Fix T97718: Crash using "Text on Curve"

8e4c3c6a2414 mistakenly used the `vec` argument
of `BKE_where_on_path` like it was optional. Fix by
making that argument optional too.

1 files changed, 12 insertions, 8 deletions

diff --git a/source/blender/blenkernel/intern/anim_path.c b/source/blender/blenkernel/intern/anim_path.c
index a8c25069c19..dc12519a843 100644
--- a/source/blender/blenkernel/intern/anim_path.c
+++ b/source/blender/blenkernel/intern/anim_path.c
@@ -320,18 +320,22 @@ bool BKE_where_on_path(const Object *ob,
     key_curve_position_weights(frac, w, KEY_BSPLINE);
   }
 
-  r_vec[0] = /* X */
-      w[0] * p0->vec[0] + w[1] * p1->vec[0] + w[2] * p2->vec[0] + w[3] * p3->vec[0];
-  r_vec[1] = /* Y */
-      w[0] * p0->vec[1] + w[1] * p1->vec[1] + w[2] * p2->vec[1] + w[3] * p3->vec[1];
-  r_vec[2] = /* Z */
-      w[0] * p0->vec[2] + w[1] * p1->vec[2] + w[2] * p2->vec[2] + w[3] * p3->vec[2];
+  if (r_vec) {
+    r_vec[0] = /* X */
+        w[0] * p0->vec[0] + w[1] * p1->vec[0] + w[2] * p2->vec[0] + w[3] * p3->vec[0];
+    r_vec[1] = /* Y */
+        w[0] * p0->vec[1] + w[1] * p1->vec[1] + w[2] * p2->vec[1] + w[3] * p3->vec[1];
+    r_vec[2] = /* Z */
+        w[0] * p0->vec[2] + w[1] * p1->vec[2] + w[2] * p2->vec[2] + w[3] * p3->vec[2];
+  }
 
   /* Clamp weights to 0-1 as we don't want to extrapolate other values than position. */
   clamp_v4(w, 0.0f, 1.0f);
 
-  /* Tilt, should not be needed since we have quat still used. */
-  r_vec[3] = w[0] * p0->tilt + w[1] * p1->tilt + w[2] * p2->tilt + w[3] * p3->tilt;
+  if (r_vec) {
+    /* Tilt, should not be needed since we have quat still used. */
+    r_vec[3] = w[0] * p0->tilt + w[1] * p1->tilt + w[2] * p2->tilt + w[3] * p3->tilt;
+  }
 
   if (r_quat) {
     float totfac, q1[4], q2[4];