libgo, compiler: Upgrade libgo to Go 1.4, except for runtime.

This upgrades all of libgo other than the runtime package to
the Go 1.4 release.  In Go 1.4 much of the runtime was
rewritten into Go.  Merging that code will take more time and
will not change the API, so I'm putting it off for now.

There are a few runtime changes anyhow, to accomodate other
packages that rely on minor modifications to the runtime
support.

The compiler changes slightly to add a one-bit flag to each
type descriptor kind that is stored directly in an interface,
which for gccgo is currently only pointer types.  Another
one-bit flag (gcprog) is reserved because it is used by the gc
compiler, but gccgo does not currently use it.

There is another error check in the compiler since I ran
across it during testing.

gotools/:
	* Makefile.am (go_cmd_go_files): Sort entries.  Add generate.go.
	* Makefile.in: Rebuild.

From-SVN: r219627

1 files changed, 25 insertions, 18 deletions

diff --git a/libgo/go/net/http/fs.go b/libgo/go/net/http/fs.go
index 8576cf844a3..e322f710a5d 100644
--- a/libgo/go/net/http/fs.go
+++ b/libgo/go/net/http/fs.go
@@ -22,8 +22,12 @@ import (
 	"time"
 )
 
-// A Dir implements http.FileSystem using the native file
-// system restricted to a specific directory tree.
+// A Dir implements FileSystem using the native file system restricted to a
+// specific directory tree.
+//
+// While the FileSystem.Open method takes '/'-separated paths, a Dir's string
+// value is a filename on the native file system, not a URL, so it is separated
+// by filepath.Separator, which isn't necessarily '/'.
 //
 // An empty Dir is treated as ".".
 type Dir string
@@ -139,7 +143,7 @@ func serveContent(w ResponseWriter, r *Request, name string, modtime time.Time,
 	if checkLastModified(w, r, modtime) {
 		return
 	}
-	rangeReq, done := checkETag(w, r)
+	rangeReq, done := checkETag(w, r, modtime)
 	if done {
 		return
 	}
@@ -212,12 +216,6 @@ func serveContent(w ResponseWriter, r *Request, name string, modtime time.Time,
 			code = StatusPartialContent
 			w.Header().Set("Content-Range", ra.contentRange(size))
 		case len(ranges) > 1:
-			for _, ra := range ranges {
-				if ra.start > size {
-					Error(w, err.Error(), StatusRequestedRangeNotSatisfiable)
-					return
-				}
-			}
 			sendSize = rangesMIMESize(ranges, ctype, size)
 			code = StatusPartialContent
 
@@ -281,11 +279,14 @@ func checkLastModified(w ResponseWriter, r *Request, modtime time.Time) bool {
 }
 
 // checkETag implements If-None-Match and If-Range checks.
-// The ETag must have been previously set in the ResponseWriter's headers.
+//
+// The ETag or modtime must have been previously set in the
+// ResponseWriter's headers.  The modtime is only compared at second
+// granularity and may be the zero value to mean unknown.
 //
 // The return value is the effective request "Range" header to use and
 // whether this request is now considered done.
-func checkETag(w ResponseWriter, r *Request) (rangeReq string, done bool) {
+func checkETag(w ResponseWriter, r *Request, modtime time.Time) (rangeReq string, done bool) {
 	etag := w.Header().get("Etag")
 	rangeReq = r.Header.get("Range")
 
@@ -296,11 +297,17 @@ func checkETag(w ResponseWriter, r *Request) (rangeReq string, done bool) {
 	// We only support ETag versions.
 	// The caller must have set the ETag on the response already.
 	if ir := r.Header.get("If-Range"); ir != "" && ir != etag {
-		// TODO(bradfitz): handle If-Range requests with Last-Modified
-		// times instead of ETags? I'd rather not, at least for
-		// now. That seems like a bug/compromise in the RFC 2616, and
-		// I've never heard of anybody caring about that (yet).
-		rangeReq = ""
+		// The If-Range value is typically the ETag value, but it may also be
+		// the modtime date. See golang.org/issue/8367.
+		timeMatches := false
+		if !modtime.IsZero() {
+			if t, err := ParseTime(ir); err == nil && t.Unix() == modtime.Unix() {
+				timeMatches = true
+			}
+		}
+		if !timeMatches {
+			rangeReq = ""
+		}
 	}
 
 	if inm := r.Header.get("If-None-Match"); inm != "" {
@@ -378,7 +385,7 @@ func serveFile(w ResponseWriter, r *Request, fs FileSystem, name string, redirec
 
 	// use contents of index.html for directory, if present
 	if d.IsDir() {
-		index := name + indexPage
+		index := strings.TrimSuffix(name, "/") + indexPage
 		ff, err := fs.Open(index)
 		if err == nil {
 			defer ff.Close()
@@ -400,7 +407,7 @@ func serveFile(w ResponseWriter, r *Request, fs FileSystem, name string, redirec
 		return
 	}
 
-	// serverContent will check modification time
+	// serveContent will check modification time
 	sizeFunc := func() (int64, error) { return d.Size(), nil }
 	serveContent(w, r, d.Name(), d.ModTime(), sizeFunc, f)
 }