			;
		else
			fprintf(stream, " %s",
				css_background_repeat_name[
						style->background_repeat]);

		if (style->background_attachment ==
				CSS_BACKGROUND_ATTACHMENT_UNKNOWN)
			fprintf(stream, " UNKNOWN");
		else if (style->background_attachment == CSS_BACKGROUND_ATTACHMENT_NOT_SET)
			;
		else
			fprintf(stream, " %s",
				css_background_attachment_name[
					style->background_attachment]);

		switch (style->background_position.horz.pos) {
		case CSS_BACKGROUND_POSITION_LENGTH:
			fprintf(stream, " ");
			css_dump_length(stream, &style->background_position.
					horz.value.length);
			break;
		case CSS_BACKGROUND_POSITION_PERCENT:
			fprintf(stream, " %g%%",
					style->background_position.
					horz.value.percent);
			break;
		case CSS_BACKGROUND_POSITION_INHERIT:
			fprintf(stream, " inherit");
			break;
		case CSS_BACKGROUND_POSITION_NOT_SET:
			break;
		default:
			fprintf(stream, " UNKNOWN");
			break;
		}
		switch (style->background_position.vert.pos) {
		case CSS_BACKGROUND_POSITION_LENGTH:
			fprintf(stream, " ");
			css_dump_length(stream, &style->background_position.
					vert.value.length);
			break;
		case CSS_BACKGROUND_POSITION_PERCENT:
			fprintf(stream, " %g%%",
					style->background_position.
					vert.value.percent);
			break;
		case CSS_BACKGROUND_POSITION_INHERIT:
			fprintf(stream, " inherit");
			break;
		case CSS_BACKGROUND_POSITION_NOT_SET:
			break;
		default:
			fprintf(stream, " UNKNOWN");
			break;
		}
		fprintf(stream, "; ");
	}
	for (i = 0; i != 4; i++) {
		if (style->border[i].color != CSS_COLOR_NOT_SET ||
				style->border[i].width.width !=
				CSS_BORDER_WIDTH_NOT_SET ||
				style->border[i].style !=
				CSS_BORDER_STYLE_NOT_SET) {
			fprintf(stream, "border-");
			switch (i) {
			case TOP:
				fprintf(stream, "top:");
				break;
			case RIGHT:
				fprintf(stream, "right:");
				break;
			case BOTTOM:
				fprintf(stream, "bottom:");
				break;
			case LEFT:
				fprintf(stream, "left:");
				break;
			}
			switch (style->border[i].width.width) {
			case CSS_BORDER_WIDTH_INHERIT:
				fprintf(stream, " inherit");
				break;
			case CSS_BORDER_WIDTH_LENGTH:
				fprintf(stream, " ");
				css_dump_length(stream,
						&style->border[i].width.value);
				break;
			case CSS_BORDER_WIDTH_NOT_SET:
				break;
			default:
				fprintf(stream, " UNKNOWN");
				break;
			}

			if (style->border[i].style ==
					CSS_BORDER_STYLE_UNKNOWN)
				fprintf(stream, " UNKNOWN");
			else if (style->border[i].style ==
					CSS_BORDER_STYLE_NOT_SET)
				;
			else
				fprintf(stream, " %s",
					css_border_style_name[
						style->border[i].style]);

			if (style->border[i].color == TRANSPARENT)
				fprintf(stream, " transparent");
			else if (style->border[i].color == CSS_COLOR_NONE)
				fprintf(stream, " none");
			else if (style->border[i].color == CSS_COLOR_INHERIT)
				fprintf(stream, " inherit");
			else if (style->border[i].color == CSS_COLOR_NOT_SET)
				;
			else
				fprintf(stream, " #%.6x",
						style->border[i].color);
			fprintf(stream, "; ");
		}
	}
	DUMP_KEYWORD(border_collapse, "border-collapse",
			css_border_collapse_name);
	if (style->border_spacing.border_spacing !=
			CSS_BORDER_SPACING_NOT_SET) {
		fprintf(stream, "border-spacing: ");
		css_dump_length(stream, &style->border_spacing.horz);
		fprintf(stream, " ");
		css_dump_length(stream, &style->border_spacing.vert);
		fprintf(stream, "; ");
	}

	DUMP_KEYWORD(caption_side, "caption-side", css_caption_side_name);
	DUMP_KEYWORD(clear, "clear", css_clear_name);

	if (style->clip.clip != CSS_CLIP_NOT_SET) {
		fprintf(stream, "clip: ");
		switch (style->clip.clip) {
		case CSS_CLIP_INHERIT:
			fprintf(stream, "inherit");
			break;
		case CSS_CLIP_AUTO:
			fprintf(stream, "auto");
			break;
		case CSS_CLIP_RECT:
			fprintf(stream, "rect(");
			for (i = 0; i != 4; i++) {
				switch (style->clip.rect[i].rect) {
				case CSS_CLIP_RECT_AUTO:
					fprintf(stream, "auto");
					break;
				case CSS_CLIP_RECT_LENGTH:
					css_dump_length(stream,
						&style->clip.rect[i].value);
					break;
				}
				if (i != 3)
					fprintf(stream, ", ");
			}
			fprintf(stream, ")");
			break;
		default:
			fprintf(stream, "UNKNOWN");
			break;
		}
		fprintf(stream, "; ");
	}
	DUMP_COLOR(color, "color");
	DUMP_KEYWORD(cursor, "cursor", css_cursor_name);
	DUMP_KEYWORD(direction, "direction", css_direction_name);
	DUMP_KEYWORD(display, "display", css_display_name);
	DUMP_KEYWORD(empty_cells, "empty-cells", css_empty_cells_name);
	DUMP_KEYWORD(float_, "float", css_float_name);

	if (style->font_style != CSS_FONT_STYLE_NOT_SET ||
			style->font_weight != CSS_FONT_WEIGHT_NOT_SET ||
			style->font_size.size != CSS_FONT_SIZE_NOT_SET ||
			style->line_height.size != CSS_LINE_HEIGHT_NOT_SET ||
			style->font_family != CSS_FONT_FAMILY_NOT_SET ||
			style->font_variant != CSS_FONT_VARIANT_NOT_SET) {
		fprintf(stream, "font:");

		if (style->font_style == CSS_FONT_STYLE_UNKNOWN)
			fprintf(stream, " UNKNOWN");
		else if (style->font_style == CSS_FONT_STYLE_NOT_SET)
			;
		else
			fprintf(stream, " %s",
				css_font_style_name[style->font_style]);

		if (style->font_weight == CSS_FONT_WEIGHT_UNKNOWN)
			fprintf(stream, " UNKNOWN");
		else if (style->font_weight == CSS_FONT_WEIGHT_NOT_SET)
			;
		else
			fprintf(stream, " %s",
				css_font_weight_name[style->font_weight]);

		switch (style->font_size.size) {
		case CSS_FONT_SIZE_ABSOLUTE:
			fprintf(stream, " [%g]",
				style->font_size.value.absolute);
			break;
		case CSS_FONT_SIZE_LENGTH:
			fprintf(stream, " ");
			css_dump_length(stream, &style->font_size.value.length);
			break;
		case CSS_FONT_SIZE_PERCENT:
			fprintf(stream, " %g%%",
				style->font_size.value.percent);
			break;
		case CSS_FONT_SIZE_INHERIT:
			fprintf(stream, " inherit");
			break;
		case CSS_FONT_SIZE_NOT_SET:
			break;
		default:
			fprintf(stream, " UNKNOWN");
			break;
		}
		switch (style->line_height.size) {
		case CSS_LINE_HEIGHT_ABSOLUTE:
			fprintf(stream, "/[%g]",
				style->line_height.value.absolute);
				break;
		case CSS_LINE_HEIGHT_LENGTH:
			fprintf(stream, "/");
			css_dump_length(stream,
					&style->line_height.value.length);
			break;
		case CSS_LINE_HEIGHT_PERCENT:
			fprintf(stream, "/%g%%",
				style->line_height.value.percent);
				break;
		case CSS_LINE_HEIGHT_INHERIT:
			fprintf(stream, "/inherit");
			break;
		case CSS_LINE_HEIGHT_NOT_SET:
			break;
		default:
			fprintf(stream, "/UNKNOWN");
			break;
		}
		if (style->font_family == CSS_FONT_FAMILY_UNKNOWN)
			fprintf(stream, " UNKNOWN");
		else if (style->font_family == CSS_FONT_FAMILY_NOT_SET)
			;
		else
			fprintf(stream, " %s",
				css_font_family_name[style->font_family]);

