Documentation/git-bisect.txt: add --no-ff to merge command

Mihail Atanassov · gitster · commit 8dd327b2465c · 2019-10-29T11:53:56.000+09:00
The hotfix application example uses `git merge --no-commit` to apply
temporary changes to the working tree during a bisect operation. In some
situations this can be a fast-forward and `merge` will apply the hotfix
branch's commits regardless of `--no-commit` (as documented in the `git
merge` manual).

In the pathological case this will make a `git bisect run` invocation
loop indefinitely between the first bisect step and the fast-forwarded
post-merge HEAD.

Add `--no-ff` to the merge command to avoid this issue.

Signed-off-by: Mihail Atanassov &lt;m.atanassov92@gmail.com&gt;
Reviewed-by: Jonathan Nieder &lt;jrnieder@gmail.com&gt;
Signed-off-by: Junio C Hamano &lt;gitster@pobox.com&gt;
diff --git a/Documentation/git-bisect.txt b/Documentation/git-bisect.txt
@@ -413,7 +413,7 @@ $ cat ~/test.sh
 
 # tweak the working tree by merging the hot-fix branch
 # and then attempt a build
-if	git merge --no-commit hot-fix &&
+if	git merge --no-commit --no-ff hot-fix &&
 	make
 then
 	# run project specific test and report its status
