1 files changed, 190 insertions, 0 deletions
diff --git a/t/t4017-diff-retval.sh b/t/t4017-diff-retval.sh
new file mode 100755
index 0000000000..c2863c99b7
--- /dev/null
+++ b/t/t4017-diff-retval.sh
@@ -0,0 +1,190 @@
+#!/bin/sh
+
+test_description='Return value of diffs'
+
+GIT_TEST_DEFAULT_INITIAL_BRANCH_NAME=main
+export GIT_TEST_DEFAULT_INITIAL_BRANCH_NAME
+
+. ./test-lib.sh
+
+test_expect_success 'setup' '
+	echo "1 " >a &&
+	git add . &&
+	git commit -m zeroth &&
+	echo 1 >a &&
+	git add . &&
+	git commit -m first &&
+	echo 2 >b &&
+	git add . &&
+	git commit -a -m second
+'
+
+test_expect_success 'git diff --quiet -w  HEAD^^ HEAD^' '
+	git diff --quiet -w HEAD^^ HEAD^
+'
+
+test_expect_success 'git diff --quiet HEAD^^ HEAD^' '
+	test_must_fail git diff --quiet HEAD^^ HEAD^
+'
+
+test_expect_success 'git diff --quiet -w  HEAD^ HEAD' '
+	test_must_fail git diff --quiet -w HEAD^ HEAD
+'
+
+test_expect_success 'git diff-tree HEAD^ HEAD' '
+	test_expect_code 1 git diff-tree --exit-code HEAD^ HEAD
+'
+test_expect_success 'git diff-tree HEAD^ HEAD -- a' '
+	git diff-tree --exit-code HEAD^ HEAD -- a
+'
+test_expect_success 'git diff-tree HEAD^ HEAD -- b' '
+	test_expect_code 1 git diff-tree --exit-code HEAD^ HEAD -- b
+'
+test_expect_success 'echo HEAD | git diff-tree --stdin' '
+	echo $(git rev-parse HEAD) | test_expect_code 1 git diff-tree --exit-code --stdin
+'
+test_expect_success 'git diff-tree HEAD HEAD' '
+	git diff-tree --exit-code HEAD HEAD
+'
+test_expect_success 'git diff-files' '
+	git diff-files --exit-code
+'
+test_expect_success 'git diff-index --cached HEAD' '
+	git diff-index --exit-code --cached HEAD
+'
+test_expect_success 'git diff-index --cached HEAD^' '
+	test_expect_code 1 git diff-index --exit-code --cached HEAD^
+'
+test_expect_success 'git diff-index --cached HEAD^' '
+	echo text >>b &&
+	echo 3 >c &&
+	git add . &&
+	test_expect_code 1 git diff-index --exit-code --cached HEAD^
+'
+test_expect_success 'git diff-tree -Stext HEAD^ HEAD -- b' '
+	git commit -m "text in b" &&
+	test_expect_code 1 git diff-tree -p --exit-code -Stext HEAD^ HEAD -- b
+'
+test_expect_success 'git diff-tree -Snot-found HEAD^ HEAD -- b' '
+	git diff-tree -p --exit-code -Snot-found HEAD^ HEAD -- b
+'
+test_expect_success 'git diff-files' '
+	echo 3 >>c &&
+	test_expect_code 1 git diff-files --exit-code
+'
+test_expect_success 'git diff-index --cached HEAD' '
+	git update-index c &&
+	test_expect_code 1 git diff-index --exit-code --cached HEAD
+'
+
+test_expect_success '--check --exit-code returns 0 for no difference' '
+
+	git diff --check --exit-code
+
+'
+
+test_expect_success '--check --exit-code returns 1 for a clean difference' '
+
+	echo "good" > a &&
+	test_expect_code 1 git diff --check --exit-code
+
+'
+
+test_expect_success '--check --exit-code returns 3 for a dirty difference' '
+
+	echo "bad   " >> a &&
+	test_expect_code 3 git diff --check --exit-code
+
+'
+
+test_expect_success '--check with --no-pager returns 2 for dirty difference' '
+
+	test_expect_code 2 git --no-pager diff --check
+
+'
+
+test_expect_success 'check should test not just the last line' '
+	echo "" >>a &&
+	test_expect_code 2 git --no-pager diff --check
+
+'
+
+test_expect_success 'check detects leftover conflict markers' '
+	git reset --hard &&
+	git checkout HEAD^ &&
+	echo binary >>b &&
+	git commit -m "side" b &&
+	test_must_fail git merge main &&
+	git add b &&
+	test_expect_code 2 git --no-pager diff --cached --check >test.out &&
+	test 3 = $(grep "conflict marker" test.out | wc -l) &&
+	git reset --hard
+'
+
+test_expect_success 'check honors conflict marker length' '
+	git reset --hard &&
+	echo ">>>>>>> boo" >>b &&
+	echo "======" >>a &&
+	git diff --check a &&
+	test_expect_code 2 git diff --check b &&
+	git reset --hard &&
+	echo ">>>>>>>> boo" >>b &&
+	echo "========" >>a &&
+	git diff --check &&
+	echo "b conflict-marker-size=8" >.gitattributes &&
+	test_expect_code 2 git diff --check b &&
+	git diff --check a &&
+	git reset --hard
+'
+
+test_expect_success 'option errors are not confused by --exit-code' '
+	test_must_fail git diff --exit-code --nonsense 2>err &&
+	grep '^usage:' err
+'
+
+for option in --exit-code --quiet
+do
+	test_expect_success "git diff $option returns 1 for changed binary file" "
+		test_when_finished 'rm -f .gitattributes' &&
+		git reset --hard &&
+		echo a binary >.gitattributes &&
+		echo 2 >>a &&
+		test_expect_code 1 git diff $option
+	"
+
+	test_expect_success "git diff $option returns 1 for copied file" "
+		git reset --hard &&
+		cp a copy &&
+		git add copy &&
+		test_expect_code 1 git diff $option --cached --find-copies-harder
+	"
+
+	test_expect_success "git diff $option returns 1 for renamed file" "
+		git reset --hard &&
+		git mv a renamed &&
+		test_expect_code 1 git diff $option --cached
+	"
+done
+
+test_expect_success 'setup dirty subrepo' '
+	git reset --hard &&
+	test_create_repo subrepo &&
+	test_commit -C subrepo subrepo-file &&
+	test_tick &&
+	git add subrepo &&
+	git commit -m subrepo &&
+	test_commit -C subrepo another-subrepo-file
+'
+
+for option in --exit-code --quiet
+do
+	for submodule_format in diff log short
+	do
+		opts="$option --submodule=$submodule_format" &&
+		test_expect_success "git diff $opts returns 1 for dirty subrepo" "
+			test_expect_code 1 git diff $opts
+		"
+	done
+done
+
+test_done