fix(ui): use absolute keep_count for edit and regenerate truncate

Refs nesquena/hermes-webui#5096

Co-authored-by: b3nw <b3nw@users.noreply.github.com>

static/ui.js

@@ -14086,16 +14086,19 @@ function autoResizeTextarea(ta) {
 
 async function submitEdit(msgIdx, newText) {
   if(!S.session || S.busy) return;
-  // Truncate session at msgIdx (keep messages before the edited one)
-  // then re-send the edited text
+  const initialSid = S.session.session_id;
+  const absoluteKeepCount = _oldestIdx + msgIdx;
+  if(typeof _ensureAllMessagesLoaded==='function'){
+    await _ensureAllMessagesLoaded();
+  }
+  if(!S.session || S.session.session_id !== initialSid) return;
   try {
     await api('/api/session/truncate', {method:'POST', body:JSON.stringify({
-      session_id: S.session.session_id,
-      keep_count: msgIdx  // keep messages[0..msgIdx-1], discard from msgIdx onward
+      session_id: initialSid,
+      keep_count: absoluteKeepCount
     })});
-    S.messages = S.messages.slice(0, msgIdx);
+    S.messages = S.messages.slice(0, absoluteKeepCount);
     renderMessages();
-    // Now send the edited message as a new chat
     $('msg').value = newText;
     await send();
   } catch(e) { setStatus(t('edit_failed') + e.message); }
@@ -14103,24 +14106,27 @@ async function submitEdit(msgIdx, newText) {
 
 async function regenerateResponse(btn) {
   if(!S.session || S.busy) return;
-  // Find the last user message and re-run it
-  // Remove the last assistant message first (truncate to before it)
   const row = btn.closest('[data-msg-idx]');
   if(!row) return;
   const assistantIdx = parseInt(row.dataset.msgIdx, 10);
-  // Find the last user message text (one before this assistant message)
+  const absoluteKeepCount = _oldestIdx + assistantIdx;
+  const initialSid = S.session.session_id;
   let lastUserText = '';
   for(let i = assistantIdx - 1; i >= 0; i--) {
     const m = S.messages[i];
     if(m && m.role === 'user') { lastUserText = msgContent(m); break; }
   }
   if(!lastUserText) return;
+  if(typeof _ensureAllMessagesLoaded==='function'){
+    await _ensureAllMessagesLoaded();
+  }
+  if(!S.session || S.session.session_id !== initialSid) return;
   try {
     await api('/api/session/truncate', {method:'POST', body:JSON.stringify({
-      session_id: S.session.session_id,
-      keep_count: assistantIdx  // remove the assistant message
+      session_id: initialSid,
+      keep_count: absoluteKeepCount
     })});
-    S.messages = S.messages.slice(0, assistantIdx);
+    S.messages = S.messages.slice(0, absoluteKeepCount);
     renderMessages();
     $('msg').value = lastUserText;
     await send();

tests/test_issue_edit_regenerate_absolute_keep_count.py

@@ -0,0 +1,42 @@
+"""Regression: edit/regenerate use absolute keep_count (#2184 pattern)."""
+
+import re
+from pathlib import Path
+
+REPO = Path(__file__).resolve().parents[1]
+UI_JS = (REPO / "static" / "ui.js").read_text(encoding="utf-8")
+
+
+def _function_body(src: str, name: str) -> str:
+    needle_async = f"async function {name}"
+    start = src.index(needle_async)
+    brace = src.index("{", start)
+    depth = 0
+    for i in range(brace, len(src)):
+        if src[i] == "{":
+            depth += 1
+        elif src[i] == "}":
+            depth -= 1
+            if depth == 0:
+                return src[start : i + 1]
+    raise AssertionError(f"function {name!r} body not found")
+
+
+def test_submit_edit_uses_absolute_keep_count():
+    body = _function_body(UI_JS, "submitEdit")
+    assert re.search(r"absoluteKeepCount\s*=\s*_oldestIdx\s*\+\s*msgIdx", body)
+    assert "keep_count: absoluteKeepCount" in body
+
+
+def test_regenerate_uses_absolute_keep_count():
+    body = _function_body(UI_JS, "regenerateResponse")
+    assert re.search(r"absoluteKeepCount\s*=\s*_oldestIdx\s*\+\s*assistantIdx", body)
+    assert "keep_count: absoluteKeepCount" in body
+
+
+def test_submit_edit_captures_absolute_before_await():
+    body = _function_body(UI_JS, "submitEdit")
+    cap = re.search(r"absoluteKeepCount\s*=\s*_oldestIdx\s*\+\s*msgIdx", body)
+    assert cap
+    first_await = re.search(r"\bawait\b", body)
+    assert first_await and cap.start() < first_await.start()