5 files changed, 22 insertions, 14 deletions

diff --git a/source/blender/windowmanager/intern/wm.c b/source/blender/windowmanager/intern/wm.c
index 4460a1167ff..3c7a7676a63 100644
--- a/source/blender/windowmanager/intern/wm.c
+++ b/source/blender/windowmanager/intern/wm.c
@@ -369,8 +369,10 @@ void WM_check(bContext *C)
 		wm = CTX_data_main(C)->wm.first;
 		CTX_wm_manager_set(C, wm);
 	}
-	if (wm == NULL) return;
-	if (wm->windows.first == NULL) return;
+
+	if (wm == NULL || BLI_listbase_is_empty(&wm->windows)) {
+		return;
+	}
 
 	if (!G.background) {
 		/* case: fileread */
@@ -401,8 +403,10 @@ void wm_clear_default_size(bContext *C)
 		wm = CTX_data_main(C)->wm.first;
 		CTX_wm_manager_set(C, wm);
 	}
-	if (wm == NULL) return;
-	if (wm->windows.first == NULL) return;
+
+	if (wm == NULL || BLI_listbase_is_empty(&wm->windows)) {
+		return;
+	}
 	
 	for (win = wm->windows.first; win; win = win->next) {
 		win->sizex = 0;
diff --git a/source/blender/windowmanager/intern/wm_event_system.c b/source/blender/windowmanager/intern/wm_event_system.c
index b220954b5b9..b406f6f862f 100644
--- a/source/blender/windowmanager/intern/wm_event_system.c
+++ b/source/blender/windowmanager/intern/wm_event_system.c
@@ -2114,7 +2114,9 @@ static void wm_paintcursor_test(bContext *C, wmEvent *event)
 
 static void wm_event_drag_test(wmWindowManager *wm, wmWindow *win, wmEvent *event)
 {
-	if (wm->drags.first == NULL) return;
+	if (BLI_listbase_is_empty(&wm->drags)) {
+		return;
+	}
 	
 	if (event->type == MOUSEMOVE)
 		win->screen->do_draw_drag = TRUE;
diff --git a/source/blender/windowmanager/intern/wm_files.c b/source/blender/windowmanager/intern/wm_files.c
index 7bbf78ef089..03f717f0737 100644
--- a/source/blender/windowmanager/intern/wm_files.c
+++ b/source/blender/windowmanager/intern/wm_files.c
@@ -140,7 +140,7 @@ static void wm_window_match_init(bContext *C, ListBase *wmlist)
 	wmWindow *win, *active_win;
 	
 	*wmlist = G.main->wm;
-	G.main->wm.first = G.main->wm.last = NULL;
+	BLI_listbase_clear(&G.main->wm);
 	
 	active_win = CTX_wm_window(C);
 
@@ -193,7 +193,7 @@ static void wm_window_match_do(bContext *C, ListBase *oldwmlist)
 	wmWindow *oldwin, *win;
 	
 	/* cases 1 and 2 */
-	if (oldwmlist->first == NULL) {
+	if (BLI_listbase_is_empty(oldwmlist)) {
 		if (G.main->wm.first) {
 			/* nothing todo */
 		}
@@ -205,7 +205,7 @@ static void wm_window_match_do(bContext *C, ListBase *oldwmlist)
 		/* cases 3 and 4 */
 		
 		/* we've read file without wm..., keep current one entirely alive */
-		if (G.main->wm.first == NULL) {
+		if (BLI_listbase_is_empty(&G.main->wm)) {
 			bScreen *screen = NULL;
 
 			/* when loading without UI, no matching needed */
@@ -244,7 +244,7 @@ static void wm_window_match_do(bContext *C, ListBase *oldwmlist)
 			wm->defaultconf = oldwm->defaultconf;
 			wm->userconf = oldwm->userconf;
 
-			oldwm->keyconfigs.first = oldwm->keyconfigs.last = NULL;
+			BLI_listbase_clear(&oldwm->keyconfigs);
 			oldwm->addonconf = NULL;
 			oldwm->defaultconf = NULL;
 			oldwm->userconf = NULL;
@@ -588,7 +588,7 @@ int wm_homefile_read(bContext *C, ReportList *reports, bool from_memory, const c
 		if (BLI_access(startstr, R_OK) == 0) {
 			success = (BKE_read_file(C, startstr, NULL) != BKE_READ_FILE_FAIL);
 		}
-		if (U.themes.first == NULL) {
+		if (BLI_listbase_is_empty(&U.themes)) {
 			if (G.debug & G_DEBUG)
 				printf("\nNote: No (valid) '%s' found, fall back to built-in default.\n\n", startstr);
 			success = 0;
@@ -602,7 +602,9 @@ int wm_homefile_read(bContext *C, ReportList *reports, bool from_memory, const c
 
 	if (success == 0) {
 		success = BKE_read_file_from_memory(C, datatoc_startup_blend, datatoc_startup_blend_size, NULL, true);
-		if (wmbase.first == NULL) wm_clear_default_size(C);
+		if (BLI_listbase_is_empty(&wmbase)) {
+			wm_clear_default_size(C);
+		}
 		BLI_init_temporary_dir(U.tempdir);
 
 #ifdef WITH_PYTHON_SECURITY
@@ -715,7 +717,7 @@ void wm_read_history(void)
 
 	lines = BLI_file_read_as_lines(name);
 
-	G.recent_files.first = G.recent_files.last = NULL;
+	BLI_listbase_clear(&G.recent_files);
 
 	/* read list of recent opened files from recent-files.txt to memory */
 	for (l = lines, num = 0; l && (num < U.recent_files); l = l->next) {
diff --git a/source/blender/windowmanager/intern/wm_keymap.c b/source/blender/windowmanager/intern/wm_keymap.c
index c13d1dca0c4..d6ceb8caf29 100644
--- a/source/blender/windowmanager/intern/wm_keymap.c
+++ b/source/blender/windowmanager/intern/wm_keymap.c
@@ -344,7 +344,7 @@ static wmKeyMap *wm_keymap_copy(wmKeyMap *keymap)
 
 	keymapn->modal_items = keymap->modal_items;
 	keymapn->poll = keymap->poll;
-	keymapn->items.first = keymapn->items.last = NULL;
+	BLI_listbase_clear(&keymapn->items);
 	keymapn->flag &= ~(KEYMAP_UPDATE | KEYMAP_EXPANDED);
 
 	for (kmdi = keymap->diff_items.first; kmdi; kmdi = kmdi->next) {
diff --git a/source/blender/windowmanager/intern/wm_operators.c b/source/blender/windowmanager/intern/wm_operators.c
index af01cf10708..4e39394b1bc 100644
--- a/source/blender/windowmanager/intern/wm_operators.c
+++ b/source/blender/windowmanager/intern/wm_operators.c
@@ -3978,7 +3978,7 @@ static int radial_control_invoke(bContext *C, wmOperator *op, const wmEvent *eve
 	/* temporarily disable other paint cursors */
 	wm = CTX_wm_manager(C);
 	rc->orig_paintcursors = wm->paintcursors;
-	wm->paintcursors.first = wm->paintcursors.last = NULL;
+	BLI_listbase_clear(&wm->paintcursors);
 
 	/* add radial control paint cursor */
 	rc->cursor = WM_paint_cursor_activate(wm, op->type->poll,