Update runtime files.
diff --git a/runtime/syntax/diff.vim b/runtime/syntax/diff.vim
index b656cd9..ac43d66 100644
--- a/runtime/syntax/diff.vim
+++ b/runtime/syntax/diff.vim
@@ -2,7 +2,7 @@
" Language: Diff (context or unified)
" Maintainer: Bram Moolenaar <Bram@vim.org>
" Translations by Jakson Alves de Aquino.
-" Last Change: 2016 Apr 02
+" Last Change: 2020 Dec 07
" Quit when a (custom) syntax file was already loaded
if exists("b:current_syntax")
@@ -346,9 +346,11 @@
syn match diffLine "^\d\+\(,\d\+\)\=[cda]\d\+\>.*"
syn match diffFile "^diff\>.*"
-syn match diffFile "^+++ .*"
syn match diffFile "^Index: .*"
syn match diffFile "^==== .*"
+" Old style diff uses *** for old and --- for new.
+" Unified diff uses --- for old and +++ for new; names are wrong but it works.
+syn match diffOldFile "^+++ .*"
syn match diffOldFile "^\*\*\* .*"
syn match diffNewFile "^--- .*"