Fix for recent library linking fix, this triggered another issue that was

hidden by libraries getting loaded twice, hopefully it's working ok now,
tested with various .blend files.

1 files changed, 12 insertions, 5 deletions

diff --git a/source/blender/blenloader/intern/readfile.c b/source/blender/blenloader/intern/readfile.c
index 8710c5fe075..8e9394a886e 100644
--- a/source/blender/blenloader/intern/readfile.c
+++ b/source/blender/blenloader/intern/readfile.c
@@ -7859,10 +7859,17 @@ static void expand_doit(FileData *fd, Main *mainvar, void *old)
 					
 					/* Update: the issue is that in file reading, the oldnewmap is OK, but for existing data, it has to be
 					 * inserted in the map to be found! */
-					if (id->flag & LIB_PRE_EXISTING)
-						oldnewmap_insert(fd->libmap, bhead->old, id, 1);
-					
+
+					/* Update: previously it was checking for id->flag & LIB_PRE_EXISTING, however that does not affect file
+					 * reading. For file reading we may need to insert it into the libmap as well, because you might have
+					 * two files indirectly linking the same datablock, and in that case we need this in the libmap for the
+					 * fd of both those files.
+					 *
+					 * The crash that this check avoided earlier was because bhead->code wasn't properly passed in, making
+					 * change_idid_adr not detect the mapping was for an ID_ID datablock. */
+					oldnewmap_insert(fd->libmap, bhead->old, id, bhead->code);
 					change_idid_adr_fd(fd, bhead->old, id);
+					
 					// commented because this can print way too much
 					// if (G.debug & G_DEBUG) printf("expand_doit: already linked: %s lib: %s\n", id->name, lib->name);
 				}
@@ -7878,7 +7885,7 @@ static void expand_doit(FileData *fd, Main *mainvar, void *old)
 			else {
 				/* this is actually only needed on UI call? when ID was already read before, and another append
 				 * happens which invokes same ID... in that case the lookup table needs this entry */
-				oldnewmap_insert(fd->libmap, bhead->old, id, 1);
+				oldnewmap_insert(fd->libmap, bhead->old, id, bhead->code);
 				// commented because this can print way too much
 				// if (G.debug & G_DEBUG) printf("expand: already read %s\n", id->name);
 			}
@@ -8763,7 +8770,7 @@ static ID *append_named_part(Main *mainl, FileData *fd, const char *idname, cons
 				else {
 					/* already linked */
 					printf("append: already linked\n");
-					oldnewmap_insert(fd->libmap, bhead->old, id, 1);
+					oldnewmap_insert(fd->libmap, bhead->old, id, bhead->code);
 					if (id->flag & LIB_INDIRECT) {
 						id->flag -= LIB_INDIRECT;
 						id->flag |= LIB_EXTERN;