Fix T55178: Cursor fails to restore on cancel

574c0fe38f332bd97c588029c0075ecba1fe19cd caused complications
restoring the cursor.

Use WM_cursor_modal_set/restore which is intended for operator use,
calling ED_region_cursor_set after an operator runs isn't reliable.

4 files changed, 11 insertions, 10 deletions

diff --git a/source/blender/editors/transform/transform.h b/source/blender/editors/transform/transform.h
index 2cf66794709..a8a71c95e37 100644
--- a/source/blender/editors/transform/transform.h
+++ b/source/blender/editors/transform/transform.h
@@ -601,6 +601,8 @@ typedef struct TransInfo {
 	/** #TransInfo.center has been set, don't change it. */
 #define T_OVERRIDE_CENTER	(1 << 25)
 
+#define T_MODAL_CURSOR_SET	(1 << 26)
+
 /* TransInfo->modifiers */
 #define	MOD_CONSTRAINT_SELECT	0x01
 #define	MOD_PRECISION			0x02
diff --git a/source/blender/editors/transform/transform_generics.c b/source/blender/editors/transform/transform_generics.c
index 818ac86cf0c..64f9ee58930 100644
--- a/source/blender/editors/transform/transform_generics.c
+++ b/source/blender/editors/transform/transform_generics.c
@@ -1629,6 +1629,10 @@ void postTrans(bContext *C, TransInfo *t)
 	if (t->draw_handle_cursor)
 		WM_paint_cursor_end(CTX_wm_manager(C), t->draw_handle_cursor);
 
+	if (t->flag & T_MODAL_CURSOR_SET) {
+		WM_cursor_modal_restore(CTX_wm_window(C));
+	}
+
 	/* Free all custom-data */
 	freeTransCustomDataContainer(t, NULL, &t->custom);
 	FOREACH_TRANS_DATA_CONTAINER (t, tc) {
diff --git a/source/blender/editors/transform/transform_input.c b/source/blender/editors/transform/transform_input.c
index 2004bba4f09..270ef08be50 100644
--- a/source/blender/editors/transform/transform_input.c
+++ b/source/blender/editors/transform/transform_input.c
@@ -351,7 +351,8 @@ void initMouseInputMode(TransInfo *t, MouseInput *mi, MouseInputMode mode)
 		case HLP_NONE:
 			/* INPUT_VECTOR, INPUT_CUSTOM_RATIO, INPUT_CUSTOM_RATIO_FLIP */
 			if (t->flag & T_MODAL) {
-				WM_cursor_set(win, BC_NSEW_SCROLLCURSOR);
+				t->flag |= T_MODAL_CURSOR_SET;
+				WM_cursor_modal_set(win, BC_NSEW_SCROLLCURSOR);
 			}
 			break;
 		case HLP_SPRING:
@@ -360,7 +361,8 @@ void initMouseInputMode(TransInfo *t, MouseInput *mi, MouseInputMode mode)
 		case HLP_HARROW:
 		case HLP_VARROW:
 			if (t->flag & T_MODAL) {
-				WM_cursor_set(win, CURSOR_NONE);
+				t->flag |= T_MODAL_CURSOR_SET;
+				WM_cursor_modal_set(win, CURSOR_NONE);
 			}
 			break;
 		default:
diff --git a/source/blender/windowmanager/intern/wm_event_system.c b/source/blender/windowmanager/intern/wm_event_system.c
index 4f3f8ece1f0..c800370a85d 100644
--- a/source/blender/windowmanager/intern/wm_event_system.c
+++ b/source/blender/windowmanager/intern/wm_event_system.c
@@ -1958,14 +1958,7 @@ static int wm_handler_operator_call(bContext *C, ListBase *handlers, wmEventHand
 
 				/* remove modal handler, operator itself should have been canceled and freed */
 				if (retval & (OPERATOR_CANCELLED | OPERATOR_FINISHED)) {
-					/* set cursor back to the default for the region */
-					wmWindow *win = CTX_wm_window(C);
-					WM_cursor_grab_disable(win, NULL);
-					/* Causes crash when joining areas: T55166, seems this is not even needed. */
-#if 0
-					ED_region_cursor_set(win, area, region);
-#endif
-
+					WM_cursor_grab_disable(CTX_wm_window(C), NULL);
 
 					BLI_remlink(handlers, handler);
 					wm_event_free_handler(handler);