		if (style->font_variant == CSS_FONT_VARIANT_UNKNOWN)
			fprintf(stream, " UNKNOWN");
		else if (style->font_variant == CSS_FONT_VARIANT_NOT_SET)
			;
		else
			fprintf(stream, " %s",
				css_font_variant_name[style->font_variant]);
		fprintf(stream, "; ");
	}

	if (style->height.height != CSS_HEIGHT_NOT_SET) {
		fprintf(stream, "height: ");
		switch (style->height.height) {
		case CSS_HEIGHT_INHERIT:
			fprintf(stream, "inherit");
			break;
		case CSS_HEIGHT_AUTO:
			fprintf(stream, "auto");
			break;
		case CSS_HEIGHT_LENGTH:
			css_dump_length(stream, &style->height.value.length);
			break;
		case CSS_HEIGHT_PERCENT:
			fprintf(stream, "%g%%",
				style->height.value.percent);
			break;
		default:
			fprintf(stream, "UNKNOWN");
			break;
		}
		fprintf(stream, "; ");
	}

	if (style->letter_spacing.letter_spacing !=
			CSS_LETTER_SPACING_NOT_SET) {
		fprintf(stream, "letter-spacing: ");
		switch (style->letter_spacing.letter_spacing) {
		case CSS_LETTER_SPACING_INHERIT:
			fprintf(stream, "inherit");
			break;
		case CSS_LETTER_SPACING_NORMAL:
			fprintf(stream, "normal");
			break;
		case CSS_LETTER_SPACING_LENGTH:
			css_dump_length(stream, &style->letter_spacing.length);
			break;
		default:
			fprintf(stream, "UNKNOWN");
			break;
		}
		fprintf(stream, "; ");
	}

	if (style->list_style_type != CSS_LIST_STYLE_TYPE_NOT_SET ||
			style->list_style_position !=
			CSS_LIST_STYLE_POSITION_NOT_SET ||
			style->list_style_image.type !=
			CSS_LIST_STYLE_IMAGE_NOT_SET) {
		fprintf(stream, "list-style:");

		if (style->list_style_type == CSS_LIST_STYLE_TYPE_UNKNOWN)
			fprintf(stream, " UNKNOWN");
		else if (style->list_style_type == CSS_LIST_STYLE_TYPE_NOT_SET)
			;
		else
			fprintf(stream, " %s",
					css_list_style_type_name[
						style->list_style_type]);

		if (style->list_style_position ==
				CSS_LIST_STYLE_POSITION_UNKNOWN)
			fprintf(stream, " UNKNOWN");
		else if (style->list_style_position ==
				CSS_LIST_STYLE_POSITION_NOT_SET)
			;
		else
			fprintf(stream, " %s",
					css_list_style_position_name[
						style->list_style_position]);

		switch (style->list_style_image.type) {
		case CSS_LIST_STYLE_IMAGE_INHERIT:
			fprintf(stream, " inherit");
			break;
		case CSS_LIST_STYLE_IMAGE_NONE:
			fprintf(stream, " none");
			break;
		case CSS_LIST_STYLE_IMAGE_URI:
			fprintf(stream, " url('%s')",
				style->list_style_image.uri);
			break;
		case CSS_LIST_STYLE_IMAGE_NOT_SET:
			break;
		default:
			fprintf(stream, " UNKNOWN");
		}
		fprintf(stream, "; ");
	}

	if (style->margin[0].margin != CSS_MARGIN_NOT_SET ||
			style->margin[1].margin != CSS_MARGIN_NOT_SET ||
			style->margin[2].margin != CSS_MARGIN_NOT_SET ||
			style->margin[3].margin != CSS_MARGIN_NOT_SET) {
		fprintf(stream, "margin:");
		for (i = 0; i != 4; i++) {
			switch (style->margin[i].margin) {
			case CSS_MARGIN_INHERIT:
				fprintf(stream, " inherit");
				break;
			case CSS_MARGIN_LENGTH:
				fprintf(stream, " ");
				css_dump_length(stream,
						&style->margin[i].value.length);
				break;
			case CSS_MARGIN_PERCENT:
				fprintf(stream, " %g%%",
					style->margin[i].value.percent);
				break;
			case CSS_MARGIN_AUTO:
				fprintf(stream, " auto");
				break;
			case CSS_MARGIN_NOT_SET:
				fprintf(stream, " .");
				break;
			default:
				fprintf(stream, " UNKNOWN");
				break;
			}
		}
		fprintf(stream, "; ");
	}

	if (style->max_height.max_height != CSS_MAX_HEIGHT_NOT_SET) {
		fprintf(stream, "max-height: ");
		switch (style->max_height.max_height) {
		case CSS_MAX_HEIGHT_INHERIT:
			fprintf(stream, "inherit");
			break;
		case CSS_MAX_HEIGHT_NONE:
			fprintf(stream, "none");
			break;
		case CSS_MAX_HEIGHT_LENGTH:
			css_dump_length(stream,
					&style->max_height.value.length);
			break;
		case CSS_MAX_HEIGHT_PERCENT:
			fprintf(stream, "%g%%",
				style->max_height.value.percent);
			break;
		default:
			fprintf(stream, "UNKNOWN");
			break;
		}
		fprintf(stream, "; ");
	}

	if (style->max_width.max_width != CSS_MAX_WIDTH_NOT_SET) {
		fprintf(stream, "max-width: ");
		switch (style->max_width.max_width) {
		case CSS_MAX_WIDTH_INHERIT:
			fprintf(stream, "inherit");
			break;
		case CSS_MAX_WIDTH_NONE:
			fprintf(stream, "none");
			break;
		case CSS_MAX_WIDTH_LENGTH:
			css_dump_length(stream, &style->max_width.value.length);
			break;
		case CSS_MAX_WIDTH_PERCENT:
			fprintf(stream, "%g%%",
				style->max_width.value.percent);
			break;
		default:
			fprintf(stream, "UNKNOWN");
			break;
		}
		fprintf(stream, "; ");
	}

	if (style->min_height.min_height != CSS_MIN_HEIGHT_NOT_SET) {
		fprintf(stream, "min-height: ");
		switch (style->min_height.min_height) {
		case CSS_MIN_HEIGHT_INHERIT:
			fprintf(stream, "inherit");
			break;
		case CSS_MIN_HEIGHT_LENGTH:
			css_dump_length(stream,
					&style->min_height.value.length);
			break;
		case CSS_MIN_HEIGHT_PERCENT:
			fprintf(stream, "%g%%",
				style->min_height.value.percent);
			break;
		default:
			fprintf(stream, "UNKNOWN");
			break;
		}
		fprintf(stream, "; ");
	}

	if (style->min_width.min_width != CSS_MIN_WIDTH_NOT_SET) {
		fprintf(stream, "min-width: ");
		switch (style->min_width.min_width) {
		case CSS_MIN_WIDTH_INHERIT:
			fprintf(stream, "inherit");
			break;
		case CSS_MIN_WIDTH_LENGTH:
			css_dump_length(stream, &style->min_width.value.length);
			break;
		case CSS_MIN_WIDTH_PERCENT:
			fprintf(stream, "%g%%",
				style->min_width.value.percent);
			break;
		default:
			fprintf(stream, "UNKNOWN");
			break;
		}
		fprintf(stream, "; ");
	}

