stage-batch11: #3330 pinned-scroll + #3311 inline-math currency

#3330 Fix pinned chat scroll after message rebuild
Co-authored-by: jianongHe <jianongHe@users.noreply.github.com>

#3311 fix: reject inline math when $ is followed by a digit (currency)
Co-authored-by: toanalien <toanalien@users.noreply.github.com>

static/ui.js

@@ -2758,13 +2758,24 @@ function _setMessageScrollToBottom(){
   _lastScrollTop=el.scrollTop;
   _nearBottomCount=2;
   _scrollPinned=true;
-  requestAnimationFrame(()=>{ setTimeout(()=>{_programmaticScroll=false;},0); });
+  requestAnimationFrame(()=>{
+    el.scrollTop=el.scrollHeight;
+    _lastScrollTop=el.scrollTop;
+    _nearBottomCount=2;
+    _scrollPinned=true;
+    requestAnimationFrame(()=>{ setTimeout(()=>{_programmaticScroll=false;},0); });
+  });
 }
 function _isMessagePaneNearBottom(threshold=250){
   const el=$('messages');
   if(!el) return false;
   return el.scrollHeight-el.scrollTop-el.clientHeight<=threshold;
 }
+function _messageBottomDistance(){
+  const el=$('messages');
+  if(!el) return 0;
+  return el.scrollHeight-el.scrollTop-el.clientHeight;
+}
 function _shouldFollowMessagesOnDomReplace(){
   return !_messageUserUnpinned && (_scrollPinned || _isMessagePaneNearBottom(1200));
 }
@@ -2793,6 +2804,7 @@ function _settleMessageScrollToBottom(force){
 function scrollIfPinned(){
   if(!_scrollPinned) return;
   if(_recentNonMessageScrollIntent()) return;
+  if(_messageBottomDistance()>500) _setMessageScrollToBottom();
   _settleMessageScrollToBottom(false);
 }
 function scrollToBottom(){
@@ -3098,9 +3110,10 @@ function renderMd(raw){
   s=s.replace(/\$\$([\s\S]+?)\$\$/g,(_,m)=>{math_stash.push({type:'display',src:m});return '\x00M'+(math_stash.length-1)+'\x00';});
   // Match a single literal backslash before the display delimiter (the common LLM form).
   s=s.replace(/\\\[([\s\S]+?)\\\]/g,(_,m)=>{math_stash.push({type:'display',src:m});return '\x00M'+(math_stash.length-1)+'\x00';});
-  // Inline math: $...$ — require non-space at boundaries to avoid false positives
-  // e.g. "costs $5 and $10" should not trigger (space after opening $)
-  s=s.replace(/\$([^\s$\n][^$\n]*?[^\s$\n]|\S)\$/g,(_,m)=>{if(m.includes(' | '))return '\$'+m+'\$';math_stash.push({type:'inline',src:m});return '\x00M'+(math_stash.length-1)+'\x00';});
+  // Inline math: $...$ — require non-space/non-digit at opening boundary to avoid
+  // false positives on currency like "$1,000 xuống ~$95" or "costs $5 and $10".
+  // Aligns with smd's se() guard which also rejects $ followed by digits.
+  s=s.replace(/\$([^\s$\d\n][^$\n]*?[^\s$\n]|[^\s\d])\$/g,(_,m)=>{if(m.includes(' | '))return '\$'+m+'\$';math_stash.push({type:'inline',src:m});return '\x00M'+(math_stash.length-1)+'\x00';});
   // Also stash \(...\) LaTeX delimiters.
   // Match a single literal backslash before the delimiter (the common LLM form).
   s=s.replace(/\\\((.+?)\\\)/g,(_,m)=>{math_stash.push({type:'inline',src:m});return '\x00M'+(math_stash.length-1)+'\x00';});

tests/test_issue3319_pinned_scroll_jump.py

@@ -0,0 +1,39 @@
+"""Regression coverage for #3319: pinned chat should recover after DOM rebuilds."""
+from pathlib import Path
+
+ROOT = Path(__file__).resolve().parents[1]
+UI_JS = (ROOT / "static" / "ui.js").read_text(encoding="utf-8")
+
+
+def _extract_fn(src: str, name: str) -> str:
+    marker = f"function {name}"
+    start = src.find(marker)
+    assert start >= 0, f"{name} not found"
+    brace = src.find("{", start)
+    assert brace >= 0, f"{name} body not found"
+    depth = 0
+    for i in range(brace, len(src)):
+        ch = src[i]
+        if ch == "{":
+            depth += 1
+        elif ch == "}":
+            depth -= 1
+            if depth == 0:
+                return src[start : i + 1]
+    raise AssertionError(f"{name} body did not close")
+
+
+def test_scroll_to_bottom_retries_after_next_layout_frame():
+    fn = _extract_fn(UI_JS, "_setMessageScrollToBottom")
+    assert "el.scrollTop=el.scrollHeight;" in fn
+    assert "requestAnimationFrame(()=>{" in fn
+    assert fn.count("el.scrollTop=el.scrollHeight;") >= 2
+    assert fn.count("_lastScrollTop=el.scrollTop;") >= 2
+
+
+def test_scroll_if_pinned_recovers_when_far_from_bottom():
+    fn = _extract_fn(UI_JS, "scrollIfPinned")
+    assert "_messageBottomDistance()>500" in fn
+    assert "_setMessageScrollToBottom();" in fn
+    assert fn.index("_messageBottomDistance()>500") < fn.index("_settleMessageScrollToBottom(false)")
+

tests/test_issue347.py

@@ -429,6 +429,24 @@ def test_inline_math_regex_requires_non_space_boundaries():
         f"Inline math regex must exclude spaces at boundaries to prevent false "
         f"positives on currency like $5. Found: {inline_line[:120]}"
     )
+def test_inline_math_regex_rejects_digit_after_opening_dollar():
+    """The $...$ inline regex must reject $ followed by a digit.
+
+    Currency like '$1,000 xuống ~$95' must NOT be parsed as math.
+    The opening $ followed by a digit (0-9) is a strong currency signal.
+    Aligns with smd's se() guard which also rejects $ + digit.
+    """
+    inline_push_idx = UI_JS.find("type:'inline',src:m")
+    assert inline_push_idx != -1
+    line_start = UI_JS.rfind('\n', 0, inline_push_idx) + 1
+    inline_line = UI_JS[line_start:inline_push_idx + 50]
+    # The regex character class for the first char must exclude \d
+    assert '\\d' in inline_line, (
+        f"Inline math regex must exclude digits at opening boundary to prevent "
+        f"false positives on currency like $1,000. Found: {inline_line[:120]}"
+    )
+
+
 def test_display_math_stashed_before_inline():
     """$$...$$ display math must be stashed before $...$ inline math.