4 files changed, 33 insertions, 7 deletions
diff --git a/source/blender/blenloader/BLO_readfile.h b/source/blender/blenloader/BLO_readfile.h
index c85cf128643..e07d567ce61 100644
--- a/source/blender/blenloader/BLO_readfile.h
+++ b/source/blender/blenloader/BLO_readfile.h
@@ -71,11 +71,21 @@ typedef struct BlendFileData {
 	BlenFileType type;
 } BlendFileData;
 
-BlendFileData *BLO_read_from_file(const char *filepath, struct ReportList *reports);
-BlendFileData *BLO_read_from_memory(const void *mem, int memsize, struct ReportList *reports);
+
+/* skip reading some data-block types (may want to skip screen data too). */
+typedef enum eBLOReadSkip {
+	BLO_READ_SKIP_USERDEF = (1 << 0),
+} eBLOReadSkip;
+
+BlendFileData *BLO_read_from_file(
+        const char *filepath,
+        struct ReportList *reports, eBLOReadSkip skip_flag);
+BlendFileData *BLO_read_from_memory(
+        const void *mem, int memsize,
+        struct ReportList *reports, eBLOReadSkip skip_flag);
 BlendFileData *BLO_read_from_memfile(
         struct Main *oldmain, const char *filename, struct MemFile *memfile,
-        struct ReportList *reports);
+        struct ReportList *reports, eBLOReadSkip skip_flag);
 
 void BLO_blendfiledata_free(BlendFileData *bfd);
 
diff --git a/source/blender/blenloader/intern/readblenentry.c b/source/blender/blenloader/intern/readblenentry.c
index be893177b3b..73109413271 100644
--- a/source/blender/blenloader/intern/readblenentry.c
+++ b/source/blender/blenloader/intern/readblenentry.c
@@ -317,7 +317,9 @@ void BLO_blendhandle_close(BlendHandle *bh)
  * \param reports If the return value is NULL, errors indicating the cause of the failure.
  * \return The data of the file.
  */
-BlendFileData *BLO_read_from_file(const char *filepath, ReportList *reports)
+BlendFileData *BLO_read_from_file(
+        const char *filepath,
+        ReportList *reports, eBLOReadSkip skip_flags)
 {
 	BlendFileData *bfd = NULL;
 	FileData *fd;
@@ -325,6 +327,7 @@ BlendFileData *BLO_read_from_file(const char *filepath, ReportList *reports)
 	fd = blo_openblenderfile(filepath, reports);
 	if (fd) {
 		fd->reports = reports;
+		fd->skip_flags = skip_flags;
 		bfd = blo_read_file_internal(fd, filepath);
 		blo_freefiledata(fd);
 	}
@@ -341,7 +344,9 @@ BlendFileData *BLO_read_from_file(const char *filepath, ReportList *reports)
  * \param reports If the return value is NULL, errors indicating the cause of the failure.
  * \return The data of the file.
  */
-BlendFileData *BLO_read_from_memory(const void *mem, int memsize, ReportList *reports)
+BlendFileData *BLO_read_from_memory(
+        const void *mem, int memsize,
+        ReportList *reports, eBLOReadSkip skip_flags)
 {
 	BlendFileData *bfd = NULL;
 	FileData *fd;
@@ -349,6 +354,7 @@ BlendFileData *BLO_read_from_memory(const void *mem, int memsize, ReportList *re
 	fd = blo_openblendermemory(mem, memsize,  reports);
 	if (fd) {
 		fd->reports = reports;
+		fd->skip_flags = skip_flags;
 		bfd = blo_read_file_internal(fd, "");
 		blo_freefiledata(fd);
 	}
@@ -362,7 +368,9 @@ BlendFileData *BLO_read_from_memory(const void *mem, int memsize, ReportList *re
  * \param oldmain old main, from which we will keep libraries and other datablocks that should not have changed.
  * \param filename current file, only for retrieving library data.
  */
-BlendFileData *BLO_read_from_memfile(Main *oldmain, const char *filename, MemFile *memfile, ReportList *reports)
+BlendFileData *BLO_read_from_memfile(
+        Main *oldmain, const char *filename, MemFile *memfile,
+        ReportList *reports, eBLOReadSkip skip_flags)
 {
 	BlendFileData *bfd = NULL;
 	FileData *fd;
@@ -371,6 +379,7 @@ BlendFileData *BLO_read_from_memfile(Main *oldmain, const char *filename, MemFil
 	fd = blo_openblendermemfile(memfile, reports);
 	if (fd) {
 		fd->reports = reports;
+		fd->skip_flags = skip_flags;
 		BLI_strncpy(fd->relabase, filename, sizeof(fd->relabase));
 		
 		/* clear ob->proxy_from pointers in old main */
diff --git a/source/blender/blenloader/intern/readfile.c b/source/blender/blenloader/intern/readfile.c
index 638f877c841..91c96aef8e8 100644
--- a/source/blender/blenloader/intern/readfile.c
+++ b/source/blender/blenloader/intern/readfile.c
@@ -8597,7 +8597,12 @@ BlendFileData *blo_read_file_internal(FileData *fd, const char *filepath)
 			bhead = read_global(bfd, fd, bhead);
 			break;
 		case USER:
-			bhead = read_userdef(bfd, fd, bhead);
+			if (fd->skip_flags & BLO_READ_SKIP_USERDEF) {
+				bhead = blo_nextbhead(fd, bhead);
+			}
+			else {
+				bhead = read_userdef(bfd, fd, bhead);
+			}
 			break;
 		case ENDB:
 			bhead = NULL;
diff --git a/source/blender/blenloader/intern/readfile.h b/source/blender/blenloader/intern/readfile.h
index d97bef13a78..62ce15a640e 100644
--- a/source/blender/blenloader/intern/readfile.h
+++ b/source/blender/blenloader/intern/readfile.h
@@ -81,6 +81,8 @@ typedef struct FileData {
 	int id_name_offs;       /* used to retrieve ID names from (bhead+1) */
 	int globalf, fileflags; /* for do_versions patching */
 	
+	eBLOReadSkip skip_flags;  /* skip some data-blocks */
+
 	struct OldNewMap *datamap;
 	struct OldNewMap *globmap;
 	struct OldNewMap *libmap;