godoc: skip template wrapping for complete HTML files

demo at http://wreck:8080/doc/
click on go_talk-20100112.html

R=gri
CC=golang-dev
https://golang.org/cl/186137

lib/godoc/dirlist.html

@@ -18,7 +18,7 @@
 </tr>
 {.repeated section @}
 <tr>
-	<td align="left"><a href="{Name|html}">{Name|html}</a></td>
+	<td align="left"><a href="{Name|html}{@|dir/}">{Name|html}{@|dir/}</a></td>
 	<td></td>
 	<td align="right">{Size|html}</td>
 	<td></td>

src/cmd/godoc/godoc.go

@@ -694,6 +694,14 @@ func timeFmt(w io.Writer, x interface{}, format string) {
 }
 
 
+// Template formatter for "dir/" format.
+func dirslashFmt(w io.Writer, x interface{}, format string) {
+	if x.(*os.Dir).IsDirectory() {
+		w.Write([]byte{'/'})
+	}
+}
+
+
 var fmap = template.FormatterMap{
 	"": textFmt,
 	"html": htmlFmt,
@@ -705,6 +713,7 @@ var fmap = template.FormatterMap{
 	"infoSnippet": infoSnippetFmt,
 	"padding": paddingFmt,
 	"time": timeFmt,
+	"dir/": dirslashFmt,
 }
 
 
@@ -802,6 +811,13 @@ func serveHTMLDoc(c *http.Conn, r *http.Request, path string) {
 		return
 	}
 
+	// if it begins with "<!DOCTYPE " assume it is standalone
+	// html that doesn't need the template wrapping.
+	if bytes.HasPrefix(src, strings.Bytes("<!DOCTYPE ")) {
+		c.Write(src)
+		return
+	}
+
 	// if it's the language spec, add tags to EBNF productions
 	if strings.HasSuffix(path, "go_spec.html") {
 		var buf bytes.Buffer
@@ -917,6 +933,12 @@ func serveDirectory(c *http.Conn, r *http.Request, path string) {
 		return
 	}
 
+	for _, d := range list {
+		if d.IsDirectory() {
+			d.Size = 0
+		}
+	}
+
 	var buf bytes.Buffer
 	if err := dirlistHTML.Execute(list, &buf); err != nil {
 		log.Stderrf("dirlistHTML.Execute: %s", err)