fix(telegram): guard rich details math crash (#46102)

gateway/platforms/telegram.py

@@ -953,6 +953,32 @@ class TelegramAdapter(BasePlatformAdapter):
         """
         return inspect.iscoroutinefunction(getattr(self._bot, "do_api_request", None))
 
+    _RICH_DETAILS_RE = re.compile(r"<details\b[^>]*>.*?</details>", re.IGNORECASE | re.DOTALL)
+    _RICH_MATH_IN_DETAILS_RE = re.compile(
+        r"(\$\$.*?\$\$|"
+        r"\\\[.*?\\\]|"
+        r"\\\(.*?\\\)|"
+        r"\\(?:sum|frac|alpha|beta|gamma|delta|theta|lambda|mu|pi|sigma|"
+        r"int|prod|sqrt|lim|infty|begin\{(?:equation|align|matrix|cases)\}))",
+        re.IGNORECASE | re.DOTALL,
+    )
+
+    def _has_telegram_desktop_details_math_crash_shape(self, content: str) -> bool:
+        """Return True for rich-message details+math content that crashes TDesktop.
+
+        Telegram Desktop 6.9.1 can crash while rendering Bot API 10.1 rich
+        messages containing math inside a collapsible details block
+        (telegramdesktop/tdesktop#30808). The Bot API accepts the payload, so
+        Hermes must skip rich delivery up front and use the legacy MarkdownV2
+        path until affected Desktop clients age out.
+        """
+        if not content:
+            return False
+        for details_block in self._RICH_DETAILS_RE.findall(content):
+            if self._RICH_MATH_IN_DETAILS_RE.search(details_block):
+                return True
+        return False
+
     def _should_attempt_rich(
         self, content: str, metadata: Optional[Dict[str, Any]] = None
     ) -> bool:
@@ -962,6 +988,7 @@ class TelegramAdapter(BasePlatformAdapter):
             and not (metadata or {}).get("expect_edits")
             and content
             and content.strip()
+            and not self._has_telegram_desktop_details_math_crash_shape(content)
             and self._content_fits_rich_limits(content)
             and self._bot_supports_rich()
         )
@@ -1194,6 +1221,7 @@ class TelegramAdapter(BasePlatformAdapter):
             and not getattr(self, "_rich_draft_disabled", False)
             and content
             and content.strip()
+            and not self._has_telegram_desktop_details_math_crash_shape(content)
             and self._content_fits_rich_limits(content)
             and self._bot_supports_rich()
         )

tests/gateway/test_telegram_rich_messages.py

@@ -24,6 +24,12 @@ from telegram.error import BadRequest, NetworkError, TimedOut
 # Content exercising rich-only constructs: a heading, a real Markdown table,
 # and a task list. Pipes / brackets must survive untouched into the payload.
 RICH_CONTENT = "## Results\n\n| Case | Status |\n|---|---|\n| rich | ✅ |\n\n- [x] table renders"
+DANGEROUS_DETAILS_MATH = (
+    "<details><summary>Complex proof</summary>\n\n"
+    "$$\\sum_{i=1}^{n} i = \\frac{n(n+1)}{2}$$\n\n"
+    "And inline \\(\\alpha + \\beta\\)\n"
+    "</details>"
+)
 
 # PTB 22.6's real unknown-endpoint errors: do_api_request can raise
 # EndPointNotFound for Bot API 404s, and the request layer can wrap that same
@@ -105,6 +111,48 @@ async def test_rich_happy_path_sends_raw_markdown():
     adapter._bot.send_message.assert_not_called()
 
 
+@pytest.mark.asyncio
+async def test_details_with_math_skips_rich_send_to_avoid_tdesktop_crash():
+    adapter = _make_adapter()
+
+    result = await adapter.send("12345", DANGEROUS_DETAILS_MATH)
+
+    assert result.success is True
+    bot = adapter._bot
+    assert bot is not None
+    bot.do_api_request.assert_not_called()
+    bot.send_message.assert_awaited()
+
+
+@pytest.mark.asyncio
+async def test_details_without_math_still_uses_rich_send():
+    adapter = _make_adapter()
+
+    result = await adapter.send(
+        "12345",
+        "<details><summary>Notes</summary>\nNo equations here.\n</details>",
+    )
+
+    assert result.success is True
+    bot = adapter._bot
+    assert bot is not None
+    bot.do_api_request.assert_awaited_once()
+    bot.send_message.assert_not_called()
+
+
+@pytest.mark.asyncio
+async def test_math_outside_details_still_uses_rich_send():
+    adapter = _make_adapter()
+
+    result = await adapter.send("12345", "Outside details: $$x^2 + y^2$$")
+
+    assert result.success is True
+    bot = adapter._bot
+    assert bot is not None
+    bot.do_api_request.assert_awaited_once()
+    bot.send_message.assert_not_called()
+
+
 @pytest.mark.asyncio
 async def test_rich_messages_opt_out_uses_legacy_send_path():
     adapter = _make_adapter(extra={"rich_messages": False})
@@ -393,6 +441,20 @@ async def test_rich_gate_tolerates_minimal_bot_without_raw_endpoint():
 # ── Streaming drafts: sendRichMessageDraft ─────────────────────────────
 
 
+@pytest.mark.asyncio
+async def test_details_with_math_skips_rich_draft_to_avoid_tdesktop_crash():
+    adapter = _make_adapter()
+    bot = adapter._bot
+    assert bot is not None
+    bot.do_api_request = AsyncMock(return_value=True)
+
+    result = await adapter.send_draft("12345", draft_id=7, content=DANGEROUS_DETAILS_MATH)
+
+    assert result.success is True
+    bot.do_api_request.assert_not_called()
+    bot.send_message_draft.assert_awaited_once()
+
+
 @pytest.mark.asyncio
 async def test_rich_draft_happy_path_sends_raw_markdown():
     adapter = _make_adapter()