Add built-in syntax highlighting

Highlighting previously required a source filter shelling out to
something like Pygments. A configured source filter still takes
precedence, every character is preserved so the line gutter stays
aligned, and large files are skipped.

1 file changed, 8 insertions, 1 deletion

diff --git a/source/ui-tree.c b/source/ui-tree.c
index cbaca38..9181b1b 100644
--- a/source/ui-tree.c
+++ b/source/ui-tree.c
@@ -30,6 +30,7 @@ struct walk_tree_context {
 static void print_text_buffer(const char *name, char *buf, unsigned long size)
 {
 	unsigned long lineno, idx;
+	const char *ext;
 	const char *numberfmt = "<a id='n%1$d' href='#n%1$d'>%1$d</a>\n";
 
 	html("<table summary='blob content' class='blob'>\n");
@@ -64,7 +65,13 @@ static void print_text_buffer(const char *name, char *buf, unsigned long size)
 		return;
 	}
 
-	html("<td class='lines'><pre><code>");
+	/* No source filter is configured, so tag the code with its file
+	 * extension (or bare name, for Makefile and the like) and let
+	 * cgit.js highlight it client-side. */
+	ext = strrchr(name, '.');
+	html("<td class='lines'><pre><code data-lang='");
+	html_attr(ext && ext[1] ? ext + 1 : name);
+	html("'>");
 	html_txt(buf);
 	html("</code></pre></td></tr></table>\n");
 }