Undo: refactor memfile writing

- Move static undo variable into 'WriteData',
  'memfile_chunk_add' used arguments in a confusing way,
  sometimes to set/clear static var.

- Replace checks for 'wd->current' with 'wd->use_memfile'
  move memfile vars into 'wd->mem' struct.

1 files changed, 3 insertions, 1 deletions

diff --git a/source/blender/blenloader/BLO_undofile.h b/source/blender/blenloader/BLO_undofile.h
index b713b963056..c407ea31b9b 100644
--- a/source/blender/blenloader/BLO_undofile.h
+++ b/source/blender/blenloader/BLO_undofile.h
@@ -56,7 +56,9 @@ typedef struct MemFileUndoData {
 } MemFileUndoData;
 
 /* actually only used writefile.c */
-extern void memfile_chunk_add(MemFile *compare, MemFile *current, const char *buf, unsigned int size);
+extern void memfile_chunk_add(
+        MemFile *memfile, const char *buf, unsigned int size,
+        MemFileChunk **compchunk_step);
 
 /* exports */
 extern void BLO_memfile_free(MemFile *memfile);