	if (style->orphans.orphans != CSS_ORPHANS_NOT_SET) {
		fprintf(stream, "orphans: ");
		switch (style->orphans.orphans) {
		case CSS_ORPHANS_INHERIT:
			fprintf(stream, "inherit");
			break;
		case CSS_ORPHANS_INTEGER:
			fprintf(stream, "%d",
				style->orphans.value);
			break;
		default:
			fprintf(stream, "UNKNOWN");
			break;
		}
		fprintf(stream, "; ");
	}

	if (style->outline.color.color != CSS_OUTLINE_COLOR_NOT_SET ||
		style->outline.width.width != CSS_BORDER_WIDTH_NOT_SET ||
		style->outline.style != CSS_BORDER_STYLE_NOT_SET) {
		fprintf(stream, "outline:");
		switch (style->outline.color.color) {
		case CSS_OUTLINE_COLOR_INHERIT:
			fprintf(stream, " inherit");
			break;
		case CSS_OUTLINE_COLOR_INVERT:
			fprintf(stream, " invert");
			break;
		case CSS_OUTLINE_COLOR_COLOR:
			if (style->outline.color.value == TRANSPARENT)
				fprintf(stream, " transparent");
			else if (style->outline.color.value == CSS_COLOR_NONE)
				fprintf(stream, " none");
			else if (style->outline.color.value == CSS_COLOR_INHERIT)
				fprintf(stream, " inherit");
			else if (style->outline.color.value == CSS_COLOR_NOT_SET)
				fprintf(stream, " .");
			else
				fprintf(stream, " #%.6x", style->outline.color.value);
			break;
		case CSS_OUTLINE_COLOR_NOT_SET:
			break;
		default:
			fprintf(stream, " UNKNOWN");
			break;
		}

		if (style->outline.style == CSS_BORDER_STYLE_UNKNOWN)
			fprintf(stream, " UNKNOWN");
		else if (style->outline.style == CSS_BORDER_STYLE_NOT_SET)
			;
		else
			fprintf(stream, " %s",
				css_border_style_name[style->outline.style]);

		switch (style->outline.width.width) {
		case CSS_BORDER_WIDTH_INHERIT:
			fprintf(stream, " inherit");
			break;
		case CSS_BORDER_WIDTH_LENGTH:
			fprintf(stream, " ");
			css_dump_length(stream, &style->outline.width.value);
			break;
		case CSS_BORDER_WIDTH_NOT_SET:
			break;
		default:
			fprintf(stream, " UNKNOWN");
			break;
		}
		fprintf(stream, "; ");
	}

	DUMP_KEYWORD(overflow, "overflow", css_overflow_name);

	if (style->padding[0].padding != CSS_PADDING_NOT_SET ||
			style->padding[1].padding != CSS_PADDING_NOT_SET ||
			style->padding[2].padding != CSS_PADDING_NOT_SET ||
			style->padding[3].padding != CSS_PADDING_NOT_SET) {
		fprintf(stream, "padding:");
		for (i = 0; i != 4; i++) {
			switch (style->padding[i].padding) {
			case CSS_PADDING_INHERIT:
				fprintf(stream, " inherit");
				break;
			case CSS_PADDING_LENGTH:
				fprintf(stream, " ");
				css_dump_length(stream,
					&style->padding[i].value.length);
				break;
			case CSS_PADDING_PERCENT:
				fprintf(stream, " %g%%",
					style->padding[i].value.percent);
				break;
			case CSS_PADDING_NOT_SET:
				fprintf(stream, " .");
				break;
			default:
				fprintf(stream, " UNKNOWN");
				break;
			}
		}
		fprintf(stream, "; ");
	}

	DUMP_KEYWORD(page_break_after, "page-break-after",
			css_page_break_after_name);
	DUMP_KEYWORD(page_break_before, "page-break-before",
			css_page_break_before_name);
	DUMP_KEYWORD(page_break_inside, "page-break-inside",
			css_page_break_inside_name);

	for (i = 0; i != 4; i++) {
		if (style->pos[i].pos != CSS_POS_NOT_SET) {
			switch (i) {
			case TOP:
				fprintf(stream, "top: ");
				break;
			case RIGHT:
				fprintf(stream, "right: ");
				break;
			case BOTTOM:
				fprintf(stream, "bottom: ");
				break;
			case LEFT:
				fprintf(stream, "left: ");
				break;
			}
			switch (style->pos[i].pos) {
			case CSS_POS_INHERIT:
				fprintf(stream, "inherit");
				break;
			case CSS_POS_AUTO:
				fprintf(stream, "auto");
				break;
			case CSS_POS_PERCENT:
				fprintf(stream, "%g%%",
						style->pos[i].value.percent);
				break;
			case CSS_POS_LENGTH:
				css_dump_length(stream,
						&style->pos[i].value.length);
				break;
			default:
				fprintf(stream, "UNKNOWN");
				break;
			}
			fprintf(stream, "; ");
		}
	}
	DUMP_KEYWORD(position, "position", css_position_name);

	DUMP_KEYWORD(table_layout, "table-layout", css_table_layout_name);
	DUMP_KEYWORD(text_align, "text-align", css_text_align_name);

	if (style->text_decoration != CSS_TEXT_DECORATION_NOT_SET) {
		fprintf(stream, "text-decoration:");
		if (style->text_decoration == CSS_TEXT_DECORATION_NONE)
			fprintf(stream, " none");
		if (style->text_decoration == CSS_TEXT_DECORATION_INHERIT)
			fprintf(stream, " inherit");
		if (style->text_decoration & CSS_TEXT_DECORATION_UNDERLINE)
			fprintf(stream, " underline");
		if (style->text_decoration & CSS_TEXT_DECORATION_OVERLINE)
			fprintf(stream, " overline");
		if (style->text_decoration & CSS_TEXT_DECORATION_LINE_THROUGH)
			fprintf(stream, " line-through");
		if (style->text_decoration & CSS_TEXT_DECORATION_BLINK)
			fprintf(stream, " blink");
		fprintf(stream, "; ");
	}

	if (style->text_indent.size != CSS_TEXT_INDENT_NOT_SET) {
		fprintf(stream, "text-indent: ");
		switch (style->text_indent.size) {
		case CSS_TEXT_INDENT_LENGTH:
			css_dump_length(stream,
					&style->text_indent.value.length);
			break;
		case CSS_TEXT_INDENT_PERCENT:
			fprintf(stream, "%g%%",
				style->text_indent.value.percent);
			break;
		case CSS_TEXT_INDENT_INHERIT:
			fprintf(stream, "inherit");
			break;
		default:
			fprintf(stream, "UNKNOWN");
			break;
		}
		fprintf(stream, "; ");
	}

	DUMP_KEYWORD(text_transform, "text-transform", css_text_transform_name);

	DUMP_KEYWORD(unicode_bidi, "unicode-bidi", css_unicode_bidi_name);

	if (style->vertical_align.type != CSS_VERTICAL_ALIGN_NOT_SET) {
		fprintf(stream, "vertical-align: ");
		switch (style->vertical_align.type) {
		case CSS_VERTICAL_ALIGN_INHERIT:
			fprintf(stream, "inherit");
			break;
		case CSS_VERTICAL_ALIGN_BASELINE:
			fprintf(stream, "baseline");
			break;
		case CSS_VERTICAL_ALIGN_SUB:
			fprintf(stream, "sub");
			break;
		case CSS_VERTICAL_ALIGN_SUPER:
			fprintf(stream, "super");
			break;
		case CSS_VERTICAL_ALIGN_TOP:
			fprintf(stream, "top");
			break;
		case CSS_VERTICAL_ALIGN_TEXT_TOP:
			fprintf(stream, "text-top");
			break;
		case CSS_VERTICAL_ALIGN_MIDDLE:
			fprintf(stream, "middle");
			break;
		case CSS_VERTICAL_ALIGN_BOTTOM:
			fprintf(stream, "bottom");
			break;
		case CSS_VERTICAL_ALIGN_TEXT_BOTTOM:
			fprintf(stream, "text-bottom");
			break;
		case CSS_VERTICAL_ALIGN_LENGTH:
			css_dump_length(stream,
					&style->vertical_align.value.length);
			break;
		case CSS_VERTICAL_ALIGN_PERCENT:
			fprintf(stream, "%g%%",
				style->vertical_align.value.percent);
			break;
		default:
			fprintf(stream, "UNKNOWN");
			break;
		}
		fprintf(stream, "; ");
	}

