git: add file mode verification to tests

Signed-off-by: Tonis Tiigi <[email protected]>

source/git/source_test.go

@@ -373,10 +373,21 @@ func testFetchByTag(t *testing.T, tag, expectedCommitSubject string, isAnnotated
 	require.NoError(t, err)
 	defer lm.Unmount()
 
+	st, err := os.Lstat(filepath.Join(dir, "subdir"))
+	require.NoError(t, err)
+
+	require.True(t, st.IsDir())
+	require.Equal(t, strconv.FormatInt(0755, 8), strconv.FormatInt(int64(st.Mode()&os.ModePerm), 8))
+
 	dt, err := os.ReadFile(filepath.Join(dir, "def"))
 	require.NoError(t, err)
 	require.Equal(t, "bar\n", string(dt))
 
+	st, err = os.Lstat(filepath.Join(dir, "def"))
+	require.NoError(t, err)
+
+	require.Equal(t, strconv.FormatInt(0644, 8), strconv.FormatInt(int64(st.Mode()&os.ModePerm), 8))
+
 	dt, err = os.ReadFile(filepath.Join(dir, "foo13"))
 	if hasFoo13File {
 		require.NoError(t, err)
@@ -692,7 +703,9 @@ func setupGitRepo(t *testing.T) gitRepoFixture {
 		"git commit -m initial",
 		"git tag --no-sign a/v1.2.3",
 		"echo bar > def",
-		"git add def",
+		"mkdir subdir",
+		"echo subcontents > subdir/subfile",
+		"git add def subdir",
 		"git commit -m second",
 		"git tag -a -m \"this is an annotated tag\" v1.2.3",
 		"echo foo > bar",

source/git/source_unix_test.go

@@ -0,0 +1,11 @@
+//go:build !windows
+// +build !windows
+
+package git
+
+import "syscall"
+
+func init() {
+	// Reset umask to zero to match buildkitd and to make sure the tests do not rely on standard umask from the host.
+	syscall.Umask(0)
+}