1 files changed, 22 insertions, 3 deletions
diff --git a/libgo/go/cmd/go/internal/str/path.go b/libgo/go/cmd/go/internal/str/path.go
index 84ca9d581e9..a9b4d759a6b 100644
--- a/libgo/go/cmd/go/internal/str/path.go
+++ b/libgo/go/cmd/go/internal/str/path.go
@@ -9,8 +9,25 @@ import (
 	"strings"
 )
 
-// HasFilePathPrefix reports whether the filesystem path s begins with the
-// elements in prefix.
+// HasPath reports whether the slash-separated path s
+// begins with the elements in prefix.
+func HasPathPrefix(s, prefix string) bool {
+	if len(s) == len(prefix) {
+		return s == prefix
+	}
+	if prefix == "" {
+		return true
+	}
+	if len(s) > len(prefix) {
+		if prefix[len(prefix)-1] == '/' || s[len(prefix)] == '/' {
+			return s[:len(prefix)] == prefix
+		}
+	}
+	return false
+}
+
+// HasFilePathPrefix reports whether the filesystem path s
+// begins with the elements in prefix.
 func HasFilePathPrefix(s, prefix string) bool {
 	sv := strings.ToUpper(filepath.VolumeName(s))
 	pv := strings.ToUpper(filepath.VolumeName(prefix))
@@ -23,8 +40,10 @@ func HasFilePathPrefix(s, prefix string) bool {
 		return false
 	case len(s) == len(prefix):
 		return s == prefix
+	case prefix == "":
+		return true
 	case len(s) > len(prefix):
-		if prefix != "" && prefix[len(prefix)-1] == filepath.Separator {
+		if prefix[len(prefix)-1] == filepath.Separator {
 			return strings.HasPrefix(s, prefix)
 		}
 		return s[len(prefix)] == filepath.Separator && s[:len(prefix)] == prefix