1 file changed, 39 insertions, 9 deletions
diff --git a/source/ui-summary.c b/source/ui-summary.c
index 947812a..7e533e1 100644
--- a/source/ui-summary.c
+++ b/source/ui-summary.c
@@ -99,6 +99,17 @@ static char* append_readme_path(const char *filename, const char *ref, const cha
 	return full_path;
 }
 
+static int readme_is_markdown(const char *filename)
+{
+	const char *ext = strrchr(filename, '.');
+
+	if (!ext || !ext[1])
+		return 0;
+	ext++;
+	return !strcasecmp(ext, "md") || !strcasecmp(ext, "markdown") ||
+	       !strcasecmp(ext, "mkd") || !strcasecmp(ext, "mdown");
+}
+
 void cgit_print_repo_readme(const char *path)
 {
 	char *filename, *ref, *mimetype;
@@ -128,16 +139,35 @@ void cgit_print_repo_readme(const char *path)
 			goto done;
 	}
 
-	/* Print the calculated readme, either from the git repo or from the
-	 * filesystem, while applying the about-filter.
-	 */
 	html("<div id='summary'>");
-	cgit_open_filter(ctx.repo->about_filter, filename);
-	if (ref)
-		cgit_print_file(filename, ref, 1);
-	else
-		html_include(filename);
-	cgit_close_filter(ctx.repo->about_filter);
+	if (!ctx.repo->about_filter && ctx.cfg.enable_markdown &&
+	    readme_is_markdown(filename)) {
+		/* No about-filter is set, so hand the markdown source to the
+		 * built-in client-side renderer in cgit.js. The source is
+		 * escaped here and rendered in the browser, and it degrades to
+		 * readable plain text when scripting is off.
+		 */
+		html("<div class='markdown' data-markdown>");
+		if (ref) {
+			cgit_print_file(filename, ref, 1, 1);
+		} else {
+			struct strbuf sb = STRBUF_INIT;
+			if (strbuf_read_file(&sb, filename, 0) >= 0)
+				html_txt(sb.buf);
+			strbuf_release(&sb);
+		}
+		html("</div>");
+	} else {
+		/* Otherwise print the readme through the about-filter, or raw
+		 * when none is configured.
+		 */
+		cgit_open_filter(ctx.repo->about_filter, filename);
+		if (ref)
+			cgit_print_file(filename, ref, 1, 0);
+		else
+			html_include(filename);
+		cgit_close_filter(ctx.repo->about_filter);
+	}
 
 	html("</div>");
 	if (free_filename)