feh_reload_image: Fix regression of old caching issue (closes #63)

This was broken by the changes allowing --reload to retry ad infinitum.

Now force_new is used to decide whether or not to work around the Imlib2
caching issue.  Because of this, a few feh_reload_image calls needed to be
changed.

src/events.c

@@ -114,7 +114,7 @@ static void feh_event_handle_ButtonPress(XEvent * ev)
 				- winwid->im_y) / winwid->old_zoom;
 	} else if (ev->xbutton.button == opt.reload_button) {
 		D(("Reload Button Press event\n"));
-			feh_reload_image(winwid, 0, 0);
+			feh_reload_image(winwid, 0, 1);
 	} else if (ev->xbutton.button == opt.prev_button) {
 		D(("Prev Button Press event\n"));
 		if (winwid->type == WIN_TYPE_SLIDESHOW)

src/menu.c

@@ -1302,7 +1302,7 @@ void feh_menu_cb(feh_menu * m, feh_menu_item * i, int action, void *data)
 			winwidget_render_image(m->fehwin, 1, 0);
 			break;
 		case CB_RELOAD:
-			feh_reload_image(m->fehwin, 0, 0);
+			feh_reload_image(m->fehwin, 0, 1);
 			break;
 		case CB_REMOVE:
 			feh_filelist_image_remove(m->fehwin, 0);

src/slideshow.c

@@ -171,11 +171,19 @@ void feh_reload_image(winwidget w, int resize, int force_new)
 	old_w = gib_imlib_image_get_width(w->im);
 	old_h = gib_imlib_image_get_height(w->im);
 
-	/* if the image has changed in dimensions - we gotta resize */
+	/*
+	 * If we don't free the old image before loading the new one, Imlib2's
+	 * caching will get in our way.
+	 * However, if --reload is used (force_new == 0), we want to continue if
+	 * the new image cannot be loaded, so we must not free the old image yet.
+	 */
+	if (force_new)
+		winwidget_free_image(w);
+
 	if ((feh_load_image(&tmp, FEH_FILE(w->file->data))) == 0) {
-		if (force_new) {
+		if (force_new)
 			eprintf("failed to reload image\n");
-		} else {
+		else {
 			im_weprintf(w, "Couldn't reload image. Is it still there?");
 			winwidget_render_image(w, 0, 0);
 		}
@@ -189,8 +197,8 @@ void feh_reload_image(winwidget w, int resize, int force_new)
 			(old_h != gib_imlib_image_get_height(tmp))))
 		resize = 1;
 
-	/* force imlib2 not to cache */
-	winwidget_free_image(w);
+	if (!force_new)
+		winwidget_free_image(w);
 
 	w->im = tmp;
 	winwidget_reset_image(w);

src/thumbnail.c

@@ -922,7 +922,7 @@ void feh_thumbnail_show_fullsize(feh_file *thumbfile)
 		free(thumbwin->file);
 		thumbwin->file = gib_list_add_front(NULL, thumbfile);
 		winwidget_rename(thumbwin, s);
-		feh_reload_image(thumbwin, 1, 0);
+		feh_reload_image(thumbwin, 1, 1);
 	}
 }