Fix T78608: Memory leak in Material properties: "Data from SCE".

Caused by recent own refactor of cache presevation handling in readfile,
EEVEE's lightcache are weird birds that can also be saved in .blend
files, need a special handling for those 'persistent' caches...

source/blender/blenkernel/BKE_idtype.h

@@ -76,9 +76,15 @@ typedef void (*IDTypeMakeLocalFunction)(struct Main *bmain, struct ID *id, const
 
 typedef void (*IDTypeForeachIDFunction)(struct ID *id, struct LibraryForeachIDData *data);
 
+typedef enum eIDTypeInfoCacheCallbackFlags {
+  /** Indicates to the callback that that cache may be stored in the .blend file, so its pointer
+   * should not be cleared at readtime.*/
+  IDTYPE_CACHE_CB_FLAGS_PERSISTENT = 1 << 0,
+} eIDTypeInfoCacheCallbackFlags;
 typedef void (*IDTypeForeachCacheFunctionCallback)(struct ID *id,
                                                    const struct IDCacheKey *cache_key,
                                                    void **cache_p,
+                                                   uint flags,
                                                    void *user_data);
 typedef void (*IDTypeForeachCacheFunction)(struct ID *id,
                                            IDTypeForeachCacheFunctionCallback function_callback,

source/blender/blenkernel/intern/image.c

@@ -195,24 +195,24 @@ static void image_foreach_cache(ID *id,
       .offset_in_ID = offsetof(Image, cache),
       .cache_v = image->cache,
   };
-  function_callback(id, &key, (void **)&image->cache, user_data);
+  function_callback(id, &key, (void **)&image->cache, 0, user_data);
 
   for (int eye = 0; eye < 2; eye++) {
     for (int a = 0; a < TEXTARGET_COUNT; a++) {
       key.offset_in_ID = offsetof(Image, gputexture[a][eye]);
       key.cache_v = image->gputexture[a][eye];
-      function_callback(id, &key, (void **)&image->gputexture[a][eye], user_data);
+      function_callback(id, &key, (void **)&image->gputexture[a][eye], 0, user_data);
     }
   }
 
   key.offset_in_ID = offsetof(Image, rr);
   key.cache_v = image->rr;
-  function_callback(id, &key, (void **)&image->rr, user_data);
+  function_callback(id, &key, (void **)&image->rr, 0, user_data);
 
   LISTBASE_FOREACH (RenderSlot *, slot, &image->renderslots) {
     key.offset_in_ID = (size_t)BLI_ghashutil_strhash_p(slot->name);
     key.cache_v = slot->render;
-    function_callback(id, &key, (void **)&slot->render, user_data);
+    function_callback(id, &key, (void **)&slot->render, 0, user_data);
   }
 }
 

source/blender/blenkernel/intern/movieclip.c

@@ -139,11 +139,11 @@ static void movie_clip_foreach_cache(ID *id,
       .offset_in_ID = offsetof(MovieClip, cache),
       .cache_v = movie_clip->cache,
   };
-  function_callback(id, &key, (void **)&movie_clip->cache, user_data);
+  function_callback(id, &key, (void **)&movie_clip->cache, 0, user_data);
 
   key.offset_in_ID = offsetof(MovieClip, tracking.camera.intrinsics);
   key.cache_v = movie_clip->tracking.camera.intrinsics;
-  function_callback(id, &key, (void **)&movie_clip->tracking.camera.intrinsics, user_data);
+  function_callback(id, &key, (void **)&movie_clip->tracking.camera.intrinsics, 0, user_data);
 }
 
 IDTypeInfo IDType_ID_MC = {

source/blender/blenkernel/intern/scene.c

@@ -581,7 +581,11 @@ static void scene_foreach_cache(ID *id,
       .cache_v = scene->eevee.light_cache_data,
   };
 
-  function_callback(id, &key, (void **)&scene->eevee.light_cache_data, user_data);
+  function_callback(id,
+                    &key,
+                    (void **)&scene->eevee.light_cache_data,
+                    IDTYPE_CACHE_CB_FLAGS_PERSISTENT,
+                    user_data);
 }
 
 IDTypeInfo IDType_ID_SCE = {

source/blender/blenkernel/intern/sound.c

@@ -123,7 +123,7 @@ static void sound_foreach_cache(ID *id,
       .cache_v = sound->waveform,
   };
 
-  function_callback(id, &key, &sound->waveform, user_data);
+  function_callback(id, &key, &sound->waveform, 0, user_data);
 }
 
 IDTypeInfo IDType_ID_SO = {

source/blender/blenkernel/intern/volume.cc

@@ -494,7 +494,7 @@ static void volume_foreach_cache(ID *id,
       /* cache_v */ volume->runtime.grids,
   };
 
-  function_callback(id, &key, (void **)&volume->runtime.grids, user_data);
+  function_callback(id, &key, (void **)&volume->runtime.grids, 0, user_data);
 }
 
 IDTypeInfo IDType_ID_VO = {

source/blender/blenloader/intern/readfile.c

@@ -2263,6 +2263,7 @@ typedef struct BLOCacheStorage {
 static void blo_cache_storage_entry_register(ID *id,
                                              const IDCacheKey *key,
                                              void **UNUSED(cache_p),
+                                             eIDTypeInfoCacheCallbackFlags UNUSED(flags),
                                              void *cache_storage_v)
 {
   BLI_assert(key->id_session_uuid == id->session_uuid);
@@ -2280,12 +2281,18 @@ static void blo_cache_storage_entry_register(ID *id,
 static void blo_cache_storage_entry_restore_in_new(ID *UNUSED(id),
                                                    const IDCacheKey *key,
                                                    void **cache_p,
+                                                   eIDTypeInfoCacheCallbackFlags flags,
                                                    void *cache_storage_v)
 {
   BLOCacheStorage *cache_storage = cache_storage_v;
 
   if (cache_storage == NULL) {
-    *cache_p = NULL;
+    /* In non-undo case, only clear the pointer if it is a purely runtime one.
+     * If it may be stored in a persistent way in the .blend file, direct_link code is responsible
+     * to properly deal with it. */
+    if ((flags & IDTYPE_CACHE_CB_FLAGS_PERSISTENT) == 0) {
+      *cache_p = NULL;
+    }
     return;
   }
 
@@ -2302,6 +2309,7 @@ static void blo_cache_storage_entry_restore_in_new(ID *UNUSED(id),
 static void blo_cache_storage_entry_clear_in_old(ID *UNUSED(id),
                                                  const IDCacheKey *key,
                                                  void **cache_p,
+                                                 eIDTypeInfoCacheCallbackFlags UNUSED(flags),
                                                  void *cache_storage_v)
 {
   BLOCacheStorage *cache_storage = cache_storage_v;
@@ -9249,8 +9257,8 @@ static BHead *read_data_into_datamap(FileData *fd, BHead *bhead, const char *all
     void *data;
 #if 0
     /* XXX DUMB DEBUGGING OPTION TO GIVE NAMES for guarded malloc errors */
-    short* sp = fd->filesdna->structs[bhead->SDNAnr];
-    char* tmp = malloc(100);
+    short *sp = fd->filesdna->structs[bhead->SDNAnr];
+    char *tmp = malloc(100);
     allocname = fd->filesdna->types[sp[0]];
     strcpy(tmp, allocname);
     data = read_struct(fd, bhead, tmp);