fix multiple readme file rendering and fix #1657 (#1658)

* fix multiple readme file rendering and fix #1657

* remove unnecessary loop

Author: lunny

modules/markup/markup.go

@@ -59,6 +59,15 @@ func Type(filename string) string {
 	return ""
 }
 
+// ReadmeFileType reports whether name looks like a README file
+// based on its name and find the parser via its ext name
+func ReadmeFileType(name string) (string, bool) {
+	if IsReadmeFile(name) {
+		return Type(name), true
+	}
+	return "", false
+}
+
 // IsReadmeFile reports whether name looks like a README file
 // based on its name.
 func IsReadmeFile(name string) bool {

routers/repo/view.go

@@ -56,13 +56,19 @@ func renderDirectory(ctx *context.Context, treeLink string) {
 
 	var readmeFile *git.Blob
 	for _, entry := range entries {
-		if entry.IsDir() || !markup.IsReadmeFile(entry.Name()) {
+		if entry.IsDir() {
+			continue
+		}
+
+		tp, ok := markup.ReadmeFileType(entry.Name())
+		if !ok {
 			continue
 		}
 
-		// TODO: collect all possible README files and show with priority.
 		readmeFile = entry.Blob()
-		break
+		if tp != "" {
+			break
+		}
 	}
 
 	if readmeFile != nil {