t5541-http-push.sh: add tests for non-fast-forward pushes

Signed-off-by: Tay Ray Chuan <rctay89@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
diff --git a/t/t5541-http-push.sh b/t/t5541-http-push.sh
index 2a58d0c..f49c7c4 100755
--- a/t/t5541-http-push.sh
+++ b/t/t5541-http-push.sh
@@ -88,5 +88,28 @@
 	test_cmp exp act
 '
 
+test_expect_success 'non-fast-forward push fails' '
+	cd "$ROOT_PATH"/test_repo_clone &&
+	git checkout master &&
+	echo "changed" > path2 &&
+	git commit -a -m path2 --amend &&
+
+	HEAD=$(git rev-parse --verify HEAD) &&
+	!(git push -v origin >output 2>&1) &&
+	(cd "$HTTPD_DOCUMENT_ROOT_PATH"/test_repo.git &&
+	 test $HEAD != $(git rev-parse --verify HEAD))
+'
+
+test_expect_failure 'non-fast-forward push show ref status' '
+	grep "^ ! \[rejected\][ ]*master -> master (non-fast-forward)$" output
+'
+
+test_expect_failure 'non-fast-forward push shows help message' '
+	grep \
+"To prevent you from losing history, non-fast-forward updates were rejected
+Merge the remote changes before pushing again.  See the '"'non-fast-forward'"'
+section of '"'git push --help'"' for details." output
+'
+
 stop_httpd
 test_done