Update runtime files.
diff --git a/runtime/doc/diff.txt b/runtime/doc/diff.txt
index 60ebb4f..452d0ac 100644
--- a/runtime/doc/diff.txt
+++ b/runtime/doc/diff.txt
@@ -1,4 +1,4 @@
-*diff.txt* For Vim version 8.1. Last change: 2019 May 04
+*diff.txt* For Vim version 8.1. Last change: 2019 Jun 02
VIM REFERENCE MANUAL by Bram Moolenaar
@@ -185,7 +185,7 @@
buffer. If you don't want a buffer to remain used for the diff do ":set
nodiff" before hiding it.
- *:dif* *:diffupdate*
+ *:dif* *:diff* *:diffupdate*
:dif[fupdate][!] Update the diff highlighting and folds.
Vim attempts to keep the differences updated when you make changes to the