Fix T69663: 2.81 Cant open/append/link a blend file but 2.8 can

Was a problem in the versioning code from rBbaaa89a0bc54, since the
TexMapping struct could already be freed and node->storage could already
be set to NULL (if a file with the new mapping node [saved from (2, 81,
8) or newer] is opened in a blender version prior to (2, 81, 8) and
saved from there again).

Reviewers: brecht

Maniphest Tasks: T69663

Differential Revision: https://developer.blender.org/D5723

1 files changed, 4 insertions, 1 deletions

diff --git a/source/blender/blenloader/intern/versioning_cycles.c b/source/blender/blenloader/intern/versioning_cycles.c
index 1abf099b4c2..d4d940daba5 100644
--- a/source/blender/blenloader/intern/versioning_cycles.c
+++ b/source/blender/blenloader/intern/versioning_cycles.c
@@ -797,7 +797,10 @@ static void update_mapping_node_inputs_and_properties(bNodeTree *ntree)
   bool need_update = false;
 
   for (bNode *node = ntree->nodes.first; node; node = node->next) {
-    if (node->type == SH_NODE_MAPPING) {
+    /* If node->storage is NULL, then conversion has already taken place.
+     * This can happen if a file with the new mapping node [saved from (2, 81, 8) or newer]
+     * is opened in a blender version prior to (2, 81, 8) and saved from there again. */
+    if (node->type == SH_NODE_MAPPING && node->storage) {
       TexMapping *mapping = (TexMapping *)node->storage;
       node->custom1 = mapping->type;
       node->width = 140.0f;