Better, cleaner error handling.

cmd/wmii/client.c

@@ -159,7 +159,6 @@ client_create(XWindow w, XWindowAttributes *wa) {
 
 	p.x = def.border;
 	p.y = labelh(def.font);
-	reparentwindow(&c->w, c->framewin, p);
 
 	group_init(c);
 
@@ -172,6 +171,20 @@ client_create(XWindow w, XWindowAttributes *wa) {
 			break;
 		}
 
+
+	/* 
+	 * It's actually possible for a window to be destroyed
+	 * before we get a chance to reparant it. Check for that
+	 * now, because otherwise we'll wind up mapping an empty
+	 * frame.
+	 */
+	traperrors(true);
+	reparentwindow(&c->w, c->framewin, p);
+	if(traperrors(false)) {
+		client_destroy(c);
+		return nil;
+	}
+
 	ewmh_initclient(c);
 
 	event("CreateClient %C\n", c);
@@ -181,7 +194,7 @@ client_create(XWindow w, XWindowAttributes *wa) {
 
 void
 client_manage(Client *c) {
-	Client *trans;
+	Client *leader;
 	Frame *f;
 	char *tags;
 
@@ -192,14 +205,14 @@ client_manage(Client *c) {
 
 	tags = getprop_string(&c->w, "_WMII_TAGS");
 
-	trans = win2client(c->trans);
-	if(trans == nil && c->group)
-		trans = group_leader(c->group);
+	leader = win2client(c->trans);
+	if(leader == nil && c->group)
+		leader = group_leader(c->group);
 
-	if(tags && (!trans || starting))
+	if(tags && (!leader || leader == c || starting))
 		utflcpy(c->tags, tags, sizeof c->tags);
-	else if(trans)
-		utflcpy(c->tags, trans->tags, sizeof c->tags);
+	else if(leader)
+		utflcpy(c->tags, leader->tags, sizeof c->tags);
 	free(tags);
 
 	if(!c->tags[0])
@@ -231,15 +244,8 @@ client_manage(Client *c) {
 	}
 }
 
-static int /* Temporary Xlib error handler */
-ignoreerrors(Display *d, XErrorEvent *e) {
-	USED(d, e);
-	return 0;
-}
-
 void
 client_destroy(Client *c) {
-	int (*handler)(Display*, XErrorEvent*);
 	Rectangle r;
 	char *none;
 	Client **tc;
@@ -261,8 +267,9 @@ client_destroy(Client *c) {
 		hide = true;
 
 	XGrabServer(display);
+
 	/* In case the client is already destroyed. */
-	handler = XSetErrorHandler(ignoreerrors);
+	traperrors(true);
 
 	sethandler(&c->w, nil);
 	if(hide)
@@ -270,8 +277,7 @@ client_destroy(Client *c) {
 	else
 		reparentwindow(&c->w, &scr.root, r.min);
 
-	sync();
-	XSetErrorHandler(handler);
+	traperrors(false);
 	XUngrabServer(display);
 
 	none = nil;

cmd/wmii/layout.c

@@ -235,10 +235,15 @@ static void
 trampoline(int fn, Frame *f) {
 
 	while(fn > 0) {
+		resizing = fn != TFloat;
+		view_update(f->view);
+		warppointer(grabboxcenter(f));
 		//f->collapsed = false;
 		fn = tramp[fn](f);
 	}
 	ungrabpointer();
+	resizing = false;
+	view_update(f->view);
 }
 
 void
@@ -255,17 +260,11 @@ mouse_movegrabbox(Client *c, bool grabmod) {
 		y = (float)p.y / Dy(f->r);
 	}
 
-	resizing = true;
-	view_update(f->view);
-	warppointer(grabboxcenter(f));
-
 	if(f->area->floating)
 		trampoline(TFloat, f);
 	else
 		trampoline(THCol, f);
 
