From 88f9fe8909aff4af13f02abee6e18355c8146cd9 Mon Sep 17 00:00:00 2001
From: Aleksa Sarai <cyphar@cyphar.com>
Date: Wed, 5 Jun 2024 01:02:17 +1000
Subject: [PATCH] fixup! contenthash: switch recursive rootPath implementation
 to be iterative

Signed-off-by: Aleksa Sarai <cyphar@cyphar.com>
---
 cache/contenthash/path_test.go | 45 ++++++++++++++++++++++++++++------
 1 file changed, 38 insertions(+), 7 deletions(-)

diff --git a/cache/contenthash/path_test.go b/cache/contenthash/path_test.go
index 6b11ac13e92a4..a6d895a5f15e8 100644
--- a/cache/contenthash/path_test.go
+++ b/cache/contenthash/path_test.go
@@ -3,7 +3,9 @@ package contenthash
 import (
 	"fmt"
 	"os"
+	"path"
 	"path/filepath"
+	"runtime"
 	"testing"
 
 	"github.com/stretchr/testify/require"
@@ -26,8 +28,8 @@ func TestRootPathSymlinks(t *testing.T) {
 	symlink(t, tmpdir, "link1/notaloop", "../target")
 	symlink(t, tmpdir, "link1/final", "/target")
 	//  |- link2
-	//     |- link1 -> /link1/./
-	//     |- link1sub -> /link1/sub/./
+	//     |- link1 -> /link1/
+	//     |- link1sub -> /link1/sub/
 	//     |- notaloop -> ./link1sub/../notaloop
 	//     |- notaloop_abs -> /link2/link1sub/../notaloop
 	//     |- notaloop2 -> ./link1/../link1/notaloop
@@ -37,8 +39,8 @@ func TestRootPathSymlinks(t *testing.T) {
 	//     |- target2 -> ./link1/../link1/final
 	//     |- target2_abs -> /link2/link1/../link1/final
 	mkdirAll(t, tmpdir, "link2")
-	symlink(t, tmpdir, "link2/link1sub", "/link1/sub/")
 	symlink(t, tmpdir, "link2/link1", "/link1/")
+	symlink(t, tmpdir, "link2/link1sub", "/link1/sub/")
 	symlink(t, tmpdir, "link2/notaloop", "./link1sub/../notaloop")
 	symlink(t, tmpdir, "link2/notaloop_abs", "/link2/link1sub/../notaloop")
 	symlink(t, tmpdir, "link2/notaloop2", "./link1/../link1/notaloop")
@@ -109,21 +111,50 @@ func TestRootPathSymlinks(t *testing.T) {
 			resolvedPath, err := rootPath(tmpdir, test.path, test.followTrailing, nil)
 			require.NoError(t, err)
 
-			expectedPath := filepath.Join(tmpdir, test.expected)
+			expectedPath := filepath.Join(tmpdir, filepath.FromSlash(test.expected))
 			require.Equal(t, expectedPath, resolvedPath)
 		})
 	}
 }
 
 func mkdirAll(t *testing.T, root, path string) {
+	path = filepath.FromSlash(path)
+
 	err := os.MkdirAll(filepath.Join(root, path), 0755)
 	require.NoError(t, err)
 }
 
-func symlink(t *testing.T, root, path, target string) {
-	dir, _ := filepath.Split(path)
+func symlink(t *testing.T, root, linkname, target string) {
+	linkname = filepath.FromSlash(linkname)
+
+	// We need to add a dummy drive letter to emulate absolute symlinks on
+	// Windows.
+	if runtime.GOOS == "windows" && path.IsAbs(target) {
+		target = "Z:" + filepath.FromSlash(target)
+	} else {
+		target = filepath.FromSlash(target)
+	}
+
+	dir, _ := filepath.Split(linkname)
 	mkdirAll(t, root, dir)
 
-	err := os.Symlink(target, filepath.Join(root, path))
+	fullLinkname := filepath.Join(root, linkname)
+
+	err := os.Symlink(target, fullLinkname)
 	require.NoError(t, err)
+
+	// Windows seems to automatically change our /foo/../bar symlinks to /bar,
+	// causing some tests to fail. Technically we only care about this symlink
+	// behaviour on Linux (since we implemented it this way to keep Linux
+	// compatibility), so if our symlink has the wrong target we can just skip
+	// the test.
+	actualTarget, err := os.Readlink(fullLinkname)
+	require.NoError(t, err)
+	if actualTarget != target {
+		fn := t.Skipf
+		if runtime.GOOS != "windows" {
+			fn = t.Fatalf
+		}
+		fn("created link had the wrong contents -- %s -> %s", target, actualTarget)
+	}
 }