path/filepath: implement Match and Glob on windows

As discussed on golang-dev, windows will use
"\" as path separator. No escaping allowed.

R=golang-dev, r, mattn.jp, rsc, rogpeppe, bsiegert, r
CC=golang-dev
https://golang.org/cl/5825044

src/pkg/path/filepath/match.go

@@ -7,6 +7,7 @@ package filepath
 import (
 	"errors"
 	"os"
+	"runtime"
 	"sort"
 	"strings"
 	"unicode/utf8"
@@ -37,6 +38,9 @@ var ErrBadPattern = errors.New("syntax error in pattern")
 // The only possible returned error is ErrBadPattern, when pattern
 // is malformed.
 //
+// On Windows, escaping is disabled. Instead, '\\' is treated as
+// path separator.
+//
 func Match(pattern, name string) (matched bool, err error) {
 Pattern:
 	for len(pattern) > 0 {
@@ -95,9 +99,11 @@ Scan:
 	for i = 0; i < len(pattern); i++ {
 		switch pattern[i] {
 		case '\\':
-			// error check handled in matchChunk: bad pattern.
-			if i+1 < len(pattern) {
-				i++
+			if runtime.GOOS != "windows" {
+				// error check handled in matchChunk: bad pattern.
+				if i+1 < len(pattern) {
+					i++
+				}
 			}
 		case '[':
 			inrange = true
@@ -167,10 +173,12 @@ func matchChunk(chunk, s string) (rest string, ok bool, err error) {
 			chunk = chunk[1:]
 
 		case '\\':
-			chunk = chunk[1:]
-			if len(chunk) == 0 {
-				err = ErrBadPattern
-				return
+			if runtime.GOOS != "windows" {
+				chunk = chunk[1:]
+				if len(chunk) == 0 {
+					err = ErrBadPattern
+					return
+				}
 			}
 			fallthrough
 
@@ -191,7 +199,7 @@ func getEsc(chunk string) (r rune, nchunk string, err error) {
 		err = ErrBadPattern
 		return
 	}
-	if chunk[0] == '\\' {
+	if chunk[0] == '\\' && runtime.GOOS != "windows" {
 		chunk = chunk[1:]
 		if len(chunk) == 0 {
 			err = ErrBadPattern

src/pkg/path/filepath/match_test.go

@@ -7,6 +7,7 @@ package filepath_test
 import (
 	. "path/filepath"
 	"runtime"
+	"strings"
 	"testing"
 )
 
@@ -76,21 +77,26 @@ func errp(e error) string {
 }
 
 func TestMatch(t *testing.T) {
-	if runtime.GOOS == "windows" {
-		// XXX: Don't pass for windows.
-		return
-	}
 	for _, tt := range matchTests {
-		ok, err := Match(tt.pattern, tt.s)
+		pattern := tt.pattern
+		s := tt.s
+		if runtime.GOOS == "windows" {
+			if strings.Index(pattern, "\\") >= 0 {
+				// no escape allowed on windows.
+				continue
+			}
+			pattern = Clean(pattern)
+			s = Clean(s)
+		}
+		ok, err := Match(pattern, s)
 		if ok != tt.match || err != tt.err {
-			t.Errorf("Match(%#q, %#q) = %v, %q want %v, %q", tt.pattern, tt.s, ok, errp(err), tt.match, errp(tt.err))
+			t.Errorf("Match(%#q, %#q) = %v, %q want %v, %q", pattern, s, ok, errp(err), tt.match, errp(tt.err))
 		}
 	}
 }
 
 // contains returns true if vector contains the string s.
 func contains(vector []string, s string) bool {
-	s = ToSlash(s)
 	for _, elem := range vector {
 		if elem == s {
 			return true
@@ -109,18 +115,20 @@ var globTests = []struct {
 }
 
 func TestGlob(t *testing.T) {
-	if runtime.GOOS == "windows" {
-		// XXX: Don't pass for windows.
-		return
-	}
 	for _, tt := range globTests {
-		matches, err := Glob(tt.pattern)
+		pattern := tt.pattern
+		result := tt.result
+		if runtime.GOOS == "windows" {
+			pattern = Clean(pattern)
+			result = Clean(result)
+		}
+		matches, err := Glob(pattern)
 		if err != nil {
-			t.Errorf("Glob error for %q: %s", tt.pattern, err)
+			t.Errorf("Glob error for %q: %s", pattern, err)
 			continue
 		}
-		if !contains(matches, tt.result) {
-			t.Errorf("Glob(%#q) = %#v want %v", tt.pattern, matches, tt.result)
+		if !contains(matches, result) {
+			t.Errorf("Glob(%#q) = %#v want %v", pattern, matches, result)
 		}
 	}
 	for _, pattern := range []string{"no_match", "../*/no_match"} {