enhance: test on Windows and fix what it found (#1348)

Adds a weekly and on-demand workflow that runs the cross-compiled tests on Windows Server 2025 Core in a [dockur/windows](https://github.com/dockur/windows) QEMU VM, and fixes the Windows bugs it found in host and UNC paths, env handling, shell quoting, post-task scripts, health checks, checkout, action symlinks, step summaries, Git client certificates and docker mode from a Windows host.

Host-mode steps now emit UTF-8, `bash` falls back to Git's bash instead of the WSL launcher, the runner can run as a native Windows service, steps can keep background helpers with `RUNNER_TRACKING_ID`, and Windows arm64 binaries are released.

Fixes: https://gitea.com/gitea/runner/issues/1339
Fixes: https://gitea.com/gitea/runner/issues/637
Fixes: https://gitea.com/gitea/runner/issues/1172
Fixes: https://gitea.com/gitea/runner/issues/347
Reviewed-on: https://gitea.com/gitea/runner/pulls/1348
Reviewed-by: bircni <[email protected]>

act/filecollector/file_collector.go

@@ -27,22 +27,25 @@ type Handler interface {
 }
 
 type TarCollector struct {
-	TarWriter *tar.Writer
-	UID       int
-	GID       int
-	DstDir    string
+	TarWriter  *tar.Writer
+	UID        int
+	GID        int
+	DstDir     string
+	Executable bool // Windows has no exec bit, so mark everything executable like docker build
 }
 
 func (tc TarCollector) WriteFile(fpath string, fi fs.FileInfo, linkName string, f io.Reader) error {
 	// create a new dir/file header
-	header, err := tar.FileInfoHeader(fi, linkName)
+	header, err := tar.FileInfoHeader(fi, filepath.ToSlash(linkName))
 	if err != nil {
 		return err
 	}
 
 	// update the name to correctly reflect the desired destination when untaring
 	header.Name = path.Join(tc.DstDir, fpath)
-	header.Mode = int64(fi.Mode())
+	if tc.Executable {
+		header.Mode = header.Mode&0o755 | 0o111
+	}
 	header.Uid = tc.UID
 	header.Gid = tc.GID
 

act/filecollector/file_collector_test.go

@@ -54,6 +54,7 @@ func TestCollectFilesKeepsWhatGitTracksOrDoesNotIgnore(t *testing.T) {
 	}
 	expected := map[string]string{".gitignore": "", "ign/tracked": "", "nested/kept": "", "renamed": "", "sub/.gitignore": "", "sub/kept": ""}
 	if runtime.GOOS != "windows" {
+		require.NoError(t, os.Chmod(filepath.Join(repoDir, "renamed"), 0o777|os.ModeSticky))
 		require.NoError(t, os.Symlink(".env", filepath.Join(repoDir, "test.env")))
 		expected["test.env"] = ".env"
 	}
@@ -69,6 +70,9 @@ func TestCollectFilesKeepsWhatGitTracksOrDoesNotIgnore(t *testing.T) {
 	for header, err := tr.Next(); err != io.EOF; header, err = tr.Next() {
 		require.NoError(t, err)
 		files[header.Name] = header.Linkname
+		if header.Name == "renamed" && runtime.GOOS != "windows" {
+			assert.Equal(t, int64(0o1777), header.Mode)
+		}
 	}
 	assert.Contains(t, files, ".git/HEAD")
 	maps.DeleteFunc(files, func(name, _ string) bool { return strings.Contains("/"+name, "/.git/") })