Split trailers out of the commit message

1 file changed, 125 insertions, 3 deletions

diff --git a/source/ui-commit.c b/source/ui-commit.c
index 6055509..b67f5db 100644
--- a/source/ui-commit.c
+++ b/source/ui-commit.c
@@ -18,6 +18,9 @@
 #include "ui-log.h"
 #include "ui-shared.h"
 
+#include <list.h>
+#include <trailer.h>
+
 // The diff below the message is always taken against the first parent alone,
 // which says little about a merge of many branches, so a commit with this
 // many parents or more is shown without a diff at all.
@@ -76,6 +79,127 @@ static void print_filtered_text(const char *text)
 	cgit_close_filter(ctx.repo->commit_filter);
 }
 
+/*
+ * A value shaped like an ident is written the way the author row is, through
+ * the email filter. Anything else goes through the trailer filter when one is
+ * set, and otherwise through the commit filter, so the links a site already
+ * draws in message text keep appearing on trailer lines.
+ */
+static void print_trailer_value(const char *key, const char *value)
+{
+	struct ident_split ident;
+	struct strbuf name = STRBUF_INIT, email = STRBUF_INIT;
+
+	if (!split_ident_line(&ident, value, strlen(value)) &&
+		memchr(ident.mail_begin, '@', ident.mail_end - ident.mail_begin)) {
+		strbuf_add(&name, ident.name_begin, ident.name_end - ident.name_begin);
+		strbuf_addch(&email, '<');
+		strbuf_add(&email, ident.mail_begin, ident.mail_end - ident.mail_begin);
+		strbuf_addch(&email, '>');
+		cgit_open_filter(ctx.repo->email_filter, email.buf, "commit");
+		html_txt(name.buf);
+		if (ctx.cfg.enable_plain_email) {
+			html(" ");
+			html_txt(email.buf);
+		}
+		cgit_close_filter(ctx.repo->email_filter);
+		strbuf_release(&name);
+		strbuf_release(&email);
+	} else if (ctx.repo->trailer_filter) {
+		cgit_open_filter(ctx.repo->trailer_filter, key, "commit");
+		html_txt(value);
+		cgit_close_filter(ctx.repo->trailer_filter);
+	} else
+		print_filtered_text(value);
+}
+
+/*
+ * One row per trailer, except that a run of trailers sharing a key becomes a
+ * single row listing every value. A line git kept in the block without being
+ * able to split it, such as a cherry-pick note, gets a row of its own.
+ */
+static void print_trailers(const char *msg)
+{
+	struct trailer_iterator iter;
+	struct strbuf key = STRBUF_INIT;
+	int open = 0;
+
+	html("<table class='commit-trailers'>\n");
+	trailer_iterator_init(&iter, msg);
+	while (trailer_iterator_advance(&iter)) {
+		if (!iter.val.len) {
+			if (open)
+				html("</td></tr>\n");
+			open = 0;
+			html("<tr><td colspan='2'>");
+			print_filtered_text(iter.key.buf);
+			html("</td></tr>\n");
+			continue;
+		}
+		if (open && !strcasecmp(key.buf, iter.key.buf))
+			html("<br>");
+		else {
+			if (open)
+				html("</td></tr>\n");
+			strbuf_reset(&key);
+			strbuf_addbuf(&key, &iter.key);
+			html("<tr><th>");
+			html_txt(key.buf);
+			html("</th><td>");
+			open = 1;
+		}
+		print_trailer_value(key.buf, iter.val.buf);
+	}
+	if (open)
+		html("</td></tr>\n");
+	html("</table>\n");
+	trailer_iterator_release(&iter);
+	strbuf_release(&key);
+}
+
+/*
+ * Git finds the trailer block by looking at the whole message, title included,
+ * so the subject goes back in front of the body before asking, and the offsets
+ * that come back are shifted by that prefix. The blank line that separated the
+ * body from its block is dropped along with the block.
+ */
+static void print_message(struct commitinfo *info)
+{
+	struct strbuf full = STRBUF_INIT;
+	struct process_trailer_options opts = PROCESS_TRAILER_OPTIONS_INIT;
+	struct trailer_block *block;
+	LIST_HEAD(items);
+	size_t prefix, start, end;
+	char *body = NULL;
+
+	if (ctx.repo->enable_trailers) {
+		strbuf_addf(&full, "%s\n\n%s", info->subject, info->msg);
+		prefix = full.len - strlen(info->msg);
+		opts.no_divider = 1;
+		block = parse_trailers(&opts, full.buf, &items);
+		start = trailer_block_start(block);
+		end = trailer_block_end(block);
+		free_trailers(&items);
+		trailer_block_release(block);
+		if (start >= prefix && start < end) {
+			size_t len = start - prefix;
+
+			while (len > 0 && info->msg[len - 1] == '\n')
+				len--;
+			body = xmemdupz(info->msg, len);
+		}
+	}
+
+	html("<div class='commit-msg'>");
+	print_filtered_text(body ? body : info->msg);
+	html("</div>\n");
+	if (body)
+		print_trailers(full.buf);
+
+	free(body);
+	strbuf_release(&full);
+}
+
 void cgit_print_commit(char *hex, const char *prefix)
 {
 	struct commit *commit;
@@ -145,9 +269,7 @@ void cgit_print_commit(char *hex, const char *prefix)
 	print_filtered_text(info->subject);
 	cgit_print_commit_decorations(commit);
 	html("</div>\n");
-	html("<div class='commit-msg'>");
-	print_filtered_text(info->msg);
-	html("</div>\n");
+	print_message(info);
 	if (notes.len != 0) {
 		html("<div class='notes-header'>Notes</div>\n");
 		html("<div class='notes'>");