	DUMP_KEYWORD(visibility, "visibility", css_visibility_name);
	DUMP_KEYWORD(white_space, "white-space", css_white_space_name);

	if (style->widows.widows != CSS_WIDOWS_NOT_SET) {
		fprintf(stream, "widows: ");
		switch (style->widows.widows) {
		case CSS_WIDOWS_INHERIT:
			fprintf(stream, "inherit");
			break;
		case CSS_WIDOWS_INTEGER:
			fprintf(stream, "%d",
				style->widows.value);
			break;
		default:
			fprintf(stream, "UNKNOWN");
			break;
		}
		fprintf(stream, "; ");
	}

	if (style->width.width != CSS_WIDTH_NOT_SET) {
		fprintf(stream, "width: ");
		switch (style->width.width) {
		case CSS_WIDTH_INHERIT:
			fprintf(stream, "inherit");
			break;
		case CSS_WIDTH_AUTO:
			fprintf(stream, "auto");
			break;
		case CSS_WIDTH_LENGTH:
			css_dump_length(stream, &style->width.value.length);
			break;
		case CSS_WIDTH_PERCENT:
			fprintf(stream, "%g%%", style->width.value.percent);
			break;
		default:
			fprintf(stream, "UNKNOWN");
			break;
		}
		fprintf(stream, "; ");
	}

	if (style->word_spacing.word_spacing != CSS_WORD_SPACING_NOT_SET) {
		fprintf(stream, "word-spacing: ");
		switch (style->word_spacing.word_spacing) {
		case CSS_WORD_SPACING_INHERIT:
			fprintf(stream, "inherit");
			break;
		case CSS_WORD_SPACING_NORMAL:
			fprintf(stream, "normal");
			break;
		case CSS_WORD_SPACING_LENGTH:
			css_dump_length(stream, &style->word_spacing.length);
			break;
		default:
			fprintf(stream, "UNKNOWN");
			break;
		}
		fprintf(stream, "; ");
	}

	if (style->z_index.z_index != CSS_Z_INDEX_NOT_SET) {
		fprintf(stream, "z-index: ");
		switch (style->z_index.z_index) {
		case CSS_Z_INDEX_INHERIT:
			fprintf(stream, "inherit");
			break;
		case CSS_Z_INDEX_AUTO:
			fprintf(stream, "auto");
			break;
		case CSS_Z_INDEX_INTEGER:
			fprintf(stream, "%d",
				style->z_index.value);
			break;
		default:
			fprintf(stream, "UNKNOWN");
			break;
		}
		fprintf(stream, "; ");
	}

	fprintf(stream, "}");
}


/**
 * Dump a css_length to the given stream
 */

void css_dump_length(FILE *stream, const struct css_length * const length)
{
	if (fabs(length->value) < 0.0001)
		fprintf(stream, "0");
	else
		fprintf(stream, "%g%s", length->value,
				css_unit_name[length->unit]);
}

#ifdef DEBUG_WORKING_STYLESHEET
/**
 * Dump a complete css_working_stylesheet to stderr in CSS syntax.
 */

void css_dump_working_stylesheet(const struct css_working_stylesheet *ws)
{
	unsigned int i, j;

	for (i = 0; i != HASH_SIZE; i++) {
		/*fprintf(stderr, "hash %i:\n", i);*/
		for (j = 0; ws->rule[i][j]; j++) {
			css_dump_selector(ws->rule[i][j]);
			fprintf(stderr, " <%lx> ", ws->rule[i][j]->specificity);
			css_dump_style(ws->rule[i][j]->style);
			fprintf(stderr, "\n");
		}
	}
}
#endif

/**
 * Set all members to false
 */
void css_importance_reset(struct css_importance *i) {
	int j;
	i->background_color = false;
	i->background_image = false;
	i->border_spacing = false;
	i->color = false;
	i->height = false;
	i->width = false;

	/**< top, right, bottom, left */
	for (j = 0; j < 4; j++) {
		i->border_color[j] = false;
		i->border_style[j] = false;
		i->border_width[j] = false;
		i->margin[j] = false;
		i->padding[j] = false;
	}
}

/**
 * Dump a complete css_stylesheet to stderr in CSS syntax.
 */

void css_dump_stylesheet(const struct css_stylesheet * stylesheet)
{
	unsigned int i;
	struct css_selector *r;
	for (i = 0; i != HASH_SIZE; i++) {
		/*fprintf(stderr, "hash %i:\n", i);*/
		for (r = stylesheet->rule[i]; r != 0; r = r->next) {
			css_dump_selector(r);
			fprintf(stderr, " <%lx> ", r->specificity);
			css_dump_style(stderr, r->style);
			fprintf(stderr, "\n");
		}
	}
}


/**
 * Dump a css_selector to stderr in CSS syntax.
 */

void css_dump_selector(const struct css_selector *r)
{
	struct css_selector *m;

	if (r->combiner)
		css_dump_selector(r->combiner);

	switch (r->comb) {
		case CSS_COMB_NONE:     break;
		case CSS_COMB_ANCESTOR: fprintf(stderr, " "); break;
		case CSS_COMB_PARENT:   fprintf(stderr, " > "); break;
		case CSS_COMB_PRECEDED: fprintf(stderr, " + "); break;
	}

	if (r->data)
		fprintf(stderr, "%.*s", r->data_length, r->data);
	else
		fprintf(stderr, "*");

	for (m = r->detail; m; m = m->next) {
		switch (m->type) {
			case CSS_SELECTOR_ID:
				fprintf(stderr, "#%.*s",
						m->data_length, m->data);
				break;
			case CSS_SELECTOR_CLASS:
				fprintf(stderr, ".%.*s",
						m->data_length,	m->data);
				break;
			case CSS_SELECTOR_ATTRIB:
				fprintf(stderr, "[%.*s]",
						m->data_length, m->data);
				break;
			case CSS_SELECTOR_ATTRIB_EQ:
				fprintf(stderr, "[%.*s=%.*s]",
						m->data_length,	m->data,
						m->data2_length, m->data2);
				break;
			case CSS_SELECTOR_ATTRIB_INC:
				fprintf(stderr, "[%.*s~=%.*s]",
						m->data_length, m->data,
						m->data2_length, m->data2);
				break;
			case CSS_SELECTOR_ATTRIB_DM:
				fprintf(stderr, "[%.*s|=%.*s]",
						m->data_length, m->data,
						m->data2_length, m->data2);
				break;
			case CSS_SELECTOR_ATTRIB_PRE:
				fprintf(stderr, "[%.*s^=%.*s]",
						m->data_length, m->data,
						m->data2_length, m->data2);
				break;
			case CSS_SELECTOR_ATTRIB_SUF:
				fprintf(stderr, "[%.*s$=%.*s]",
						m->data_length, m->data,
						m->data2_length, m->data2);
				break;
			case CSS_SELECTOR_ATTRIB_SUB:
				fprintf(stderr, "[%.*s*=%.*s]",
						m->data_length, m->data,
						m->data2_length, m->data2);
				break;
			case CSS_SELECTOR_PSEUDO:
				fprintf(stderr, ":%.*s",
						m->data_length, m->data);
				break;
			default:
				fprintf(stderr, "(unexpected detail)");
		}
	}
}


