godoc: quiet log spam

Fixes #3191.
Sorry.

R=golang-dev, bradfitz
CC=golang-dev
https://golang.org/cl/5726059

src/cmd/godoc/dirtrees.go

@@ -69,13 +69,7 @@ func (b *treeBuilder) newDirTree(fset *token.FileSet, path, name string, depth i
 		}
 	}
 
-	list, err := fs.ReadDir(path)
-	if err != nil {
-		// newDirTree is called with a path that should be a package
-		// directory; errors here should not happen, but if they do,
-		// we want to know about them
-		log.Printf("ReadDir(%s): %s", path, err)
-	}
+	list, _ := fs.ReadDir(path)
 
 	// determine number of subdirectories and if there are package files
 	ndirs := 0

src/cmd/godoc/filesystem.go

@@ -400,6 +400,7 @@ func (ns nameSpace) ReadDir(path string) ([]os.FileInfo, error) {
 		haveName = map[string]bool{}
 		all      []os.FileInfo
 		err      error
+		first    []os.FileInfo
 	)
 
 	for _, m := range ns.resolve(path) {
@@ -411,6 +412,14 @@ func (ns nameSpace) ReadDir(path string) ([]os.FileInfo, error) {
 			continue
 		}
 
+		if dir == nil {
+			dir = []os.FileInfo{}
+		}
+
+		if first == nil {
+			first = dir
+		}
+
 		// If we don't yet have Go files in 'all' and this directory
 		// has some, add all the files from this directory.
 		// Otherwise, only add subdirectories.
@@ -434,6 +443,15 @@ func (ns nameSpace) ReadDir(path string) ([]os.FileInfo, error) {
 		}
 	}
 
+	// We didn't find any directories containing Go files.
+	// If some directory returned successfully, use that.
+	if len(all) == 0 && first != nil {
+		for _, d := range first {
+			haveName[d.Name()] = true
+			all = append(all, d)
+		}
+	}
+
 	// Built union.  Add any missing directories needed to reach mount points.
 	for old := range ns {
 		if hasPathPrefix(old, path) && old != path {

src/cmd/godoc/godoc.go

@@ -658,7 +658,6 @@ func serveDirectory(w http.ResponseWriter, r *http.Request, abspath, relpath str
 
 	list, err := fs.ReadDir(abspath)
 	if err != nil {
-		log.Printf("ReadDir: %s", err)
 		serveError(w, r, relpath, err)
 		return
 	}