Re-fix T97366: Support single-file UDIMs

The original fix for T97366 was too restrictive and breaks real-world
cases of single-file UDIM textures. See D13297 for an example.

This patch effectively reverts the original fix and instead fixes the
downstream code to accept single-file ranges as necessary.

Note: This means it is very important for users to make use of the
"UDIM detection" option during `image.open` or drag n' drop scenarios in
order to declare their intent when loading their files.

Differential Revision: https://developer.blender.org/D14853

2 files changed, 5 insertions, 5 deletions

diff --git a/source/blender/editors/space_image/image_ops.c b/source/blender/editors/space_image/image_ops.c
index aa77aab2283..68d342e2143 100644
--- a/source/blender/editors/space_image/image_ops.c
+++ b/source/blender/editors/space_image/image_ops.c
@@ -1274,8 +1274,8 @@ static Image *image_open_single(Main *bmain,
       BKE_image_free_views(ima);
     }
 
-    if ((range->length > 1) && (ima->source == IMA_SRC_FILE)) {
-      if (range->udim_tiles.first) {
+    if (ima->source == IMA_SRC_FILE) {
+      if (range->udims_detected && range->udim_tiles.first) {
         ima->source = IMA_SRC_TILED;
         ImageTile *first_tile = ima->tiles.first;
         first_tile->tile_number = range->offset;
@@ -1283,7 +1283,7 @@ static Image *image_open_single(Main *bmain,
           BKE_image_add_tile(ima, POINTER_AS_INT(node->data), NULL);
         }
       }
-      else {
+      else if (range->length > 1) {
         ima->source = IMA_SRC_SEQUENCE;
       }
     }
diff --git a/source/blender/editors/space_image/image_sequence.c b/source/blender/editors/space_image/image_sequence.c
index 365cf2542b2..fbeef47e278 100644
--- a/source/blender/editors/space_image/image_sequence.c
+++ b/source/blender/editors/space_image/image_sequence.c
@@ -107,10 +107,10 @@ static void image_detect_frame_range(ImageFrameRange *range, const bool detect_u
   /* UDIM */
   if (detect_udim) {
     int udim_start, udim_range;
-    bool result = BKE_image_get_tile_info(
+    range->udims_detected = BKE_image_get_tile_info(
         range->filepath, &range->udim_tiles, &udim_start, &udim_range);
 
-    if (result) {
+    if (range->udims_detected) {
       range->offset = udim_start;
       range->length = udim_range;
       return;