fix(bedrock): degrade gracefully on truncated tool-call arguments instead of failing the request

[arashne]

Withdrawing — we're handling this case on the client side instead. Thanks for the project.

[greptile-apps]

Greptile Summary

This PR fixes a deterministic request-poisoning bug where a Bedrock ConverseStream that ends mid-tool-call leaves a truncated JSON arguments string in the conversation history, causing every subsequent replay of that conversation to hard-fail with a JSONDecodeError. The fix makes split_concatenated_json_objects degrade gracefully — catching the decode error, emitting a verbose_logger.warning, and returning whatever complete objects were parsed — so the caller falls through to input={} rather than crashing.

• common_utils.py: Single try/except wrapping decoder.raw_decode; on failure logs parse position, error, and object count, then breaks. The existing empty-result fallback in _convert_to_bedrock_tool_call_invoke (the function's only caller) handles input={} with no other changes required.
• Tests: Old "invalid JSON raises" contract test correctly updated to the new degrade contract; four new tests cover the splitter (truncated-single, salvage-prefix) and the Bedrock converter (exact production truncation shape, salvage before truncated tail).

Confidence Score: 5/5

Safe to merge — the change is a minimal, targeted catch-and-log in a single function with one production caller, and the existing fallback in that caller already handles the empty-result case correctly.

The fix is a three-line try/except replacing a bare raw_decode call. The pre-existing if parsed_objects: / arguments_dict = {} fallback in _convert_to_bedrock_tool_call_invoke (the sole production caller) is unmodified and correctly handles the empty-list result. The updated test contract change is intentional and correct — the old 'raises' assertion described the broken behavior, not a regression guard. New tests cover the exact production truncation shape, partial salvage, and end-to-end Bedrock conversion, providing solid regression coverage for the fixed path.

No files require special attention.

Important Files Changed

Filename	Overview
litellm/litellm_core_utils/prompt_templates/common_utils.py	Wraps the inner decoder.raw_decode call in a try/except; on JSONDecodeError logs a warning and breaks instead of propagating. Minimal, targeted fix with clear logging.
tests/test_litellm/litellm_core_utils/prompt_templates/test_litellm_core_utils_prompt_templates_common_utils.py	Old "invalid JSON raises" test renamed and corrected to match the new degrade contract; two new splitter tests cover truncated-single-object and partial-salvage cases.
tests/test_litellm/litellm_core_utils/prompt_templates/test_litellm_core_utils_prompt_templates_factory.py	Two new end-to-end tests for _convert_to_bedrock_tool_call_invoke: exact production-truncation shape degrades to input={}, and salvage of a complete object before a truncated tail.

_{Reviews (2): Last reviewed commit: "log a warning when an unparseable tool-c..." | Re-trigger Greptile}

[codecov]

Codecov Report

✅ All modified and coverable lines are covered by tests.

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[codspeed-hq]

Merging this PR will not alter performance

✅ 31 untouched benchmarks

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_{Comparing arashne:fix/bedrock-truncated-tool-args-degrade (f3cff16) with litellm_internal_staging (bf02a4a)}

[arashne]

@greptileai