(vc-mcvs-diff): Don't diff asynchronously if vc-disable-async-diff is

t.

1 files changed, 3 insertions, 1 deletions

diff --git a/lisp/vc-mcvs.el b/lisp/vc-mcvs.el
index ea577489239..aca8bcd66f0 100644
--- a/lisp/vc-mcvs.el
+++ b/lisp/vc-mcvs.el
@@ -446,7 +446,9 @@ The changes are between FIRST-VERSION and SECOND-VERSION."
                (append (vc-switches nil 'diff) '("/dev/null")))
         ;; Even if it's empty, it's locally modified.
         1)
-    (let* ((async (and (vc-stay-local-p file) (fboundp 'start-process)))
+    (let* ((async (and (not vc-disable-async-diff)
+                       (vc-stay-local-p file) 
+                       (fboundp 'start-process)))
            ;; Run the command from the root dir so that `mcvs filt' returns
            ;; valid relative names.
            (default-directory (vc-mcvs-root file))