diff --git a/src/os/file_windows.go b/src/os/file_windows.go index 0d8c0fd20d..cc695fd94c 100644 --- a/src/os/file_windows.go +++ b/src/os/file_windows.go @@ -330,8 +330,18 @@ func Symlink(oldname, newname string) error { // need the exact location of the oldname when it's relative to determine if it's a directory destpath := oldname - if !isAbs(oldname) { - destpath = dirname(newname) + `\` + oldname + if v := volumeName(oldname); v == "" { + if len(oldname) > 0 && IsPathSeparator(oldname[0]) { + // oldname is relative to the volume containing newname. + if v = volumeName(newname); v != "" { + // Prepend the volume explicitly, because it may be different from the + // volume of the current working directory. + destpath = v + oldname + } + } else { + // oldname is relative to newname. + destpath = dirname(newname) + `\` + oldname + } } fi, err := Stat(destpath) diff --git a/src/os/os_windows_test.go b/src/os/os_windows_test.go index 8c14103143..f03ec750d0 100644 --- a/src/os/os_windows_test.go +++ b/src/os/os_windows_test.go @@ -965,9 +965,10 @@ func TestWindowsDevNullFile(t *testing.T) { // works on Windows when developer mode is active. // This is supported starting Windows 10 (1703, v10.0.14972). func TestSymlinkCreation(t *testing.T) { - if !isWindowsDeveloperModeActive() { + if !testenv.HasSymlink() && !isWindowsDeveloperModeActive() { t.Skip("Windows developer mode is not active") } + t.Parallel() temp, err := ioutil.TempDir("", "TestSymlinkCreation") if err != nil { @@ -1005,6 +1006,122 @@ func isWindowsDeveloperModeActive() bool { return val != 0 } +// TestRootRelativeDirSymlink verifies that symlinks to paths relative to the +// drive root (beginning with "\" but no volume name) are created with the +// correct symlink type. +// (See https://golang.org/issue/39183#issuecomment-632175728.) +func TestRootRelativeDirSymlink(t *testing.T) { + testenv.MustHaveSymlink(t) + t.Parallel() + + temp := t.TempDir() + dir := filepath.Join(temp, "dir") + if err := os.Mkdir(dir, 0755); err != nil { + t.Fatal(err) + } + + volumeRelDir := strings.TrimPrefix(dir, filepath.VolumeName(dir)) // leaves leading backslash + + link := filepath.Join(temp, "link") + err := os.Symlink(volumeRelDir, link) + if err != nil { + t.Fatal(err) + } + t.Logf("Symlink(%#q, %#q)", volumeRelDir, link) + + f, err := os.Open(link) + if err != nil { + t.Fatal(err) + } + defer f.Close() + if fi, err := f.Stat(); err != nil { + t.Fatal(err) + } else if !fi.IsDir() { + t.Errorf("Open(%#q).Stat().IsDir() = false; want true", f.Name()) + } +} + +// TestWorkingDirectoryRelativeSymlink verifies that symlinks to paths relative +// to the current working directory for the drive, such as "C:File.txt", are +// correctly converted to absolute links of the correct symlink type (per +// https://docs.microsoft.com/en-us/windows/win32/fileio/creating-symbolic-links). +func TestWorkingDirectoryRelativeSymlink(t *testing.T) { + testenv.MustHaveSymlink(t) + + // Construct a directory to be symlinked. + temp := t.TempDir() + if v := filepath.VolumeName(temp); len(v) < 2 || v[1] != ':' { + t.Skipf("Can't test relative symlinks: t.TempDir() (%#q) does not begin with a drive letter.", temp) + } + + absDir := filepath.Join(temp, `dir\sub`) + if err := os.MkdirAll(absDir, 0755); err != nil { + t.Fatal(err) + } + + // Change to the temporary directory and construct a + // working-directory-relative symlink. + oldwd, err := os.Getwd() + if err != nil { + t.Fatal(err) + } + defer func() { + if err := os.Chdir(oldwd); err != nil { + t.Fatal(err) + } + }() + if err := os.Chdir(temp); err != nil { + t.Fatal(err) + } + t.Logf("Chdir(%#q)", temp) + + wdRelDir := filepath.VolumeName(temp) + `dir\sub` // no backslash after volume. + absLink := filepath.Join(temp, "link") + err = os.Symlink(wdRelDir, absLink) + if err != nil { + t.Fatal(err) + } + t.Logf("Symlink(%#q, %#q)", wdRelDir, absLink) + + // Now change back to the original working directory and verify that the + // symlink still refers to its original path and is correctly marked as a + // directory. + if err := os.Chdir(oldwd); err != nil { + t.Fatal(err) + } + t.Logf("Chdir(%#q)", oldwd) + + resolved, err := os.Readlink(absLink) + if err != nil { + t.Errorf("Readlink(%#q): %v", absLink, err) + } else if resolved != absDir { + t.Errorf("Readlink(%#q) = %#q; want %#q", absLink, resolved, absDir) + } + + linkFile, err := os.Open(absLink) + if err != nil { + t.Fatal(err) + } + defer linkFile.Close() + + linkInfo, err := linkFile.Stat() + if err != nil { + t.Fatal(err) + } + if !linkInfo.IsDir() { + t.Errorf("Open(%#q).Stat().IsDir() = false; want true", absLink) + } + + absInfo, err := os.Stat(absDir) + if err != nil { + t.Fatal(err) + } + + if !os.SameFile(absInfo, linkInfo) { + t.Errorf("SameFile(Stat(%#q), Open(%#q).Stat()) = false; want true", absDir, absLink) + } +} + // TestStatOfInvalidName is regression test for issue #24999. func TestStatOfInvalidName(t *testing.T) { _, err := os.Stat("*.go")