3 files changed, 63 insertions, 5 deletions

diff --git a/libgo/go/path/filepath/path_test.go b/libgo/go/path/filepath/path_test.go
index 87cb5e5..b876658 100644
--- a/libgo/go/path/filepath/path_test.go
+++ b/libgo/go/path/filepath/path_test.go
@@ -814,6 +814,7 @@ type VolumeNameTest struct {
 var volumenametests = []VolumeNameTest{
 	{`c:/foo/bar`, `c:`},
 	{`c:`, `c:`},
+	{`2:`, ``},
 	{``, ``},
 	{`\\\host`, ``},
 	{`\\\host\`, ``},
@@ -845,3 +846,26 @@ func TestVolumeName(t *testing.T) {
 		}
 	}
 }
+
+func TestDriveLetterInEvalSymlinks(t *testing.T) {
+	if runtime.GOOS != "windows" {
+		return
+	}
+	wd, _ := os.Getwd()
+	if len(wd) < 3 {
+		t.Errorf("Current directory path %q is too short", wd)
+	}
+	lp := strings.ToLower(wd)
+	up := strings.ToUpper(wd)
+	flp, err := filepath.EvalSymlinks(lp)
+	if err != nil {
+		t.Fatalf("EvalSymlinks(%q) failed: %q", lp, err)
+	}
+	fup, err := filepath.EvalSymlinks(up)
+	if err != nil {
+		t.Fatalf("EvalSymlinks(%q) failed: %q", up, err)
+	}
+	if flp != fup {
+		t.Errorf("Results of EvalSymlinks do not match: %q and %q", flp, fup)
+	}
+}
diff --git a/libgo/go/path/filepath/path_windows.go b/libgo/go/path/filepath/path_windows.go
index 1d1d23b..3dcd030 100644
--- a/libgo/go/path/filepath/path_windows.go
+++ b/libgo/go/path/filepath/path_windows.go
@@ -35,9 +35,7 @@ func VolumeName(path string) (v string) {
 	}
 	// with drive letter
 	c := path[0]
-	if path[1] == ':' &&
-		('0' <= c && c <= '9' || 'a' <= c && c <= 'z' ||
-			'A' <= c && c <= 'Z') {
+	if path[1] == ':' && ('a' <= c && c <= 'z' || 'A' <= c && c <= 'Z') {
 		return path[:2]
 	}
 	// is it UNC
diff --git a/libgo/go/path/filepath/symlink_windows.go b/libgo/go/path/filepath/symlink_windows.go
index afa88bf..1ee9399 100644
--- a/libgo/go/path/filepath/symlink_windows.go
+++ b/libgo/go/path/filepath/symlink_windows.go
@@ -8,7 +8,24 @@ import (
 	"syscall"
 )
 
-func evalSymlinks(path string) (string, error) {
+func toShort(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
+}
+
+func toLong(path string) (string, error) {
 	p := syscall.StringToUTF16(path)
 	b := p // GetLongPathName says we can reuse buffer
 	n, err := syscall.GetLongPathName(&p[0], &b[0], uint32(len(b)))
@@ -23,5 +40,24 @@ func evalSymlinks(path string) (string, error) {
 		}
 	}
 	b = b[:n]
-	return Clean(syscall.UTF16ToString(b)), nil
+	return syscall.UTF16ToString(b), nil
+}
+
+func evalSymlinks(path string) (string, error) {
+	p, err := toShort(path)
+	if err != nil {
+		return "", err
+	}
+	p, err = toLong(p)
+	if err != nil {
+		return "", err
+	}
+	// syscall.GetLongPathName does not change the case of the drive letter,
+	// but the result of EvalSymlinks must be unique, so we have
+	// EvalSymlinks(`c:\a`) == EvalSymlinks(`C:\a`).
+	// Make drive letter upper case.
+	if len(p) >= 2 && p[1] == ':' && 'a' <= p[0] && p[0] <= 'z' {
+		p = string(p[0]+'A'-'a') + p[1:]
+	}
+	return Clean(p), nil
 }