/**
 * Cascade styles.
 *
 * \param  style	   css_style to modify
 * \param  apply	   css_style to cascade onto style
 * \param  author	   updated to indicate which properties have greater
 *			   than author level CSS importance. (NULL if
 *			   importance isn't required.)
 *
 * Attributes which have the value 'inherit' or 'unset' in apply are
 * unchanged in style.
 * Other attributes are copied to style, calculating percentages relative to
 * style where applicable.
 */

void css_cascade(struct css_style * const style,
		const struct css_style * const apply,
		struct css_importance * const author)
{
	unsigned int i;
	float f;

	if (apply->background_attachment !=
			CSS_BACKGROUND_ATTACHMENT_INHERIT &&
				apply->background_attachment !=
					CSS_BACKGROUND_ATTACHMENT_NOT_SET)
		style->background_attachment = apply->background_attachment;
	if (apply->background_color != CSS_COLOR_INHERIT &&
			apply->background_color != CSS_COLOR_NOT_SET)
		style->background_color = apply->background_color;
	if (apply->background_image.type != CSS_BACKGROUND_IMAGE_INHERIT &&
			apply->background_image.type !=
				CSS_BACKGROUND_IMAGE_NOT_SET)
		style->background_image = apply->background_image;
	if (apply->background_repeat != CSS_BACKGROUND_REPEAT_INHERIT &&
			apply->background_repeat !=
				CSS_BACKGROUND_REPEAT_NOT_SET)
		style->background_repeat = apply->background_repeat;
	if (apply->border_collapse != CSS_BORDER_COLLAPSE_INHERIT &&
			apply->border_collapse != CSS_BORDER_COLLAPSE_NOT_SET)
		style->border_collapse = apply->border_collapse;
	if (apply->border_spacing.border_spacing !=
			CSS_BORDER_SPACING_INHERIT &&
				apply->border_spacing.border_spacing !=
					CSS_BORDER_SPACING_NOT_SET)
		style->border_spacing = apply->border_spacing;
	if (apply->caption_side != CSS_CAPTION_SIDE_INHERIT &&
			apply->caption_side != CSS_CAPTION_SIDE_NOT_SET)
		style->caption_side = apply->caption_side;
	if (apply->clear != CSS_CLEAR_INHERIT &&
			apply->clear != CSS_CLEAR_NOT_SET)
		style->clear = apply->clear;
	if (apply->color != CSS_COLOR_INHERIT &&
			apply->color != CSS_COLOR_NOT_SET)
		style->color = apply->color;
	if (apply->content.type != CSS_CONTENT_INHERIT &&
			apply->content.type != CSS_CONTENT_NOT_SET)
		style->content = apply->content;
	if (apply->counter_reset.type != CSS_COUNTER_RESET_INHERIT &&
			apply->counter_reset.type != CSS_COUNTER_RESET_NOT_SET)
		style->counter_reset = apply->counter_reset;
	if (apply->counter_increment.type != CSS_COUNTER_INCREMENT_INHERIT &&
			apply->counter_increment.type != CSS_COUNTER_INCREMENT_NOT_SET)
		style->counter_increment = apply->counter_increment;
	if (apply->cursor != CSS_CURSOR_INHERIT &&
			apply->cursor != CSS_CURSOR_NOT_SET)
		style->cursor = apply->cursor;
	if (apply->direction != CSS_DIRECTION_INHERIT &&
			apply->direction != CSS_DIRECTION_NOT_SET)
		style->direction = apply->direction;
	if (apply->display != CSS_DISPLAY_INHERIT &&
			apply->display != CSS_DISPLAY_NOT_SET)
		style->display = apply->display;
	if (apply->empty_cells != CSS_EMPTY_CELLS_INHERIT &&
			apply->empty_cells != CSS_EMPTY_CELLS_NOT_SET)
		style->empty_cells = apply->empty_cells;
	if (apply->float_ != CSS_FLOAT_INHERIT &&
			apply->float_ != CSS_FLOAT_NOT_SET)
		style->float_ = apply->float_;
	if (apply->font_family != CSS_FONT_FAMILY_INHERIT &&
			apply->font_family != CSS_FONT_FAMILY_NOT_SET)
		style->font_family = apply->font_family;
	if (apply->font_style != CSS_FONT_STYLE_INHERIT &&
			apply->font_style != CSS_FONT_STYLE_NOT_SET)
		style->font_style = apply->font_style;
	if (apply->font_variant != CSS_FONT_VARIANT_INHERIT &&
			apply->font_variant != CSS_FONT_VARIANT_NOT_SET)
		style->font_variant = apply->font_variant;
	if (apply->font_weight != CSS_FONT_WEIGHT_INHERIT &&
			apply->font_weight != CSS_FONT_WEIGHT_NOT_SET)
		style->font_weight = apply->font_weight;
	if (apply->height.height != CSS_HEIGHT_INHERIT &&
			apply->height.height != CSS_HEIGHT_NOT_SET)
		style->height = apply->height;
	if (apply->letter_spacing.letter_spacing !=
			CSS_LETTER_SPACING_INHERIT &&
				apply->letter_spacing.letter_spacing !=
					CSS_LETTER_SPACING_NOT_SET)
		style->letter_spacing = apply->letter_spacing;
	if (apply->line_height.size != CSS_LINE_HEIGHT_INHERIT &&
			apply->line_height.size != CSS_LINE_HEIGHT_NOT_SET)
		style->line_height = apply->line_height;
	if (apply->list_style_image.type != CSS_LIST_STYLE_IMAGE_INHERIT &&
			apply->list_style_image.type !=
				CSS_LIST_STYLE_IMAGE_NOT_SET)
		style->list_style_image = apply->list_style_image;
	if (apply->list_style_position != CSS_LIST_STYLE_POSITION_INHERIT &&
			apply->list_style_position !=
				CSS_LIST_STYLE_POSITION_NOT_SET)
		style->list_style_position = apply->list_style_position;
	if (apply->list_style_type != CSS_LIST_STYLE_TYPE_INHERIT &&
			apply->list_style_type != CSS_LIST_STYLE_TYPE_NOT_SET)
		style->list_style_type = apply->list_style_type;
	if (apply->max_height.max_height != CSS_MAX_HEIGHT_INHERIT &&
			apply->max_height.max_height != CSS_MAX_HEIGHT_NOT_SET)
		style->max_height = apply->max_height;
	if (apply->max_width.max_width != CSS_MAX_WIDTH_INHERIT &&
			apply->max_width.max_width != CSS_MAX_WIDTH_NOT_SET)
		style->max_width = apply->max_width;
	if (apply->min_height.min_height != CSS_MIN_HEIGHT_INHERIT &&
			apply->min_height.min_height != CSS_MIN_HEIGHT_NOT_SET)
		style->min_height = apply->min_height;
	if (apply->min_width.min_width != CSS_MIN_WIDTH_INHERIT &&
			apply->min_width.min_width != CSS_MIN_WIDTH_NOT_SET)
		style->min_width = apply->min_width;
	if (apply->orphans.orphans != CSS_ORPHANS_INHERIT &&
			apply->orphans.orphans != CSS_ORPHANS_NOT_SET)
		style->orphans = apply->orphans;
	if (apply->overflow != CSS_OVERFLOW_INHERIT &&
			apply->overflow != CSS_OVERFLOW_NOT_SET)
		style->overflow = apply->overflow;
	if (apply->page_break_after != CSS_PAGE_BREAK_AFTER_INHERIT &&
			apply->page_break_after !=
				CSS_PAGE_BREAK_AFTER_NOT_SET)
		style->page_break_after = apply->page_break_after;
	if (apply->page_break_before != CSS_PAGE_BREAK_BEFORE_INHERIT &&
			apply->page_break_before !=
				CSS_PAGE_BREAK_BEFORE_NOT_SET)
		style->page_break_before = apply->page_break_before;
	if (apply->page_break_inside != CSS_PAGE_BREAK_INSIDE_INHERIT &&
			apply->page_break_inside !=
				CSS_PAGE_BREAK_INSIDE_NOT_SET)
		style->page_break_inside = apply->page_break_inside;
	if (apply->position != CSS_POSITION_INHERIT &&
			apply->position != CSS_POSITION_NOT_SET)
		style->position = apply->position;
	if (apply->table_layout != CSS_TABLE_LAYOUT_INHERIT &&
			apply->table_layout != CSS_TABLE_LAYOUT_NOT_SET)
		style->table_layout = apply->table_layout;
	if (apply->text_align != CSS_TEXT_ALIGN_INHERIT &&
			apply->text_align != CSS_TEXT_ALIGN_NOT_SET)
		style->text_align = apply->text_align;
	/* text-decoration: approximate CSS 2.1 by inheriting into inline elements */
	if (apply->text_decoration != CSS_TEXT_DECORATION_INHERIT &&
			apply->text_decoration != CSS_TEXT_DECORATION_NOT_SET)
		style->text_decoration = apply->text_decoration;
	if (apply->text_indent.size != CSS_TEXT_INDENT_INHERIT &&
			apply->text_indent.size != CSS_TEXT_INDENT_NOT_SET)
		style->text_indent = apply->text_indent;
	if (apply->text_transform != CSS_TEXT_TRANSFORM_INHERIT &&
			apply->text_transform != CSS_TEXT_TRANSFORM_NOT_SET)
		style->text_transform = apply->text_transform;
	if (apply->unicode_bidi != CSS_UNICODE_BIDI_INHERIT &&
			apply->unicode_bidi != CSS_UNICODE_BIDI_NOT_SET)
		style->unicode_bidi = apply->unicode_bidi;
	if (apply->vertical_align.type != CSS_VERTICAL_ALIGN_INHERIT &&
			apply->vertical_align.type !=
				CSS_VERTICAL_ALIGN_NOT_SET)
		style->vertical_align = apply->vertical_align;
	if (apply->visibility != CSS_VISIBILITY_INHERIT &&
			apply->visibility != CSS_VISIBILITY_NOT_SET)
		style->visibility = apply->visibility;
	if (apply->white_space != CSS_WHITE_SPACE_INHERIT &&
			apply->white_space != CSS_WHITE_SPACE_NOT_SET)
		style->white_space = apply->white_space;
	if (apply->widows.widows != CSS_WIDOWS_INHERIT &&
			apply->widows.widows != CSS_WIDOWS_NOT_SET)
		style->widows = apply->widows;
	if (apply->width.width != CSS_WIDTH_INHERIT &&
			apply->width.width != CSS_WIDTH_NOT_SET)
		style->width = apply->width;
	if (apply->word_spacing.word_spacing != CSS_WORD_SPACING_INHERIT &&
			apply->word_spacing.word_spacing !=
				CSS_WORD_SPACING_NOT_SET)
		style->word_spacing = apply->word_spacing;
	if (apply->z_index.z_index != CSS_Z_INDEX_INHERIT &&
			apply->z_index.z_index != CSS_Z_INDEX_NOT_SET)
		style->z_index = apply->z_index;


