patch 8.1.0394: diffs are not always updated correctly
Problem: Diffs are not always updated correctly.
Solution: When using internal diff update for any changes properly.
diff --git a/src/proto/diff.pro b/src/proto/diff.pro
index f1afeec..d6ab221 100644
--- a/src/proto/diff.pro
+++ b/src/proto/diff.pro
@@ -4,6 +4,7 @@
void diff_buf_add(buf_T *buf);
void diff_invalidate(buf_T *buf);
void diff_mark_adjust(linenr_T line1, linenr_T line2, long amount, long amount_after);
+int diff_internal(void);
void ex_diffupdate(exarg_T *eap);
void ex_diffpatch(exarg_T *eap);
void ex_diffsplit(exarg_T *eap);