[fixfon]

Summary

Part of #29422.

SIM102 missed a nested if inside an elif whenever the first branch had more than one statement. In nested_if_body, when the last branch is an elif we pick that clause as the nested if, but the "only one statement" check still looked at the outer if body. So the length check was done on the wrong body.

The fix checks nested_if.body().len() instead, so an elif uses its own body. The plain if path behaves the same as before.

This only covers the SIM102 item from the issue. I didn't touch the other rules there.

Test Plan

I added two cases to SIM102.py: an elif that only contains a nested if after a multi-statement first branch (now flagged), and one where the elif has another statement next to the nested if (still not flagged). The example from the issue is now reported at 5:5. The snapshot also gets one extra context line on the previous last diagnostic, because the file doesn't end there anymore.

cargo test -p ruff_linter and clippy both pass.

I used Claude (via T3 Code) to help with this change, and I reviewed and tested it myself.

[ntBre]

Thank you