	/* clip */
	if (apply->clip.clip != CSS_CLIP_INHERIT &&
			apply->clip.clip != CSS_CLIP_NOT_SET) {
		for (i = 0; i != 4; i++) {
			style->clip.rect[i] = apply->clip.rect[i];
		}
	}


        /* background-position */
	if (apply->background_position.horz.pos !=
			CSS_BACKGROUND_POSITION_INHERIT &&
				apply->background_position.horz.pos !=
					CSS_BACKGROUND_POSITION_NOT_SET) {
		style->background_position.horz =
				apply->background_position.horz;
	}
	if (apply->background_position.vert.pos !=
			CSS_BACKGROUND_POSITION_INHERIT &&
				apply->background_position.vert.pos !=
					CSS_BACKGROUND_POSITION_NOT_SET) {
		style->background_position.vert =
				apply->background_position.vert;
	}

	/* font-size */
	f = apply->font_size.value.percent / 100;
	switch (apply->font_size.size) {
		case CSS_FONT_SIZE_ABSOLUTE:
			style->font_size = apply->font_size;
			break;
		case CSS_FONT_SIZE_LENGTH:
			switch (apply->font_size.value.length.unit) {
				case CSS_UNIT_EM:
					f = apply->font_size.value.length.value;
					break;
				case CSS_UNIT_EX:
					f = apply->font_size.value.length.value * 0.6 /*?*/;
					break;
				default:
					style->font_size = apply->font_size;
			}
			if ((apply->font_size.value.length.unit != CSS_UNIT_EM) &&
			    (apply->font_size.value.length.unit != CSS_UNIT_EX))
				break;
			/* drop through if EM or EX */
		case CSS_FONT_SIZE_PERCENT:
			switch (style->font_size.size) {
				case CSS_FONT_SIZE_ABSOLUTE:
					style->font_size.value.absolute *= f;
					break;
				case CSS_FONT_SIZE_LENGTH:
					style->font_size.value.length.value *= f;
					break;
				default:
					die("attempting percentage of unknown font-size");
			}
			break;
		case CSS_FONT_SIZE_INHERIT:
		case CSS_FONT_SIZE_NOT_SET:
		default:                     /* leave unchanged */
			break;
	}

	/* outline */
	if (apply->outline.color.color != CSS_OUTLINE_COLOR_INHERIT &&
			apply->outline.color.color !=
				CSS_OUTLINE_COLOR_NOT_SET)
		style->outline.color = apply->outline.color;
	if (apply->outline.width.width != CSS_BORDER_WIDTH_INHERIT &&
			apply->outline.width.width != CSS_BORDER_WIDTH_NOT_SET)
		style->outline.width = apply->outline.width;
	if (apply->outline.style != CSS_BORDER_STYLE_INHERIT &&
			apply->outline.style != CSS_BORDER_STYLE_NOT_SET)
		style->outline.style = apply->outline.style;

	/* borders, margins, padding and box position */
	for (i = 0; i != 4; i++) {
		if (apply->border[i].color != CSS_COLOR_INHERIT &&
				apply->border[i].color != CSS_COLOR_NOT_SET)
			style->border[i].color = apply->border[i].color;
		if (apply->border[i].width.width !=
				CSS_BORDER_WIDTH_INHERIT &&
					apply->border[i].width.width !=
						CSS_BORDER_WIDTH_NOT_SET)
			style->border[i].width = apply->border[i].width;
		if (apply->border[i].style != CSS_BORDER_STYLE_INHERIT &&
				apply->border[i].style !=
					CSS_BORDER_STYLE_NOT_SET)
			style->border[i].style = apply->border[i].style;

		if (apply->margin[i].margin != CSS_MARGIN_INHERIT &&
				apply->margin[i].margin != CSS_MARGIN_NOT_SET)
			style->margin[i] = apply->margin[i];

		if (apply->padding[i].padding != CSS_PADDING_INHERIT &&
				apply->padding[i].padding !=
					CSS_PADDING_NOT_SET)
			style->padding[i] = apply->padding[i];

		if (apply->pos[i].pos != CSS_POS_INHERIT &&
				apply->pos[i].pos != CSS_POS_NOT_SET)
			style->pos[i] = apply->pos[i];
	}

	/* Set author level CSS importance (used for HTML style attribute) */
	if (author) {
		if (apply->background_color != CSS_COLOR_NOT_SET)
			author->background_color = true;
		if (apply->background_image.type !=
					CSS_BACKGROUND_IMAGE_NOT_SET)
			author->background_image = true;
		if (apply->border_spacing.border_spacing !=
					CSS_BORDER_SPACING_NOT_SET)
			author->border_spacing = true;
		if (apply->color != CSS_COLOR_NOT_SET)
			author->color = true;
		if (apply->height.height != CSS_HEIGHT_NOT_SET)
			author->height = true;
		if (apply->width.width != CSS_WIDTH_NOT_SET)
			author->width = true;

		for (i = 0; i != 4; i++) {
			if (apply->border[i].color != CSS_COLOR_NOT_SET)
				author->border_color[i] = true;
			if (apply->border[i].width.width !=
						CSS_BORDER_WIDTH_NOT_SET)
				author->border_width[i] = true;
			if (apply->border[i].style != CSS_BORDER_STYLE_NOT_SET)
				author->border_style[i] = true;

			if (apply->margin[i].margin != CSS_MARGIN_NOT_SET)
				author->margin[i] = true;

			if (apply->padding[i].padding != CSS_PADDING_NOT_SET)
				author->padding[i] = true;
		}
	}
}


