fix: clear fallback smd media tail

static/messages.js

@@ -4094,9 +4094,9 @@ function attachLiveStream(activeSid, streamId, uploaded=[], options={}){
     _smdParser=null;
     _smdWrittenLen=0;
     _smdWrittenText='';
-    // Clear the per-parser MEDIA tail buffer — any incomplete MEDIA
-    // prefix the parser was holding is no longer relevant.
-    if(typeof _smdMediaTailClear==='function') _smdMediaTailClear(null);
+    // Clear the fallback MEDIA tail buffer too; fallback chunks are keyed
+    // by __SMD_PARSER_FALLBACK, not null.
+    if(typeof _smdMediaTailClear==='function') _smdMediaTailClear(__SMD_PARSER_FALLBACK);
   }
   function _scheduleStreamingKatex(){
     if(_streamingKatexTimer) return;

tests/test_smd_media_in_stream.py

@@ -247,6 +247,15 @@ class TestSmdMediaInStream(unittest.TestCase):
             "concurrent streams don't cross-pollinate",
         )
 
+    def test_smd_end_parser_clears_fallback_media_tail(self):
+        # Greptile re-review: parserFor falls back to __SMD_PARSER_FALLBACK,
+        # so stream-end cleanup must clear that sentinel key, not null.
+        idx = MESSAGES_JS.index("function _smdEndParser")
+        block = MESSAGES_JS[idx:idx + 1200]
+        self.assertIn("_smdMediaTailClear(_smdParser)", block)
+        self.assertIn("_smdMediaTailClear(__SMD_PARSER_FALLBACK)", block)
+        self.assertNotIn("_smdMediaTailClear(null)", block)
+
 
 if __name__ == "__main__":
     import unittest