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Evan Mattson
08feb2aebf
### Motivation and Context
The existing implementation of `kernel.invoke_function_call(...)` stores
mutable tool return values by reference. Subsequent mutations to the
same in-memory state bleed into earlier chat messages, which corrupts
conversation history and breaks reproducibility. By deep-copying the
function result immediately after execution, we can guarantee an
immutable snapshot of each tool's output at the time of invocation,
which preserves previous tool invocations and removes unwanted side
effects.
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### Description
After `await stack(invocation_context)` in
`kernel.invoke_function_call(...)`, we now have:
```python
if invocation_context.function_result and invocation_context.function_result.value is not None:
invocation_context.function_result.value = copy.deepcopy(
invocation_context.function_result.value
)
```
This has no change to our public API or user-facing behavior; internal
state handling is now robust against undesired mutations.
- Adds a unit test to exercise the new behavior and assert on the proper
mutations/states.
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### Contribution Checklist
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- [X] The code builds clean without any errors or warnings
- [X] The PR follows the [SK Contribution
Guidelines](https://github.com/microsoft/semantic-kernel/blob/main/CONTRIBUTING.md)
and the [pre-submission formatting
script](https://github.com/microsoft/semantic-kernel/blob/main/CONTRIBUTING.md#development-scripts)
raises no violations
- [X] All unit tests pass, and I have added new tests where possible
- [X] I didn't break anyone 😄