/**
 * Merge styles.
 *
 * \param  style        css_style to modify
 * \param  apply        css_style to merge onto style
 * \param  specificity  specificity of current CSS rule
 * \param  author       updated to indicate which properties have greater than
 *                      author level CSS importance
 *
 * Attributes which have the value 'unset' in apply are unchanged in style.
 * Other attributes are copied to style, overwriting it.
 */

void css_merge(struct css_style * const style,
		const struct css_style * const apply,
		const unsigned long specificity,
		struct css_importance * const author)
{
	unsigned int i;

	if (apply->background_attachment != CSS_BACKGROUND_ATTACHMENT_NOT_SET)
		style->background_attachment = apply->background_attachment;
	if (apply->background_color != CSS_COLOR_NOT_SET) {
		style->background_color = apply->background_color;
		if (specificity >= CSS_SPECIFICITY_AUTHOR)
			author->background_color = true;
	}
	if (apply->background_image.type != CSS_BACKGROUND_IMAGE_NOT_SET) {
		style->background_image = apply->background_image;
		if (specificity >= CSS_SPECIFICITY_AUTHOR)
			author->background_image = true;
	}
	if (apply->background_repeat != CSS_BACKGROUND_REPEAT_NOT_SET)
		style->background_repeat = apply->background_repeat;
	if (apply->border_collapse != CSS_BORDER_COLLAPSE_NOT_SET)
		style->border_collapse = apply->border_collapse;
	if (apply->border_spacing.border_spacing != CSS_BORDER_SPACING_NOT_SET){
		style->border_spacing = apply->border_spacing;
		if (specificity >= CSS_SPECIFICITY_AUTHOR)
			author->border_spacing = true;
	}
	if (apply->caption_side != CSS_CAPTION_SIDE_NOT_SET)
		style->caption_side = apply->caption_side;
	if (apply->clear != CSS_CLEAR_NOT_SET)
		style->clear = apply->clear;
	if (apply->color != CSS_COLOR_NOT_SET) {
		style->color = apply->color;
		if (specificity >= CSS_SPECIFICITY_AUTHOR)
			author->color = true;
	}
	if (apply->content.type != CSS_CONTENT_NOT_SET)
		style->content = apply->content;
	if (apply->counter_reset.type != CSS_COUNTER_RESET_NOT_SET)
		style->counter_reset = apply->counter_reset;
	if (apply->counter_increment.type != CSS_COUNTER_INCREMENT_NOT_SET)
		style->counter_increment = apply->counter_increment;
	if (apply->cursor != CSS_CURSOR_NOT_SET)
		style->cursor = apply->cursor;
	if (apply->direction != CSS_DIRECTION_NOT_SET)
		style->direction = apply->direction;
	if (apply->display != CSS_DISPLAY_NOT_SET)
		style->display = apply->display;
	if (apply->empty_cells != CSS_EMPTY_CELLS_NOT_SET)
		style->empty_cells = apply->empty_cells;
	if (apply->float_ != CSS_FLOAT_NOT_SET)
		style->float_ = apply->float_;
	if (apply->font_family != CSS_FONT_FAMILY_NOT_SET)
		style->font_family = apply->font_family;
	if (apply->font_size.size != CSS_FONT_SIZE_NOT_SET)
		style->font_size = apply->font_size;
	if (apply->font_style != CSS_FONT_STYLE_NOT_SET)
		style->font_style = apply->font_style;
	if (apply->font_variant != CSS_FONT_VARIANT_NOT_SET)
		style->font_variant = apply->font_variant;
	if (apply->font_weight != CSS_FONT_WEIGHT_NOT_SET)
		style->font_weight = apply->font_weight;
	if (apply->height.height != CSS_HEIGHT_NOT_SET) {
		style->height = apply->height;
		if (specificity >= CSS_SPECIFICITY_AUTHOR)
			author->height = true;
	}
	if (apply->letter_spacing.letter_spacing != CSS_LETTER_SPACING_NOT_SET)
		style->letter_spacing = apply->letter_spacing;
	if (apply->line_height.size != CSS_LINE_HEIGHT_NOT_SET)
		style->line_height = apply->line_height;
	if (apply->list_style_image.type != CSS_LIST_STYLE_IMAGE_NOT_SET)
		style->list_style_image = apply->list_style_image;
	if (apply->list_style_position != CSS_LIST_STYLE_POSITION_NOT_SET)
		style->list_style_position = apply->list_style_position;
	if (apply->list_style_type != CSS_LIST_STYLE_TYPE_NOT_SET)
		style->list_style_type = apply->list_style_type;
	if (apply->max_height.max_height != CSS_MAX_HEIGHT_NOT_SET)
		style->max_height = apply->max_height;
	if (apply->max_width.max_width != CSS_MAX_WIDTH_NOT_SET)
		style->max_width = apply->max_width;
	if (apply->min_height.min_height != CSS_MIN_HEIGHT_NOT_SET)
		style->min_height = apply->min_height;
	if (apply->min_width.min_width != CSS_MIN_WIDTH_NOT_SET)
		style->min_width = apply->min_width;
	if (apply->orphans.orphans != CSS_ORPHANS_NOT_SET)
		style->orphans = apply->orphans;
	if (apply->overflow != CSS_OVERFLOW_NOT_SET)
		style->overflow = apply->overflow;
	if (apply->page_break_after != CSS_PAGE_BREAK_AFTER_NOT_SET)
		style->page_break_after = apply->page_break_after;
	if (apply->page_break_before != CSS_PAGE_BREAK_BEFORE_NOT_SET)
		style->page_break_before = apply->page_break_before;
	if (apply->page_break_inside != CSS_PAGE_BREAK_INSIDE_NOT_SET)
		style->page_break_inside = apply->page_break_inside;
	if (apply->position != CSS_POSITION_NOT_SET)
		style->position = apply->position;
	if (apply->table_layout != CSS_TABLE_LAYOUT_NOT_SET)
		style->table_layout = apply->table_layout;
	if (apply->text_align != CSS_TEXT_ALIGN_NOT_SET)
		style->text_align = apply->text_align;
	/* text-decoration: approximate CSS 2.1 by inheriting into inline elements */
	if (apply->text_decoration != CSS_TEXT_DECORATION_NOT_SET)
		style->text_decoration = apply->text_decoration;
	if (apply->text_indent.size != CSS_TEXT_INDENT_NOT_SET)
		style->text_indent = apply->text_indent;
	if (apply->text_transform != CSS_TEXT_TRANSFORM_NOT_SET)
		style->text_transform = apply->text_transform;
	if (apply->unicode_bidi != CSS_UNICODE_BIDI_NOT_SET)
		style->unicode_bidi = apply->unicode_bidi;
	if (apply->vertical_align.type != CSS_VERTICAL_ALIGN_NOT_SET)
		style->vertical_align = apply->vertical_align;
	if (apply->visibility != CSS_VISIBILITY_NOT_SET)
		style->visibility = apply->visibility;
	if (apply->white_space != CSS_WHITE_SPACE_NOT_SET)
		style->white_space = apply->white_space;
	if (apply->widows.widows != CSS_WIDOWS_NOT_SET)
		style->widows = apply->widows;
	if (apply->width.width != CSS_WIDTH_NOT_SET) {
		style->width = apply->width;
		if (specificity >= CSS_SPECIFICITY_AUTHOR)
			author->width = true;
	}
	if (apply->word_spacing.word_spacing != CSS_WORD_SPACING_NOT_SET)
		style->word_spacing = apply->word_spacing;
	if (apply->z_index.z_index != CSS_Z_INDEX_NOT_SET)
		style->z_index = apply->z_index;


	/* clip */
	if (apply->clip.clip != CSS_CLIP_NOT_SET) {
		for (i = 0; i != 4; i++) {
			style->clip.rect[i] = apply->clip.rect[i];
		}
	}

	/* background-position */
	if (apply->background_position.horz.pos !=
			CSS_BACKGROUND_POSITION_NOT_SET) {
		style->background_position.horz =
				apply->background_position.horz;
	}
	if (apply->background_position.vert.pos !=
			CSS_BACKGROUND_POSITION_NOT_SET) {
		style->background_position.vert =
				apply->background_position.vert;
	}

