http: avoid crash when asked for multiple file ranges

R=adg
CC=golang-dev
https://golang.org/cl/4289076

diff --git a/src/pkg/http/fs.go b/src/pkg/http/fs.go
index 4ad680ccc314bdbd9948ca396f25deace3d4c3bc..8b5c4770c49b2fab5927eea67ed79b0f283640d8 100644 (file)
--- a/src/pkg/http/fs.go
+++ b/src/pkg/http/fs.go
@@ -154,7 +154,10 @@ func serveFile(w ResponseWriter, r *Request, name string, redirect bool) {
        // handle Content-Range header.
        // TODO(adg): handle multiple ranges
        ranges, err := parseRange(r.Header.Get("Range"), size)
-       if err != nil || len(ranges) > 1 {
+       if err == nil && len(ranges) > 1 {
+               err = os.ErrorString("multiple ranges not supported")
+       }
+       if err != nil {
                Error(w, err.String(), StatusRequestedRangeNotSatisfiable)
                return
        }