Fix #27328: Undoing an operation while baking fluids freezes Blender

Prevent Undo be run if there are any jobs are currently running.
This also makes sense with such jobs as multires baker, for example.

3 files changed, 18 insertions, 0 deletions

diff --git a/source/blender/editors/util/undo.c b/source/blender/editors/util/undo.c
index 527537b5efb..f0055bd6008 100644
--- a/source/blender/editors/util/undo.c
+++ b/source/blender/editors/util/undo.c
@@ -125,6 +125,12 @@ static int ed_undo_step(bContext *C, int step, const char *undoname)
 	Object *obact= CTX_data_active_object(C);
 	ScrArea *sa= CTX_wm_area(C);
 
+	/* undo during jobs are running can easily lead to freeing data using by jobs,
+	    or they can just lead to freezing job in some other cases */
+	if(WM_jobs_has_running(CTX_wm_manager(C))) {
+		return OPERATOR_CANCELLED;
+	}
+
 	/* grease pencil can be can be used in plenty of spaces, so check it first */
 	if(ED_gpencil_session_active()) {
 		return ED_undo_gpencil_step(C, step, undoname);
diff --git a/source/blender/windowmanager/WM_api.h b/source/blender/windowmanager/WM_api.h
index fcdb6d25083..1d8161086b0 100644
--- a/source/blender/windowmanager/WM_api.h
+++ b/source/blender/windowmanager/WM_api.h
@@ -316,6 +316,8 @@ void		WM_jobs_stop(struct wmWindowManager *wm, void *owner, void *startjob);
 void		WM_jobs_kill(struct wmWindowManager *wm, void *owner, void (*)(void *, short int *, short int *, float *));
 void		WM_jobs_stop_all(struct wmWindowManager *wm);
 
+int			WM_jobs_has_running(struct wmWindowManager *wm);
+
 			/* clipboard */
 char		*WM_clipboard_text_get(int selection);
 void		WM_clipboard_text_set(char *buf, int selection);
diff --git a/source/blender/windowmanager/intern/wm_jobs.c b/source/blender/windowmanager/intern/wm_jobs.c
index 16691ac5ab0..2d0d0f92a44 100644
--- a/source/blender/windowmanager/intern/wm_jobs.c
+++ b/source/blender/windowmanager/intern/wm_jobs.c
@@ -505,3 +505,13 @@ void wm_jobs_timer(const bContext *C, wmWindowManager *wm, wmTimer *wt)
 	}
 }
 
+int WM_jobs_has_running(wmWindowManager *wm)
+{
+	wmJob *steve;
+
+	for(steve= wm->jobs.first; steve; steve= steve->next)
+		if(steve->running)
+			return 1;
+
+	return 0;
+}