	/* outline */
	if (apply->outline.color.color != CSS_OUTLINE_COLOR_NOT_SET)
		style->outline.color = apply->outline.color;
	if (apply->outline.width.width != CSS_BORDER_WIDTH_NOT_SET)
		style->outline.width = apply->outline.width;
	if (apply->outline.style != CSS_BORDER_STYLE_NOT_SET)
		style->outline.style = apply->outline.style;

	/* borders, margins, padding and box position */
	for (i = 0; i != 4; i++) {
		if (apply->border[i].color != CSS_COLOR_NOT_SET) {
			style->border[i].color = apply->border[i].color;
			if (specificity >= CSS_SPECIFICITY_AUTHOR)
				author->border_color[i] = true;
		}
		if (apply->border[i].width.width != CSS_BORDER_WIDTH_NOT_SET) {
			style->border[i].width = apply->border[i].width;
			if (specificity >= CSS_SPECIFICITY_AUTHOR)
				author->border_width[i] = true;
		}
		if (apply->border[i].style != CSS_BORDER_STYLE_NOT_SET) {
			style->border[i].style = apply->border[i].style;
			if (specificity >= CSS_SPECIFICITY_AUTHOR)
				author->border_style[i] = true;
		}

		if (apply->margin[i].margin != CSS_MARGIN_NOT_SET) {
			style->margin[i] = apply->margin[i];
			if (specificity >= CSS_SPECIFICITY_AUTHOR)
				author->margin[i] = true;
		}

		if (apply->padding[i].padding != CSS_PADDING_NOT_SET) {
			style->padding[i] = apply->padding[i];
			if (specificity >= CSS_SPECIFICITY_AUTHOR)
				author->padding[i] = true;
		}

		if (apply->pos[i].pos != CSS_POS_NOT_SET)
			style->pos[i] = apply->pos[i];
	}
}


/**
 * Calculate a hash for an element name.
 *
 * The hash is case-insensitive.
 */

unsigned int css_hash(const char *s, int length)
{
	int i;
	unsigned int z = 0;
	if (s == 0)
		return 0;
	for (i = 0; i != length; i++)
		z += s[i] & 0x1f;  /* lower 5 bits, case insensitive */
	return (z % (HASH_SIZE - 1)) + 1;
}


/**
 * Convert a struct css_length to pixels.
 *
 * \param  length  css_length to convert
 * \param  style   css_style applying to length. may be 0 if the length's
 *		   unit is em or ex
 * \return	   length in pixels
 *
 * If a length's unit is em or ex, the returned length is subject to the
 * configured option_font_min_size.
 */

float css_len2px(const struct css_length *length,
		const struct css_style *style)
{
	struct css_length font;
	font.unit = CSS_UNIT_PT;

	assert(!((length->unit == CSS_UNIT_EM || length->unit == CSS_UNIT_EX) &&
			style == 0));
	switch (length->unit) {
		case CSS_UNIT_EM:
			if ((font.value = css_len2pt(&style->
					font_size.value.length, style)) <
					option_font_min_size / 10) {
				/* min font size is greater than given length so
				 * use min font size for conversion to px */
				font.value = option_font_min_size / 10;
				return length->value * css_len2px(&font, style);
			} else
				/* use given length for conversion to px */
				return length->value * css_len2px(&style->
						font_size.value.length, 0);
		case CSS_UNIT_EX:
			if ((font.value = css_len2pt(&style->
					font_size.value.length, style)) <
					option_font_min_size / 10) {
				/* min font size is greater than given length so
				 * use min font size for conversion to px */
				font.value = option_font_min_size / 10;
				return length->value * css_len2px(&font,
						style) * 0.6;
			} else
				/* use given length for conversion to px */
				return length->value * css_len2px(&style->
						font_size.value.length, 0) *
						0.6;
		case CSS_UNIT_PX: return length->value;
		/* We assume the screen and any other output has the same dpi */
		case CSS_UNIT_IN: return length->value * css_screen_dpi;
		case CSS_UNIT_CM: return length->value * css_screen_dpi / 2.54;
		case CSS_UNIT_MM: return length->value * css_screen_dpi / 25.4;
		/* 1pt = 1in/72 */
		case CSS_UNIT_PT: return length->value * css_screen_dpi / 72;
		/* 1pc = 1pt * 12 */
		case CSS_UNIT_PC: return length->value * css_screen_dpi / 6;
		default: break;
	}
	return 0;
}

/**
 * Convert a struct css_length to points.
 *
 * \param  length  css_length to convert
 * \param  style   css_style applying to length. may be 0 if the length's
 *		   unit is em or ex
 * \return	   length in points
 */

float css_len2pt(const struct css_length *length,
		const struct css_style *style)
{
	assert(!((length->unit == CSS_UNIT_EM || length->unit == CSS_UNIT_EX) &&
			style == 0));
	switch (length->unit) {
		case CSS_UNIT_EM:
			return length->value *
				css_len2pt(&style->font_size.value.length, 0);
		case CSS_UNIT_EX:
			return length->value *
				css_len2pt(&style->font_size.value.length, 0) *
				0.6;
		/* We assume the screen and any other output has the same dpi */
		case CSS_UNIT_PX: return length->value * css_screen_dpi / 72;
		/* 1pt = 1in/72 */
		case CSS_UNIT_IN: return length->value * 72;
		case CSS_UNIT_CM: return length->value * 28.452756;
		case CSS_UNIT_MM: return length->value * 2.8452756;
		case CSS_UNIT_PT: return length->value;
		/* 1pc = 1pt * 12 */
		case CSS_UNIT_PC: return length->value * 12.0;
		default: break;
	}
	return 0;
}

/**
 * Return the most 'eyecatching' border.
 *
 * \return the most eyecatching border, favoured towards test2
 */

struct css_border *css_eyecatching_border(struct css_border *test1,
		struct css_style *style1, struct css_border *test2,
		struct css_style *style2)
{
	float width1, width2;
	int impact = 0;

	assert(test1);
	assert(style1);
	assert(test2);
	assert(style2);

	/* hidden border styles always win, none always loses */
	if ((test1->style == CSS_BORDER_STYLE_HIDDEN) ||
			(test2->style == CSS_BORDER_STYLE_NONE))
		return test1;
	if ((test2->style == CSS_BORDER_STYLE_HIDDEN) ||
			(test1->style == CSS_BORDER_STYLE_NONE))
		return test2;

	/* the widest border wins */
	width1 = css_len2px(&test1->width.value, style1);
	width2 = css_len2px(&test2->width.value, style2);
	if (width1 > width2)
		return test1;
	if (width2 > width1)
		return test2;

	/* the closest to a solid line wins */
	switch (test1->style) {
		case CSS_BORDER_STYLE_DOUBLE:
			impact++;
		case CSS_BORDER_STYLE_SOLID:
			impact++;
		case CSS_BORDER_STYLE_DASHED:
			impact++;
		case CSS_BORDER_STYLE_DOTTED:
			impact++;
		case CSS_BORDER_STYLE_RIDGE:
			impact++;
		case CSS_BORDER_STYLE_OUTSET:
			impact++;
		case CSS_BORDER_STYLE_GROOVE:
			impact++;
		case CSS_BORDER_STYLE_INSET:
			impact++;
		default:
			break;
	}
	switch (test2->style) {
		case CSS_BORDER_STYLE_DOUBLE:
			impact--;
		case CSS_BORDER_STYLE_SOLID:
			impact--;
		case CSS_BORDER_STYLE_DASHED:
			impact--;
		case CSS_BORDER_STYLE_DOTTED:
			impact--;
		case CSS_BORDER_STYLE_RIDGE:
			impact--;
		case CSS_BORDER_STYLE_OUTSET:
			impact--;
		case CSS_BORDER_STYLE_GROOVE:
			impact--;
		case CSS_BORDER_STYLE_INSET:
			impact--;
		default:
			break;
	}
	if (impact > 0)
		return test1;
	return test2;
}