Fix for #35373, calling any paint operator from operator search menu

with mouse crashes blender.

Issue here is that paint operator invocation, immediately calls modal,
which checks if event is the same as initialization event plus keyup.
Since using the mouse on amenu calls the operator on mouse button up,
the operator ended immediately and that cause immediate cleanup and
crash,

Worked around this by forbidding the operator to finish on first modal
call (which is expected by all the asserts on invoke anyway). This
prevents the crash but requires an extra up event to end.

Also, ported part of Jason Wilkins' patch to stroke code to allow for
stroke sampling to be done before a dab is first performed and as soon
as the stroke begins

1 files changed, 23 insertions, 17 deletions

diff --git a/source/blender/editors/sculpt_paint/paint_stroke.c b/source/blender/editors/sculpt_paint/paint_stroke.c
index 2c2ed40b403..9d727dc689f 100644
--- a/source/blender/editors/sculpt_paint/paint_stroke.c
+++ b/source/blender/editors/sculpt_paint/paint_stroke.c
@@ -90,7 +90,9 @@ typedef struct PaintStroke {
 	int stroke_started;
 	/* event that started stroke, for modal() return */
 	int event_type;
-	
+	/* check if stroke variables have been initialized */
+	bool stroke_init;
+	/* check if various brush mapping variables have been initialized */
 	bool brush_init;
 	float initial_mouse[2];
 	/* cached_pressure stores initial pressure for size pressure influence mainly */
@@ -654,7 +656,8 @@ int paint_stroke_modal(bContext *C, wmOperator *op, const wmEvent *event)
 	PaintStroke *stroke = op->customdata;
 	PaintSample sample_average;
 	float mouse[2];
-	int first = 0;
+	bool first_dab = false;
+	bool first_modal = false;
 	float zoomx, zoomy;
 	bool redraw = false;
 	float pressure;
@@ -675,23 +678,28 @@ int paint_stroke_modal(bContext *C, wmOperator *op, const wmEvent *event)
 	if (event->type == NDOF_MOTION)
 		return OPERATOR_PASS_THROUGH;
 
+	/* one time initialization */
+	if(!stroke->stroke_init) {
+		stroke->smooth_stroke_cursor =
+			    WM_paint_cursor_activate(CTX_wm_manager(C), paint_poll, paint_draw_smooth_stroke, stroke);
+
+		stroke->stroke_init = true;
+		first_modal = true;
+	}
+
+	/* one time stroke initialization */
 	if (!stroke->stroke_started) {
-		copy_v2_v2(stroke->last_mouse_position, sample_average.mouse);
 		stroke->last_pressure = sample_average.pressure;
+		copy_v2_v2(stroke->last_mouse_position, sample_average.mouse);
 		stroke->stroke_started = stroke->test_start(C, op, sample_average.mouse);
 		BLI_assert((stroke->stroke_started & ~1) == 0);  /* 0/1 */
-		stroke->last_pressure = pressure;
 
 		if (stroke->stroke_started) {
-			stroke->smooth_stroke_cursor =
-			    WM_paint_cursor_activate(CTX_wm_manager(C), paint_poll, paint_draw_smooth_stroke, stroke);
-
 			if (stroke->brush->flag & BRUSH_AIRBRUSH)
 				stroke->timer = WM_event_add_timer(CTX_wm_manager(C), CTX_wm_window(C), TIMER, stroke->brush->rate);
-		}
 
-		first = 1;
-		//ED_region_tag_redraw(ar);
+			first_dab = true;
+		}
 	}
 
 	/* Cancel */
@@ -702,16 +710,15 @@ int paint_stroke_modal(bContext *C, wmOperator *op, const wmEvent *event)
 			return paint_stroke_cancel(C, op);
 	}
 
-	if (event->type == stroke->event_type && event->val == KM_RELEASE) {
+	if (event->type == stroke->event_type && event->val == KM_RELEASE && !first_modal) {
 		stroke_done(C, op);
 		return OPERATOR_FINISHED;
 	}
-	else if ((first) ||
-	         (ELEM(event->type, MOUSEMOVE, INBETWEEN_MOUSEMOVE)) ||
+	else if (first_modal || (ELEM(event->type, MOUSEMOVE, INBETWEEN_MOUSEMOVE)) ||
 	         (event->type == TIMER && (event->customdata == stroke->timer)) )
 	{
-		if (stroke->stroke_started) {
-			if (paint_smooth_stroke(stroke, mouse, &pressure, &sample_average, mode)) {
+		if (paint_smooth_stroke(stroke, mouse, &pressure, &sample_average, mode)) {
+			if (stroke->stroke_started) {
 				if (paint_space_stroke_enabled(stroke->brush, mode)) {
 					if (paint_space_stroke(C, op, mouse, pressure))
 						redraw = true;
@@ -726,8 +733,7 @@ int paint_stroke_modal(bContext *C, wmOperator *op, const wmEvent *event)
 
 	/* we want the stroke to have the first daub at the start location
 	 * instead of waiting till we have moved the space distance */
-	if (first &&
-	    stroke->stroke_started &&
+	if (first_dab &&
 	    paint_space_stroke_enabled(stroke->brush, mode) &&
 	    !(stroke->brush->flag & BRUSH_ANCHORED) &&
 	    !(stroke->brush->flag & BRUSH_SMOOTH_STROKE))