Add the 'undoreload' option to be able to undo a file reload.
diff --git a/src/vim.h b/src/vim.h
index ce55514..6790a48 100644
--- a/src/vim.h
+++ b/src/vim.h
@@ -953,6 +953,7 @@
#define READ_STDIN 0x04 /* read from stdin */
#define READ_BUFFER 0x08 /* read from curbuf (converting stdin) */
#define READ_DUMMY 0x10 /* reading into a dummy buffer */
+#define READ_KEEP_UNDO 0x20 /* keep undo info*/
/* Values for change_indent() */
#define INDENT_SET 1 /* set indent */
@@ -2174,4 +2175,9 @@
#define VIF_FORCEIT 4 /* overwrite info already read */
#define VIF_GET_OLDFILES 8 /* load v:oldfiles */
+/* flags for buf_freeall() */
+#define BFA_DEL 1 /* buffer is going to be deleted */
+#define BFA_WIPE 2 /* buffer is going to be wiped out */
+#define BFA_KEEP_UNDO 4 /* do not free undo information */
+
#endif /* VIM__H */