Merge branch 'sd/stash-wo-user-name'

A properly configured username/email is required under
user.useConfigOnly in order to create commits; now "git stash"
(even though it creates commit objects to represent stash entries)
command is exempt from the requirement.

* sd/stash-wo-user-name:
  stash: tolerate missing user identity

git-stash.sh

@@ -55,6 +55,20 @@ untracked_files () {
 	git ls-files -o $z $excl_opt -- "$@"
 }
 
+prepare_fallback_ident () {
+	if ! git -c user.useconfigonly=yes var GIT_COMMITTER_IDENT >/dev/null 2>&1
+	then
+		GIT_AUTHOR_NAME="git stash"
+		GIT_AUTHOR_EMAIL=git@stash
+		GIT_COMMITTER_NAME="git stash"
+		GIT_COMMITTER_EMAIL=git@stash
+		export GIT_AUTHOR_NAME
+		export GIT_AUTHOR_EMAIL
+		export GIT_COMMITTER_NAME
+		export GIT_COMMITTER_EMAIL
+	fi
+}
+
 clear_stash () {
 	if test $# != 0
 	then
@@ -67,6 +81,9 @@ clear_stash () {
 }
 
 create_stash () {
+
+	prepare_fallback_ident
+
 	stash_msg=
 	untracked=
 	while test $# != 0

t/t3903-stash.sh

@@ -1096,4 +1096,32 @@ test_expect_success 'stash -- <subdir> works with binary files' '
 	test_path_is_file subdir/untracked
 '
 
+test_expect_success 'stash works when user.name and user.email are not set' '
+	git reset &&
+	>1 &&
+	git add 1 &&
+	echo "$GIT_AUTHOR_NAME <$GIT_AUTHOR_EMAIL>" >expect &&
+	git stash &&
+	git show -s --format="%an <%ae>" refs/stash >actual &&
+	test_cmp expect actual &&
+	>2 &&
+	git add 2 &&
+	test_config user.useconfigonly true &&
+	test_config stash.usebuiltin true &&
+	(
+		sane_unset GIT_AUTHOR_NAME &&
+		sane_unset GIT_AUTHOR_EMAIL &&
+		sane_unset GIT_COMMITTER_NAME &&
+		sane_unset GIT_COMMITTER_EMAIL &&
+		test_unconfig user.email &&
+		test_unconfig user.name &&
+		test_must_fail git commit -m "should fail" &&
+		echo "git stash <git@stash>" >expect &&
+		>2 &&
+		git stash &&
+		git show -s --format="%an <%ae>" refs/stash >actual &&
+		test_cmp expect actual
+	)
+'
+
 test_done