[PATCH] difftool: honor --trust-exit-code for builtin tools

[David Aguilar <davvid@gmail.com>]

run_merge_tool() was not setting $status, which prevented the
exit code for builtin tools from being forwarded to the caller.

Capture the exit status and add a test to guarantee the behavior.

Reported-by: Adria Farres <14farresa@gmail.com>
Signed-off-by: David Aguilar <davvid@gmail.com>
---
 git-mergetool--lib.sh | 1 +
 t/t7800-difftool.sh   | 5 +++++
 2 files changed, 6 insertions(+)

diff --git a/git-mergetool--lib.sh b/git-mergetool--lib.sh
index a40d3df..2b66351 100644
--- a/git-mergetool--lib.sh
+++ b/git-mergetool--lib.sh
@@ -221,6 +221,7 @@ run_merge_tool () {
 	else
 		run_diff_cmd "$1"
 	fi
+	status=$?
 	return $status
 }
 
diff --git a/t/t7800-difftool.sh b/t/t7800-difftool.sh
index 69bde7a..ea35a02 100755
--- a/t/t7800-difftool.sh
+++ b/t/t7800-difftool.sh
@@ -86,6 +86,11 @@ test_expect_success PERL 'difftool forwards exit code with --trust-exit-code' '
 	test_must_fail git difftool -y --trust-exit-code -t error branch
 '
 
+test_expect_success PERL 'difftool forwards exit code with --trust-exit-code for built-ins' '
+	test_config difftool.vimdiff.path false &&
+	test_must_fail git difftool -y --trust-exit-code -t vimdiff branch
+'
+
 test_expect_success PERL 'difftool honors difftool.trustExitCode = true' '
 	test_config difftool.error.cmd false &&
 	test_config difftool.trustExitCode true &&
-- 
2.2.0.rc1.23.gf570943.dirty