From e0af1edadf13bca525a52aa4d6a8dd69bce34fde Mon Sep 17 00:00:00 2001
From: Joey Yakimowich-Payne <jyapayne@pm.me>
Date: Fri, 13 Mar 2026 21:27:08 -0600
Subject: [PATCH] fix: safety valve only flushes partial openers, not real tags
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Long cleanup tags (e.g. collapse summaries) can span 30+ SSE deltas.
The safety valve was flushing after 6 deltas regardless, dumping
incomplete tags into the output. Now only flushes when buffering a
partial opener (<m, <y) that never resolved — never when inside a
confirmed tag.
---
 src/mnemosyne/gateway.py | 13 ++++++++++---
 1 file changed, 10 insertions(+), 3 deletions(-)

diff --git a/src/mnemosyne/gateway.py b/src/mnemosyne/gateway.py
index e8057de..44591e0 100644
--- a/src/mnemosyne/gateway.py
+++ b/src/mnemosyne/gateway.py
@@ -220,9 +220,16 @@ class SSECleanupFilter:
         has_close = bool(_TAG_CLOSE_RE.search(self._buf))
         partial = _has_partial_tag(self._buf)
 
-        # Safety valve: if we've buffered too many deltas without resolving
-        # a tag, this is just prose containing '<' — flush everything.
-        if self._buffered_deltas > self._MAX_BUFFERED_DELTAS and not has_close:
+        # Safety valve: if we've buffered many deltas waiting for a *partial*
+        # opener to resolve (e.g. "<m" that turned out to be prose "<model>"),
+        # flush everything.  But NEVER flush when _inside_tag is True — that
+        # means we matched a real opening tag and are waiting for the close.
+        # Real tags (e.g. long collapse summaries) can span 30+ deltas.
+        if (
+            self._buffered_deltas > self._MAX_BUFFERED_DELTAS
+            and not self._inside_tag
+            and not has_close
+        ):
             result = self._buf
             self._buf = ""
             self._inside_tag = False