Fixed crash on loss of window data stored in deallocated client.

client.c

@@ -82,9 +82,20 @@ static void set_state_not_focused(struct JBWMClient * restrict c)
 	jbwm_ewmh_remove_state(c->d, c->window, jbwm_ewmh_get_atom(
 		JBWM_EWMH_WM_STATE_FOCUSED));
 }
+static bool check_current(void)
+{
+	if (jbwm_client_data.current) {
+		if (!jbwm_client_data.current->d) {
+			jbwm_client_data.current = NULL;
+			return false;
+		}
+		return true;
+	}
+	return false;
+}
 static void unselect_current(void)
 {
-	if(jbwm_client_data.current)
+	if (check_current())
 		set_state_not_focused(jbwm_client_data.current);
 }
 static void set_border(struct JBWMClient * restrict c)
@@ -104,9 +115,14 @@ static void set_focused(struct JBWMClient * c)
 static void set_active_window(struct JBWMClient * c)
 {
 	unselect_current(); // depends on jbwm_client_data.current
+	/* Store the window id as a static variable here in case
+	 * client c is freed.  If the property is read after the
+	 * client is freed, it will cause a segmentation fault.  */
+	static jbwm_window_t w;
+	w = c->window;
 	jbwm_set_property(c->d, jbwm_get_root(c),
 		jbwm_ewmh_get_atom(JBWM_EWMH_ACTIVE_WINDOW),
-		XA_WINDOW, &(c->parent), 1);
+		XA_WINDOW, &w, 1);
 	jbwm_client_data.current = c;
 }
 void jbwm_select_client(struct JBWMClient * c)

events.c

@@ -135,7 +135,7 @@ void jbwm_event_loop(Display * restrict d)
 		case MappingNotify:
 		case MotionNotify:
 			// ignore
-			break;
+			continue;
 		case ConfigureNotify:
 			JBWM_LOG("ConfigureNotify");
 			/* Failure to do this causes Java Swing
@@ -162,15 +162,16 @@ void jbwm_event_loop(Display * restrict d)
 			/* Sometimes, we were getting a client with a
 			 * NULL display pointer within, check for this
 			 * before going any further.  */
-			if(c && (ev.xcrossing.window == c->parent) &&
-				c->d) 
+			JBWM_LOG("\t\t\tEnterNotify: xc.detail: %d",
+				ev.xcrossing.detail);
+			if (c && c->d && ev.xcrossing.window == c->parent)
 				jbwm_select_client(c);
-			break;
+			continue;
 #ifdef JBWM_USE_TITLE_BAR
 		case Expose:
 			if (c && !ev.xexpose.count)
 				jbwm_update_title_bar(c);
-			break;
+			continue;
 #endif//JBWM_USE_TITLE_BAR
 #ifdef JBWM_USE_EWMH
 		case CreateNotify:
@@ -210,7 +211,7 @@ void jbwm_event_loop(Display * restrict d)
 				XInstallColormap(ev.xcolormap.display,
 					c->cmap);
 			}
-			break;
+			continue;
 #ifdef JBWM_USE_EWMH
 		case ClientMessage:
 			jbwm_ewmh_handle_client_message(&ev.xclient, c);

typedef.h

@@ -3,10 +3,10 @@
 #define JBWM_TYPEDEF_H
 #include <stdint.h>
 #include <X11/Xlib.h>
-typedef uint32_t jbwm_window_t;
+typedef Window jbwm_window_t;
 typedef uint32_t jbwm_pixel_t;
-typedef uint32_t jbwm_cmap_t;
-typedef uint32_t jbwm_atom_t;
+typedef Colormap jbwm_cmap_t;
+typedef Atom jbwm_atom_t;
 typedef uint16_t jbwm_length_t;
 typedef int16_t jbwm_axis_t;
 #endif//!JBWM_TYPEDEF_H

util.c

@@ -7,11 +7,13 @@
 #include <stdbool.h>
 void jbwm_set_property(Display * restrict d, const jbwm_window_t win,
 	const jbwm_atom_t property, const jbwm_atom_t type,
-	void * restrict data, int16_t size)
+	void * restrict data, uint16_t size)
 {
-	if (d)
-		XChangeProperty(d, win, property, type,
-			32, PropModeReplace, data, size);
+	if (!d)
+		return;
+	XChangeProperty(d, win, property, type, 32, PropModeReplace,
+		data, size);
+	XFlush(d);
 }
 jbwm_pixel_t jbwm_get_pixel(Display * restrict dpy,
 	const uint8_t screen, const char * restrict name)

util.h

@@ -7,7 +7,7 @@
 #include "typedef.h"
 void jbwm_set_property(Display * restrict d, const jbwm_window_t win,
 	const jbwm_atom_t property, const jbwm_atom_t type,
-	void * restrict data, int16_t size);
+	void * restrict data, uint16_t size);
 jbwm_pixel_t jbwm_get_pixel(Display * restrict d, const uint8_t screen,
 	const char * restrict name);
 // Free the result with XFree