recover concatenated artifact writes

src/clean_agent_preview.py

@@ -624,11 +624,22 @@ def explicit_text_artifact_target(user_text):
 def malformed_write_handoff_target(arguments, required_artifacts=(), user_text=''):
     """Recover one textual write target even when no prompt path was parsed."""
     candidates = tuple(required_artifacts or ())
-    target = candidates[0] if len(candidates) == 1 else (
-        _partial_json_string_field(arguments, 'path')
-        or explicit_text_artifact_target(user_text)
+    recovered = _partial_json_string_field(arguments, 'path')
+    sole_required = str(candidates[0] or '').strip() if len(candidates) == 1 else ''
+    # A runner may require a directory containing several outputs.  It is not
+    # itself a writable file target, so prefer the concrete descendant path in
+    # the malformed call.  Exact required files remain authoritative.
+    target = (
+        sole_required
+        if sole_required and Path(sole_required).suffix
+        else recovered or explicit_text_artifact_target(user_text)
     )
     target = str(target or '').strip()
+    if sole_required and not Path(sole_required).suffix:
+        required_root = os.path.normpath(sole_required)
+        normalized_target = os.path.normpath(target) if target else ''
+        if not normalized_target.startswith(required_root + os.sep):
+            return ''
     if not target or Path(target).suffix.lower() in _NON_TEXT_ARTIFACT_SUFFIXES:
         return ''
     return target
@@ -1637,6 +1648,72 @@ def protocol_safe_tool_calls(calls):
     return safe_calls
 
 
+def expand_concatenated_write_calls(calls, *, max_calls=16):
+    """Split one unambiguous stream of write_file JSON objects.
+
+    Some OpenAI-compatible providers serialize a requested multi-call batch as
+    adjacent JSON objects inside one ``arguments`` string.  Recover only the
+    narrow write-file shape; all expanded calls still pass the ordinary schema,
+    policy, workspace, repeat, and execution checks later in the loop.
+    """
+    expanded = []
+    recovered_count = 0
+    decoder = json.JSONDecoder()
+    for call in calls or ():
+        function = call.get('function') or {}
+        raw = function.get('arguments') or ''
+        if canonical(function.get('name', '')) != 'write_file':
+            expanded.append(call)
+            continue
+        try:
+            json.loads(raw)
+        except (TypeError, ValueError, json.JSONDecodeError):
+            pass
+        else:
+            expanded.append(call)
+            continue
+        if not isinstance(raw, str):
+            expanded.append(call)
+            continue
+        items = []
+        cursor = 0
+        try:
+            while cursor < len(raw):
+                while cursor < len(raw) and raw[cursor].isspace():
+                    cursor += 1
+                if cursor >= len(raw):
+                    break
+                item, cursor = decoder.raw_decode(raw, cursor)
+                items.append(item)
+                if len(items) > max_calls:
+                    raise ValueError('too many concatenated write calls')
+        except (TypeError, ValueError, json.JSONDecodeError):
+            expanded.append(call)
+            continue
+        if not (2 <= len(items) <= max_calls) or not all(
+            isinstance(item, dict)
+            and set(item) == {'path', 'content'}
+            and isinstance(item['path'], str)
+            and bool(item['path'].strip())
+            and isinstance(item['content'], str)
+            for item in items
+        ):
+            expanded.append(call)
+            continue
+        base_id = str(call.get('id') or 'call_write')
+        for index, item in enumerate(items):
+            expanded.append({
+                'id': f'{base_id}_{index}',
+                'type': 'function',
+                'function': {
+                    'name': function.get('name', 'write_file'),
+                    'arguments': json.dumps(item, ensure_ascii=False),
+                },
+            })
+        recovered_count += len(items)
+    return expanded, recovered_count
+
+
 def artifact_body_from_handoff(response):
     """Extract a complete textual artifact body from a no-tools recovery turn."""
     raw = str(response or '').strip()
@@ -4746,6 +4823,14 @@ async def stream_preview(*, endpoint_url, model, messages, headers, turn_contrac
                             })
                         else:
                             unexecutable_dsml_completion = True
+                proposed, recovered_write_calls = expand_concatenated_write_calls(proposed)
+                if recovered_write_calls:
+                    yield event({
+                        'type': 'tool_argument_recovery',
+                        'format': 'concatenated_json_objects',
+                        'round': round_number,
+                        'calls': recovered_write_calls,
+                    })
                 proposed = serialize_required_email_attachment_chain(
                     proposed, contract_required_tools, executions,
                 )