Fix T79712: Color Changes do not record in Auto-Key Mode

Caused by rBfffba2b6530.

In above commit, the buttons rnaindex [-1 for entire arrays like colors]
was not used anymore for the entire function body of
`ED_autokeyframe_property` (previously in `ui_but_anim_autokey`).
Replacing the index with 0 (in the array case) is indeed necessary for
`BKE_fcurve_find_by_rna_context_ui`, prior to rBfffba2b6530 this was
taken care of by using `ui_but_get_fcurve` instead [which did this
internally].

But using an index of 0 (instead of -1) for the entire function body of
`ED_autokeyframe_property` fails for the array part later, namely
`insert_keyframe` needs -1 here.
Now just replace the index for //finding the FCurve//, but use the
original for //inserting the keyframe//.

Could be backported to 2.83 LTS.

Reviewers: campbellbarton, sybren

Subscribers:

1 files changed, 4 insertions, 1 deletions

diff --git a/source/blender/editors/animation/keyframing.c b/source/blender/editors/animation/keyframing.c
index 8c2f4216aa9..66d4882cf9d 100644
--- a/source/blender/editors/animation/keyframing.c
+++ b/source/blender/editors/animation/keyframing.c
@@ -3025,8 +3025,11 @@ bool ED_autokeyframe_property(
   bool special;
   bool changed = false;
 
+  /* for entire array buttons we check the first component, it's not perfect
+   * but works well enough in typical cases */
+  const int rnaindex_check = (rnaindex == -1) ? 0 : rnaindex;
   fcu = BKE_fcurve_find_by_rna_context_ui(
-      C, ptr, prop, rnaindex, NULL, &action, &driven, &special);
+      C, ptr, prop, rnaindex_check, NULL, &action, &driven, &special);
 
   if (fcu == NULL) {
     return changed;