Retry instead of error when Google response fails with MALFORMED_FUNCTION_CALL or other recoverable finish reason (#3300)

Author: ArneZsng

pydantic_ai_slim/pydantic_ai/models/google.py

@@ -471,11 +471,9 @@ def _process_response(self, response: GenerateContentResponse) -> ModelResponse:
                 raise UnexpectedModelBehavior(
                     f'Content filter {raw_finish_reason.value!r} triggered', response.model_dump_json()
                 )
-            else:
-                raise UnexpectedModelBehavior(
-                    'Content field missing from Gemini response', response.model_dump_json()
-                )  # pragma: no cover
-        parts = candidate.content.parts or []
+            parts = []  # pragma: no cover
+        else:
+            parts = candidate.content.parts or []
 
         usage = _metadata_as_usage(response)
         return _process_response_from_parts(
@@ -649,17 +647,12 @@ async def _get_event_iterator(self) -> AsyncIterator[ModelResponseStreamEvent]:
             #     )
 
             if candidate.content is None or candidate.content.parts is None:
-                if self.finish_reason == 'stop':  # pragma: no cover
-                    # Normal completion - skip this chunk
-                    continue
-                elif self.finish_reason == 'content_filter' and raw_finish_reason:  # pragma: no cover
+                if self.finish_reason == 'content_filter' and raw_finish_reason:  # pragma: no cover
                     raise UnexpectedModelBehavior(
                         f'Content filter {raw_finish_reason.value!r} triggered', chunk.model_dump_json()
                     )
                 else:  # pragma: no cover
-                    raise UnexpectedModelBehavior(
-                        'Content field missing from streaming Gemini response', chunk.model_dump_json()
-                    )
+                    continue
 
             parts = candidate.content.parts
             if not parts: