We return client data, not node.

desktop/textarea.c

@@ -63,6 +63,18 @@ struct textarea_utf8 {
 				 *   trailing NULL */
 };
 
+struct textarea_undo_detail {
+	unsigned int offset;	/**< Offset to detail's text in undo.text */
+	unsigned int len;	/**< Length of detail's text */
+};
+
+struct textarea_undo {
+	unsigned int next_detail;
+	struct textarea_undo_detail *details;
+
+	struct textarea_utf8 text;
+};
+
 struct textarea {
 
 	int scroll_x, scroll_y;		/**< scroll offsets for the textarea */
@@ -1337,7 +1349,7 @@ static inline void textarea_char_to_byte_offset(struct textarea_utf8 *text,
 
 
 /**
- * Replace text in a textarea
+ * Perform actual text replacment in a textarea
  *
  * \param ta		Textarea widget
  * \param b_start	Start byte index of replaced section (inclusive)
@@ -1352,7 +1364,7 @@ static inline void textarea_char_to_byte_offset(struct textarea_utf8 *text,
  * Note, b_start and b_end must be the byte offsets in ta->show, so in the
  * password textarea case, they are for ta->password.
  */
-static bool textarea_replace_text(struct textarea *ta, size_t b_start,
+static bool textarea_replace_text_internal(struct textarea *ta, size_t b_start,
 		size_t b_end, const char *rep, size_t rep_len,
 		bool add_to_clipboard, int *byte_delta, struct rect *r)
 {
@@ -1461,6 +1473,47 @@ static bool textarea_replace_text(struct textarea *ta, size_t b_start,
 }
 
 
+/**
+ * Replace text in a textarea, updating undo buffer.
+ *
+ * \param ta		Textarea widget
+ * \param b_start	Start byte index of replaced section (inclusive)
+ * \param b_end		End byte index of replaced section (exclusive)
+ * \param rep		Replacement UTF-8 text to insert
+ * \param rep_len	Byte length of replacement UTF-8 text
+ * \param add_to_clipboard	True iff replaced text to be added to clipboard
+ * \param byte_delta	Updated to change in byte count in textarea (ta->show)
+ * \param r		Updated to area where redraw is required
+ * \return false on memory exhaustion, true otherwise
+ *
+ * Note, b_start and b_end must be the byte offsets in ta->show, so in the
+ * password textarea case, they are for ta->password.
+ */
+static bool textarea_replace_text(struct textarea *ta, size_t b_start,
+		size_t b_end, const char *rep, size_t rep_len,
+		bool add_to_clipboard, int *byte_delta, struct rect *r)
+{
+	/* TODO: Make copy of any replaced text */
+	if (b_start != b_end) {
+	}
+
+	/* Replace the text in the textarea, and reflow it */
+	if (textarea_replace_text_internal(ta, b_start, b_end, rep, rep_len,
+			add_to_clipboard, byte_delta, r) == false) {
+		return false;
+	}
+
+	if (b_start == b_end && rep_len == 0) {
+		/* Nothing changed at all */
+		return true;
+	}
+
+	/* TODO: Update UNDO buffer */
+
+	return true;
+}
+
+
 /**
  * Handles the end of a drag operation
  *

desktop/textinput.h

@@ -63,6 +63,9 @@ enum input_key {
 	KEY_PAGE_DOWN,
 	KEY_DELETE_LINE_END,
 	KEY_DELETE_LINE_START,
+
+	KEY_UNDO,
+	KEY_REDO
 };
 
 

desktop/treeview.c

@@ -2078,9 +2078,13 @@ static treeview_node * treeview_get_first_selected(treeview *tree)
 /* Exported interface, documented in treeview.h */
 void treeview_get_selection(treeview *tree, void **node_data)
 {
+	treeview_node *n;
+
 	assert(tree != NULL);
 
-	*node_data = treeview_get_first_selected(tree);
+	n = treeview_get_first_selected(tree);
+
+	*node_data = n->client_data;
 }