False positive of Style/IdenticalConditionalBranches when conditional mutates duplicate line

[martinemde]

Expected behavior

When the conditional mutates the variable used in the duplication, the conditional should not be considered a violation of cop Style/IdenticalConditionalBranches.

Actual behavior

This is identified as a duplicate branch, but because the duplicated line's behavior is modified by the conditional, it should not be caught by the cop, similar to #9982 where the conditional checks x == 0 before x += 1.

Steps to reproduce the problem

Extracted from Bundler, this removes a leading - and performs a different action depending on if the - existed.

if version.delete_prefix!("-")
  version = version.split("-", 2).unshift(name)
  versions_by_name[name].delete(version)
else
  version = version.split("-", 2).unshift(name)
  versions_by_name[name] << version
end

The unsafe auto-correct is as follows, which is wrong:

version = version.split("-", 2).unshift(name)
if version.delete_prefix!("-")
  versions_by_name[name].delete(version)
else
  versions_by_name[name] << version
end

The version I ended up with that avoids this issue is in this PR.

RuboCop version

1.56.3