command: allow using ASS tags on OSD messages

We don't allow this by default, because it would be silly if random
external data (like filenames or file tags) could accidentally trigger
them.

Add a property that magically disables this ASS tag escaping.

Note that malicious input could still disable ASS tag escaping by
itself. This would be annoying but harmless.

1 files changed, 12 insertions, 2 deletions

diff --git a/sub/osd_libass.c b/sub/osd_libass.c
index 1fea27ced6..03d5040dbf 100644
--- a/sub/osd_libass.c
+++ b/sub/osd_libass.c
@@ -159,8 +159,13 @@ void osd_get_function_sym(char *buffer, size_t buffer_size, int osd_function)
     snprintf(buffer, buffer_size, "\xFF%c", osd_function);
 }
 
+// Same trick as above: never valid UTF-8, so we expect it's free for use.
+const char *osd_ass_0 = "\xFD";
+const char *osd_ass_1 = "\xFE";
+
 static void mangle_ass(bstr *dst, const char *in)
 {
+    bool escape_ass = true;
     while (*in) {
         // As used by osd_get_function_sym().
         if (in[0] == '\xFF' && in[1]) {
@@ -170,11 +175,16 @@ static void mangle_ass(bstr *dst, const char *in)
             in += 2;
             continue;
         }
-        if (*in == '{')
+        if (*in == '\xFD' || *in == '\xFE') {
+            escape_ass = *in == '\xFE';
+            in += 1;
+            continue;
+        }
+        if (escape_ass && *in == '{')
             bstr_xappend(NULL, dst, bstr0("\\"));
         bstr_xappend(NULL, dst, (bstr){(char *)in, 1});
         // Break ASS escapes with U+2060 WORD JOINER
-        if (*in == '\\')
+        if (escape_ass && *in == '\\')
             mp_append_utf8_bstr(NULL, dst, 0x2060);
         in++;
     }