html.c: add various strbuf and varadic helpers
This adds the fmtalloc helper, html_txtf, html_vtxtf, and html_attrf.
These takes a printf style format string like htmlf but escapes the
resulting string. The html_vtxtf variant takes a va_list whereas
html_txtf is variadic.
Signed-off-by: John Keeping <john@keeping.me.uk>
diff --git a/cgit.h b/cgit.h
index 7581cc1..7619cbb 100644
--- a/cgit.h
+++ b/cgit.h
@@ -327,6 +327,9 @@
__attribute__((format (printf,1,2)))
extern char *fmt(const char *format,...);
+__attribute__((format (printf,1,2)))
+extern char *fmtalloc(const char *format,...);
+
extern struct commitinfo *cgit_parse_commit(struct commit *commit);
extern struct taginfo *cgit_parse_tag(struct tag *tag);
extern void cgit_parse_url(const char *url);