[Bf-blender-cvs] [ee486aa5ce0] blender-v2.93-release: Fix T83164: Spline IK `joint_bindings` parameter is broken.

[Bastien Montagne]

Commit: ee486aa5ce08fb344fba5cdbb25e017854d67bf4
Author: Bastien Montagne
Date:   Thu Aug 5 17:17:15 2021 +0200
Branches: blender-v2.93-release
https://developer.blender.org/rBee486aa5ce08fb344fba5cdbb25e017854d67bf4

Fix T83164: Spline IK `joint_bindings` parameter is broken.

Code freeing the array would not properly reset its length value to
zero.

Note that this corrupted data could also be saved in .blend files, so
had to bump fileversion and add some doversion code too.

Fix T90166: crash when creating a liboverride.

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

M	source/blender/blenkernel/intern/constraint.c
M	source/blender/blenloader/intern/versioning_290.c
M	source/blender/editors/object/object_constraint.c

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

diff --git a/source/blender/blenkernel/intern/constraint.c b/source/blender/blenkernel/intern/constraint.c
index bb785d310b9..f8d0166b3ca 100644
--- a/source/blender/blenkernel/intern/constraint.c
+++ b/source/blender/blenkernel/intern/constraint.c
@@ -4504,9 +4504,7 @@ static void splineik_free(bConstraint *con)
   bSplineIKConstraint *data = con->data;
 
   /* binding array */
-  if (data->points) {
-    MEM_freeN(data->points);
-  }
+  MEM_SAFE_FREE(data->points);
 }
 
 static void splineik_copy(bConstraint *con, bConstraint *srccon)
diff --git a/source/blender/blenloader/intern/versioning_290.c b/source/blender/blenloader/intern/versioning_290.c
index 7a872ff31b7..c46cdf1c247 100644
--- a/source/blender/blenloader/intern/versioning_290.c
+++ b/source/blender/blenloader/intern/versioning_290.c
@@ -881,6 +881,19 @@ static ARegion *do_versions_add_region_if_not_found(ListBase *regionbase,
   return new_region;
 }
 
+static void do_version_constraints_spline_ik_joint_bindings(ListBase *lb)
+{
+  /* Binding array data could be freed without properly resetting its size data. */
+  LISTBASE_FOREACH (bConstraint *, con, lb) {
+    if (con->type == CONSTRAINT_TYPE_SPLINEIK) {
+      bSplineIKConstraint *data = (bSplineIKConstraint *)con->data;
+      if (data->points == NULL) {
+        data->numpoints = 0;
+      }
+    }
+  }
+}
+
 /* NOLINTNEXTLINE: readability-function-size */
 void blo_do_versions_290(FileData *fd, Library *UNUSED(lib), Main *bmain)
 {
@@ -1086,7 +1099,6 @@ void blo_do_versions_290(FileData *fd, Library *UNUSED(lib), Main *bmain)
       }
     }
   }
-
   if (!MAIN_VERSION_ATLEAST(bmain, 291, 1)) {
 
     /* Initialize additional parameter of the Nishita sky model and change altitude unit. */
@@ -2090,6 +2102,17 @@ void blo_do_versions_290(FileData *fd, Library *UNUSED(lib), Main *bmain)
   if (!MAIN_VERSION_ATLEAST(bmain, 300, 20)) {
     ListBase *lb = which_libbase(bmain, ID_VF);
     BKE_main_id_repair_duplicate_names_listbase(lb);
+
+    /* Fix SplineIK constraint's inconsistency between binding points array and its stored size. */
+    LISTBASE_FOREACH (Object *, ob, &bmain->objects) {
+      /* NOTE: Objects should never have SplineIK constraint, so no need to apply this fix on
+       * their constraints. */
+      if (ob->pose) {
+        LISTBASE_FOREACH (bPoseChannel *, pchan, &ob->pose->chanbase) {
+          do_version_constraints_spline_ik_joint_bindings(&pchan->constraints);
+        }
+      }
+    }
   }
 
   /**
diff --git a/source/blender/editors/object/object_constraint.c b/source/blender/editors/object/object_constraint.c
index 244124a6e0a..427596c2aee 100644
--- a/source/blender/editors/object/object_constraint.c
+++ b/source/blender/editors/object/object_constraint.c
@@ -432,11 +432,8 @@ static void test_constraint(
      * free the points array and request a rebind...
      */
     if ((data->points == NULL) || (data->numpoints != data->chainlen + 1)) {
-      /* free the points array */
-      if (data->points) {
-        MEM_freeN(data->points);
-        data->points = NULL;
-      }
+      MEM_SAFE_FREE(data->points);
+      data->numpoints = 0;
 
       /* clear the bound flag, forcing a rebind next time this is evaluated */
       data->flag &= ~CONSTRAINT_SPLINEIK_BOUND;