[KVR Vishnu (VISHNU0906)]

Motivation and Context

A process step that has both add(a, b) and a no-input reset() raises ProcessTargetFunctionNameMismatchException when a message fills only part of add. The same wiring without reset() waits correctly. Caught in #14729 by PRABHU KIRAN VANDRANKI (@VANDRANKI) (thanks again for the repro and the clear root-cause write-up).

Fixes #14729

Description

In LocalStep.handle_message and the matching StepActor.handle_message, only inspect the function the message targets. If that function still has missing inputs, log and wait. A sibling that needs no input (or only step context) is always ready and must not count as "became invocable because of this message."

Adds local-step coverage for no-input and step-context-only siblings, a control that still runs a no-input function when it is the target, a Dapr step-actor case, and an end-to-end ProcessBuilder fan-in with a relay (the issue shape).

Contribution Checklist

• The code builds clean without any errors or warnings
• The PR follows the SK Contribution Guidelines and the pre-submission formatting script raises no violations
• All unit tests pass, and I have added new tests where possible
• I didn't break anyone 😄

[Copilot]

🟢 Approval recommended

No active review issues are recorded for the target-specific function readiness change.

No open issues 🎉

What changed in this PR

Fixes #14729 by making Python process steps check readiness only for the function targeted by a message. This lets partial inputs wait for completion without a no-input sibling causing a function-name mismatch.

Changes:

• Apply target-specific readiness checks in both local and Dapr runtimes.
• Add regression coverage for no-input and context-only siblings, plus direct invocation of a no-input function.
• Add an end-to-end relay fan-in test matching the reported issue.

File	Description
python/​tests/​unit/​processes/​local_runtime/​test_local_step.py	Tests partial-input waiting and targeted no-input invocation.
python/​tests/​unit/​processes/​local_runtime/​test_local_process.py	Adds an end-to-end relay fan-in regression test.
python/​tests/​unit/​processes/​dapr_runtime/​test_step_actor.py	Tests partial-input waiting in the Dapr actor.
python/​semantic_kernel/​processes/​local_runtime/​local_step.py	Checks only the targeted function’s missing inputs.
python/​semantic_kernel/​processes/​dapr_runtime/​actors/​step_actor.py	Applies the same readiness logic to Dapr steps.

_{Review effort: Balanced}