[Bf-blender-cvs] [ffddf9e5c91] blender-v3.0-release: Fix T93338: Curve Guide force field crash

[Philipp Oeser]

Commit: ffddf9e5c9175d25078ca441b21e5eb478ecd106
Author: Philipp Oeser
Date:   Thu Nov 25 13:45:32 2021 +0100
Branches: blender-v3.0-release
https://developer.blender.org/rBffddf9e5c9175d25078ca441b21e5eb478ecd106

Fix T93338: Curve Guide force field crash

Caused by {rBcf2baa585cc8}.

For Curve Guide force fields to work, the `Path Animation` option has to
be enabled. With it disabled, we are lacking the necessary
`anim_path_accum_length` data initialized [done by
`BKE_anim_path_calc_data`] which `BKE_where_on_path` relies on since
above commit.

Now just check for this before using it - and return early otherwise.
Prior to said commit, `BKE_where_on_path` would equally return early
with a similar message, so that is expected behavior here.

Maniphest Tasks: T93338

Differential Revision: https://developer.blender.org/D13371

===================================================================

M	source/blender/blenkernel/intern/anim_path.c

===================================================================

diff --git a/source/blender/blenkernel/intern/anim_path.c b/source/blender/blenkernel/intern/anim_path.c
index de470a15041..ff94a04e75e 100644
--- a/source/blender/blenkernel/intern/anim_path.c
+++ b/source/blender/blenkernel/intern/anim_path.c
@@ -254,6 +254,10 @@ bool BKE_where_on_path(const Object *ob,
     CLOG_WARN(&LOG, "No curve cache!");
     return false;
   }
+  if (ob->runtime.curve_cache->anim_path_accum_length == NULL) {
+    CLOG_WARN(&LOG, "No anim path!");
+    return false;
+  }
   /* We only use the first curve. */
   BevList *bl = ob->runtime.curve_cache->bev.first;
   if (bl == NULL || !bl->nr) {