Fix #35683: Addon working fine in console. But crashed when click GUI button.

Crash happened in ED_view3d_calc_zfac and happend in cases operator was invoked
from a region different from RGN_TYPE_WINDOW.

For a transformation zfac is only used in convertViewVec in cases region is
RGN_TYPE_WINDOW, so solved by just adding extra check in calculateCenter
for this particular case.

1 files changed, 13 insertions, 1 deletions

diff --git a/source/blender/editors/transform/transform_generics.c b/source/blender/editors/transform/transform_generics.c
index a2957263ba9..6b0139aa8d9 100644
--- a/source/blender/editors/transform/transform_generics.c
+++ b/source/blender/editors/transform/transform_generics.c
@@ -1711,7 +1711,19 @@ void calculateCenter(TransInfo *t)
 		else {
 			copy_v3_v3(vec, t->center);
 		}
-		t->zfac = ED_view3d_calc_zfac(t->ar->regiondata, vec, NULL);
+
+		/* zfac is only used convertViewVec only in cases operator was invoked in RGN_TYPE_WINDOW
+		 * and never used in other cases.
+		 *
+		 * We need special case here as well, since ED_view3d_calc_zfac will crahs when called
+		 * for a region different from RGN_TYPE_WINDOW.
+		 */
+		if (t->ar->regiontype == RGN_TYPE_WINDOW) {
+			t->zfac = ED_view3d_calc_zfac(t->ar->regiondata, vec, NULL);
+		}
+		else {
+			t->zfac = 0.0f;
+		}
 	}
 }