[Bf-blender-cvs] [3346ab0] master: Fix/workaround T37073: Crash updating custom props visible in the UI

[Campbell Barton]

Commit: 3346ab034804c0d93e1c20d62e82dff4839b861a
Author: Campbell Barton
Date:   Mon Nov 10 17:10:58 2014 +0100
Branches: master
https://developer.blender.org/rB3346ab034804c0d93e1c20d62e82dff4839b861a

Fix/workaround T37073: Crash updating custom props visible in the UI

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

M	source/blender/blenkernel/BKE_idprop.h
M	source/blender/blenkernel/intern/idprop.c
M	source/blender/python/generic/idprop_py_api.c

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

diff --git a/source/blender/blenkernel/BKE_idprop.h b/source/blender/blenkernel/BKE_idprop.h
index cb73cc2..6d3d15e 100644
--- a/source/blender/blenkernel/BKE_idprop.h
+++ b/source/blender/blenkernel/BKE_idprop.h
@@ -91,6 +91,7 @@ void IDP_SyncGroupValues(struct IDProperty *dest, const struct IDProperty *src)
 void IDP_SyncGroupTypes(struct IDProperty *dest, const struct IDProperty *src, const bool do_arraylen) ATTR_NONNULL();
 void IDP_ReplaceGroupInGroup(struct IDProperty *dest, const struct IDProperty *src) ATTR_NONNULL();
 void IDP_ReplaceInGroup(struct IDProperty *group, struct IDProperty *prop) ATTR_NONNULL();
+void IDP_ReplaceInGroup_ex(struct IDProperty *group, struct IDProperty *prop, struct IDProperty *prop_exist);
 void IDP_MergeGroup(IDProperty *dest, const IDProperty *src, const bool do_overwrite) ATTR_NONNULL();
 bool IDP_AddToGroup(struct IDProperty *group, struct IDProperty *prop) ATTR_NONNULL();
 bool IDP_InsertToGroup(struct IDProperty *group, struct IDProperty *previous,
diff --git a/source/blender/blenkernel/intern/idprop.c b/source/blender/blenkernel/intern/idprop.c
index 5c06d5b..23e7778 100644
--- a/source/blender/blenkernel/intern/idprop.c
+++ b/source/blender/blenkernel/intern/idprop.c
@@ -571,18 +571,18 @@ void IDP_ReplaceGroupInGroup(IDProperty *dest, const IDProperty *src)
  * Checks if a property with the same name as prop exists, and if so replaces it.
  * Use this to preserve order!
  */
-void IDP_ReplaceInGroup(IDProperty *group, IDProperty *prop)
+void IDP_ReplaceInGroup_ex(IDProperty *group, IDProperty *prop, IDProperty *prop_exist)
 {
-	IDProperty *loop;
-
 	BLI_assert(group->type == IDP_GROUP);
 
-	if ((loop = IDP_GetPropertyFromGroup(group, prop->name))) {
-		BLI_insertlinkafter(&group->data.group, loop, prop);
+	BLI_assert(prop_exist == IDP_GetPropertyFromGroup(group, prop->name));
+
+	if ((prop_exist = IDP_GetPropertyFromGroup(group, prop->name))) {
+		BLI_insertlinkafter(&group->data.group, prop_exist, prop);
 		
-		BLI_remlink(&group->data.group, loop);
-		IDP_FreeProperty(loop);
-		MEM_freeN(loop);
+		BLI_remlink(&group->data.group, prop_exist);
+		IDP_FreeProperty(prop_exist);
+		MEM_freeN(prop_exist);
 	}
 	else {
 		group->len++;
@@ -590,6 +590,13 @@ void IDP_ReplaceInGroup(IDProperty *group, IDProperty *prop)
 	}
 }
 
+void IDP_ReplaceInGroup(IDProperty *group, IDProperty *prop)
+{
+	IDProperty *prop_exist = IDP_GetPropertyFromGroup(group, prop->name);
+
+	IDP_ReplaceInGroup_ex(group, prop, prop_exist);
+}
+
 /**
  * If a property is missing in \a dest, add it.
  */
diff --git a/source/blender/python/generic/idprop_py_api.c b/source/blender/python/generic/idprop_py_api.c
index 8c9e84a..d2920df 100644
--- a/source/blender/python/generic/idprop_py_api.c
+++ b/source/blender/python/generic/idprop_py_api.c
@@ -510,7 +510,22 @@ bool BPy_IDProperty_Map_ValidateAndCreate(PyObject *name_obj, IDProperty *group,
 		MEM_freeN(prop);
 	}
 	else {
-		IDP_ReplaceInGroup(group, prop);
+		IDProperty *prop_exist;
+
+		/* avoid freeing when types match incase they are referenced by the UI, see: T37073
+		 * obviously this isn't a complete solution, but helps for common cases. */
+		prop_exist = IDP_GetPropertyFromGroup(group, prop->name);
+		if ((prop_exist != NULL) &&
+		    (prop_exist->type == prop->type) &&
+		    (prop_exist->subtype == prop->subtype))
+		{
+			IDP_FreeProperty(prop_exist);
+			*prop_exist = *prop;
+			MEM_freeN(prop);
+		}
+		else {
+			IDP_ReplaceInGroup_ex(group, prop, prop_exist);
+		}
 	}
 
 	return true;