Use short path for LIMA_HOME on windows

pkg/store/dirnames/dirnames.go

@@ -5,6 +5,7 @@ import (
 	"fmt"
 	"os"
 	"path/filepath"
+	"runtime"
 
 	"github.com/lima-vm/lima/pkg/store/filenames"
 )
@@ -17,18 +18,33 @@ const DotLima = ".lima"
 // NOTE: We do not use `~/Library/Application Support/Lima` on macOS.
 // We use `~/.lima` so that we can have enough space for the length of the socket path,
 // which can be only 104 characters on macOS.
+//
+// NOTE: There are some issues when using "long names" on Windows.
+// We use "short names" here, so that it works with user names containing unicode etc.
+// They normally have 8+3 characters, with suffix.
 func LimaDir() (string, error) {
 	dir := os.Getenv("LIMA_HOME")
 	if dir == "" {
 		homeDir, err := os.UserHomeDir()
 		if err != nil {
 			return "", err
 		}
+		// on windows, 8.3 paths are needed by some tools like QEMU
+		if runtime.GOOS == "windows" {
+			homeDir, err = ShortPathName(homeDir)
+			if err != nil {
+				return "", err
+			}
+		}
 		dir = filepath.Join(homeDir, DotLima)
 	}
 	if _, err := os.Stat(dir); errors.Is(err, os.ErrNotExist) {
 		return dir, nil
 	}
+	// on windows, EvalSymlinks translates short paths back to long again
+	if runtime.GOOS == "windows" {
+		return dir, nil
+	}
 	realdir, err := filepath.EvalSymlinks(dir)
 	if err != nil {
 		return "", fmt.Errorf("cannot evaluate symlinks in %q: %w", dir, err)

pkg/store/dirnames/shortname_others.go

@@ -0,0 +1,9 @@
+//go:build !windows
+// +build !windows
+
+package dirnames
+
+// ShortPathName just returns the provided path.
+func ShortPathName(path string) (string, error) {
+	return path, nil
+}

pkg/store/dirnames/shortname_test.go

@@ -0,0 +1,37 @@
+package dirnames
+
+import (
+	"os"
+	"path/filepath"
+	"testing"
+
+	"gotest.tools/v3/assert"
+)
+
+// Note: can't use t.TempDir(), because it is _always_ long... <sigh>
+//       instead use os.TempDir(), something like `C:\users\anders\Temp`
+
+func TestShortPathNameShort(t *testing.T) {
+	d := os.TempDir()
+	l := filepath.Join(d, "foo")
+	err := os.Mkdir(l, 0755)
+	assert.NilError(t, err)
+	s, err := ShortPathName(l)
+	assert.NilError(t, err)
+	t.Logf("%s => %s", l, s)
+	os.RemoveAll(l)
+}
+
+func TestShortPathNameLong(t *testing.T) {
+	d := os.TempDir()
+	l := filepath.Join(d, "baaaaaaaaaar")
+	err := os.Mkdir(l, 0755)
+	assert.NilError(t, err)
+	s, err := ShortPathName(l)
+	assert.NilError(t, err)
+	t.Logf("%s => %s", l, s)
+	fi, err := os.Stat(s)
+	assert.NilError(t, err)
+	assert.Assert(t, fi.Mode().IsDir())
+	os.RemoveAll(l)
+}

pkg/store/dirnames/shortname_windows.go

@@ -0,0 +1,23 @@
+package dirnames
+
+import (
+	"syscall"
+)
+
+// ShortPathName return the short path name, when given a long path.
+func ShortPathName(path string) (string, error) {
+	p := syscall.StringToUTF16(path)
+	b := p // GetShortPathName says we can reuse buffer
+	n, err := syscall.GetShortPathName(&p[0], &b[0], uint32(len(b)))
+	if err != nil {
+		return "", err
+	}
+	if n > uint32(len(b)) {
+		b = make([]uint16, n)
+		n, err = syscall.GetShortPathName(&p[0], &b[0], uint32(len(b)))
+		if err != nil {
+			return "", err
+		}
+	}
+	return syscall.UTF16ToString(b), nil
+}