ui-blame: Allow syntax highlighting

Place file contents into a single block so that syntax highlighting can
be applied in the usual fashion.  Place the alternating color bars
behind the file contents.  Force the default syntax highlighting
background to transparent.

Signed-off-by: Jeff Smith <whydoubt@gmail.com>
Reviewed-by: John Keeping <john@keeping.me.uk>

cgit.css

@@ -353,6 +353,16 @@ div#cgit table.blame div.alt:nth-child(odd) {
 	background: white;
 }
 
+div#cgit table.blame td.lines > div {
+	position: relative;
+}
+
+div#cgit table.blame td.lines > div > pre {
+	padding: 0 0 0 0.5em;
+	position: absolute;
+	top: 0;
+}
+
 div#cgit table.bin-blob {
 	margin-top: 0.5em;
 	border: solid 1px black;

filters/syntax-highlighting.py

@@ -34,7 +34,7 @@ sys.stdin = io.TextIOWrapper(sys.stdin.buffer, encoding='utf-8', errors='replace
 sys.stdout = io.TextIOWrapper(sys.stdout.buffer, encoding='utf-8', errors='replace')
 data = sys.stdin.read()
 filename = sys.argv[1]
-formatter = HtmlFormatter(style='pastie')
+formatter = HtmlFormatter(style='pastie', nobackground=True)
 
 try:
 	lexer = guess_lexer_for_filename(filename, data)

ui-blame.c

@@ -67,15 +67,29 @@ static void emit_blame_entry_linenumber(struct blame_entry *ent)
 		htmlf(numberfmt, ++lineno);
 }
 
-static void emit_blame_entry_line(struct blame_scoreboard *sb,
+static void emit_blame_entry_line_background(struct blame_scoreboard *sb,
 					     struct blame_entry *ent)
 {
-	const char *cp, *cpend;
+	unsigned long line;
+	size_t len, maxlen = 2;
+	const char* pos, *endpos;
 
-	cp = blame_nth_line(sb, ent->lno);
-	cpend = blame_nth_line(sb, ent->lno + ent->num_lines);
+	for (line = ent->lno; line < ent->lno + ent->num_lines; line++) {
+		html("\n");
+		pos = blame_nth_line(sb, line);
+		endpos = blame_nth_line(sb, line + 1);
+		len = 0;
+		while (pos < endpos) {
+			len++;
+			if (*pos++ == '\t')
+				len = (len + 7) & ~7;
+		}
+		if (len > maxlen)
+			maxlen = len;
+	}
 
-	html_ntxt(cp, cpend - cp);
+	for (len = 0; len < maxlen - 1; len++)
+		html(" ");
 }
 
 struct walk_tree_context {
@@ -88,6 +102,7 @@ static void print_object(const unsigned char *sha1, const char *path,
 			 const char *basename, const char *rev)
 {
 	enum object_type type;
+	char *buf;
 	unsigned long size;
 	struct argv_array rev_argv = ARGV_ARRAY_INIT;
 	struct rev_info revs;
@@ -102,6 +117,13 @@ static void print_object(const unsigned char *sha1, const char *path,
 		return;
 	}
 
+	buf = read_sha1_file(sha1, &type, &size);
+	if (!buf) {
+		cgit_print_error_page(500, "Internal server error",
+			"Error reading object %s", sha1_to_hex(sha1));
+		return;
+	}
+
 	argv_array_push(&rev_argv, "blame");
 	argv_array_push(&rev_argv, rev);
 	init_revisions(&revs, NULL);
@@ -157,20 +179,37 @@ static void print_object(const unsigned char *sha1, const char *path,
 		html("</td>\n");
 	}
 
-	/* Lines */
-	html("<td class='lines'>");
+	html("<td class='lines'><div>");
+
+	/* Colored bars behind lines */
+	html("<div>");
 	for (ent = sb.ent; ent; ) {
 		struct blame_entry *e = ent->next;
-		html("<div class='alt'><pre><code>");
-		emit_blame_entry_line(&sb, ent);
-		html("</code></pre></div>");
+		html("<div class='alt'><pre>");
+		emit_blame_entry_line_background(&sb, ent);
+		html("</pre></div>");
 		free(ent);
 		ent = e;
 	}
-	html("</td>\n");
+	html("</div>");
 
 	free((void *)sb.final_buf);
 
+	/* Lines */
+	html("<pre><code>");
+	if (ctx.repo->source_filter) {
+		char *filter_arg = xstrdup(basename);
+		cgit_open_filter(ctx.repo->source_filter, filter_arg);
+		html_raw(buf, size);
+		cgit_close_filter(ctx.repo->source_filter);
+		free(filter_arg);
+	} else {
+		html_txt(buf);
+	}
+	html("</code></pre>");
+
+	html("</div></td>\n");
+
 	html("</tr>\n</table>\n");
 
 	cgit_print_layout_end();