-	resizing = false;
-	view_update(f->view);
 	if(grabmod)
 		warppointer(addpt(f->r.min, Pt(x * Dx(f->r),
 					       y * Dy(f->r))));

cmd/wmii/main.c

@@ -17,10 +17,8 @@
 static const char
 	version[] = "wmii-"VERSION", ©2008 Kris Maglione\n";
 
-static int (*xlib_errorhandler) (Display*, XErrorEvent*);
 static char*	address;
 static char*	ns_path;
-static bool	check_other_wm;
 static int	sleeperfd;
 static int	sock;
 static int	exitsignal;
@@ -136,6 +134,23 @@ init_cursors(void) {
 	XFreePixmap(display, pix);
 }
 
+/*
+ * There's no way to check accesses to destroyed windows, thus
+ * those cases are ignored (especially on UnmapNotifies).
+ * Other types of errors call Xlib's default error handler, which
+ * calls exit().
+ */
+ErrorCode ignored_xerrors[] = {
+	{ 0, BadWindow },
+	{ X_SetInputFocus, BadMatch },
+	{ X_PolyText8, BadDrawable },
+	{ X_PolyFillRectangle, BadDrawable },
+	{ X_PolySegment, BadDrawable },
+	{ X_ConfigureWindow, BadMatch },
+	{ X_GrabKey, BadAccess },
+	{ X_GetAtomName, BadAtom },
+};
+
 void
 init_screen(WMScreen *screen) {
 
@@ -157,51 +172,6 @@ cleanup(void) {
 	close(sleeperfd);
 }
 
-/*
- * There's no way to check accesses to destroyed windows, thus
- * those cases are ignored (especially on UnmapNotifies).
- * Other types of errors call Xlib's default error handler, which
- * calls exit().
- */
-static int
-errorhandler(Display *dpy, XErrorEvent *error) {
-	static struct {
-		uchar rcode, ecode;
-	} itab[] = {
-		{ 0, BadWindow },
-		{ X_SetInputFocus, BadMatch },
-		{ X_PolyText8, BadDrawable },
-		{ X_PolyFillRectangle, BadDrawable },
-		{ X_PolySegment, BadDrawable },
-		{ X_ConfigureWindow, BadMatch },
-		{ X_GrabKey, BadAccess },
-		{ X_GetAtomName, BadAtom },
-	};
-	static int dead;
-	int i;
-
-	USED(dpy);
-
-	if(check_other_wm)
-		fatal("another window manager is already running");
-
-	for(i = 0; i < nelem(itab); i++)
-		if((itab[i].rcode == 0 || itab[i].rcode == error->request_code)
-		&& (itab[i].ecode == 0 || itab[i].ecode == error->error_code))
-			return 0;
-
-	fprint(2, "%s: fatal error: Xrequest code=%d, Xerror code=%d\n",
-			argv0, error->request_code, error->error_code);
-
-	/* Try to cleanup, but only try once, in case we're called recursively. */
-	USED(dead);
-#ifdef notdef
-	if(!dead++)
-		cleanup();
-#endif
-	return xlib_errorhandler(display, error); /* calls exit() */
-}
-
 static void
 cleanup_handler(int signal) {
 	sa.sa_handler = SIG_DFL;
@@ -338,14 +308,12 @@ extern int fmtevent(Fmt*);
 
 	initdisplay();
 
-	xlib_errorhandler = XSetErrorHandler(errorhandler);
-
-	check_other_wm = true;
+	traperrors(true);
 	selectinput(&scr.root, SubstructureRedirectMask
 			     | EnterWindowMask);
 	sync();
-
-	check_other_wm = false;
+	if(traperrors(false))
+		fatal("another window manager is already running");
 
 	passwd = getpwuid(getuid());
 	user = estrdup(passwd->pw_name);

cmd/wmii/view.c

@@ -252,10 +252,11 @@ view_update(View *v) {
 
 	for(c=client; c; c=c->next) {
 		f = c->sel;
-		if(f && f->view == v
-		&& !(f->area && f->area->max && f->area->floating && f->area != v->sel))
-			client_resize(c, f->r);
-		else {
+		if((f && f->view == v)
+		&& (f->area == v->sel || !(f->area && f->area->max && f->area->floating))) {
+			if(f->area)
+				client_resize(c, f->r);
+		}else {
 			unmap_frame(c);
 			client_unmap(c, IconicState);
 		}
@@ -304,8 +305,11 @@ view_attach(View *v, Frame *f) {
 	
 	c = f->client;
 
