ui-tree: add support for source-filter option

This new option is used to specify an external command which will be
executed when displaying blob content in the tree view. Blob content
will be written to STDIN of the filter and STDOUT from the filter
will be included verbatim in the html output from cgit. The file name
of the blob will be passed as the only argument to the filter command.

Signed-off-by: Lars Hjemli <hjemli@gmail.com>

ui-tree.c

@@ -15,13 +15,23 @@ char *curr_rev;
 char *match_path;
 int header = 0;
 
-static void print_text_buffer(char *buf, unsigned long size)
+static void print_text_buffer(const char *name, char *buf, unsigned long size)
 {
 	unsigned long lineno, idx;
 	const char *numberfmt =
 		"<a class='no' id='n%1$d' name='n%1$d' href='#n%1$d'>%1$d</a>\n";
 
 	html("<table summary='blob content' class='blob'>\n");
+	if (ctx.cfg.source_filter) {
+		html("<tr><td class='lines'><pre><code>");
+		ctx.cfg.source_filter->argv[1] = xstrdup(name);
+		cgit_open_filter(ctx.cfg.source_filter);
+		write(STDOUT_FILENO, buf, size);
+		cgit_close_filter(ctx.cfg.source_filter);
+		html("</code></pre></td></tr></table>\n");
+		return;
+	}
+
 	html("<tr><td class='linenumbers'><pre>");
 	idx = 0;
 	lineno = 0;
@@ -65,7 +75,7 @@ static void print_binary_buffer(char *buf, unsigned long size)
 	html("</table>\n");
 }
 
-static void print_object(const unsigned char *sha1, char *path)
+static void print_object(const unsigned char *sha1, char *path, const char *basename)
 {
 	enum object_type type;
 	char *buf;
@@ -93,7 +103,7 @@ static void print_object(const unsigned char *sha1, char *path)
 	if (buffer_is_binary(buf, size))
 		print_binary_buffer(buf, size);
 	else
-		print_text_buffer(buf, size);
+		print_text_buffer(basename, buf, size);
 }
 
 
@@ -213,7 +223,7 @@ static int walk_tree(const unsigned char *sha1, const char *base, int baselen,
 			ls_head();
 			return READ_TREE_RECURSIVE;
 		} else {
-			print_object(sha1, buffer);
+			print_object(sha1, buffer, pathname);
 			return 0;
 		}
 	}