-	oldsel = nil;
+	oldsel = v->oldsel;
 	a = v->sel;
+	print("view: %s\n", v->name);
+	print("client: %C\n", c);
+	print("< sel: %a\n", v->sel);
 	if(client_floats_p(c)) {
 		if(v->sel != v->area)
 			oldsel = v->sel;
@@ -323,6 +327,7 @@ view_attach(View *v, Frame *f) {
 		else if(starting || c->sel && c->sel->area && !c->sel->area->floating)
 			a = v->area->next;
 	}
+	print("< sel: %a oldsel: %a\n", v->sel, oldsel);
 
 	area_attach(a, f);
 	/* TODO: Decide whether to focus this frame */
@@ -341,6 +346,7 @@ view_attach(View *v, Frame *f) {
 
 	if(oldsel)
 		v->oldsel = oldsel;
+	print("< sel: %a oldsel: %a\n", v->sel, oldsel);
 
 	if(c->sel == nil)
 		c->sel = f;

cmd/wmii/x11.c

@@ -27,6 +27,9 @@ static Map	atommap;
 static MapEnt*	wbucket[137];
 static MapEnt*	abucket[137];
 
+static int	errorhandler(Display*, XErrorEvent*);
+static int	(*xlib_errorhandler) (Display*, XErrorEvent*);
+
 
 /* Rectangles/Points */
 XRectangle
@@ -185,6 +188,46 @@ initdisplay(void) {
 	fmtinstall('R', Rfmt);
 	fmtinstall('P', Pfmt);
 	fmtinstall('W', Wfmt);
+
+	xlib_errorhandler = XSetErrorHandler(errorhandler);
+}
+
+/* Error handling */
+
+ErrorCode ignored_xerrors[];
+static bool	_trap_errors;
+static long	nerrors;
+
+static int
+errorhandler(Display *dpy, XErrorEvent *error) {
+	ErrorCode *e;
+
+	USED(dpy);
+
+	if(_trap_errors)
+		nerrors++;
+
+	e = ignored_xerrors;
+	if(e)
+	for(; e->rcode || e->ecode; e++)
+		if((e->rcode == 0 || e->rcode == error->request_code)
+		&& (e->ecode == 0 || e->ecode == error->error_code))
+			return 0;
+
+	fprint(2, "%s: fatal error: Xrequest code=%d, Xerror code=%d\n",
+			argv0, error->request_code, error->error_code);
+	return xlib_errorhandler(display, error); /* calls exit() */
+}
+
+int
+traperrors(bool enable) {
+	
+	sync();
+	_trap_errors = enable;
+	if (enable)
+		nerrors = 0;
+	return nerrors;
+	
 }
 
 /* Images */

include/x11.h

@@ -48,6 +48,7 @@ struct Rectangle {
 };
 
 typedef struct CTuple CTuple;
+typedef struct ErrorCode ErrorCode;
 typedef struct Ewmh Ewmh;
 typedef struct Font Font;
 typedef struct Handlers Handlers;
@@ -63,6 +64,11 @@ struct CTuple {
 	char colstr[24]; /* #RRGGBB #RRGGBB #RRGGBB */
 };
 
+struct ErrorCode {
+	uchar rcode;
+	uchar ecode;
+};
+
 struct Ewmh {
 	long	type;
 	long	ping;
@@ -234,6 +240,7 @@ Point	subpt(Point, Point);
 void	sync(void);
 uint	textwidth(Font*, char*);
 uint	textwidth_l(Font*, char*, uint len);
+int	traperrors(bool);
 Point	translate(Window*, Window*, Point);
 void	ungrabpointer(void);
 int	unmapwin(Window*);