Refactor "extract method" false negative on local variables in 'for'

[Alberth289346]

This is the 2nd refactor bug in the same original code as #1291 after working around the first refusal.

Encountered in Eclipse 2023-03, and confirmed in 2024-03. It seems related to my previous bug report #671 except that was in while context.

I assumed the cause for both bugs are different, so I simplified the original code independent from what I did in #1291. That lead to

package completion2.grammar;

import java.util.ArrayList;
import java.util.List;

public class RefactorFalseNegativeLocalVars {

    public static void falseNegativeLocalVarsRefactor(List<String> defs) {
        List<String> newDefs = new ArrayList<>();

        for (String rule: defs) {
            boolean isLeftRecursive = false;
            if (!isLeftRecursive) {
                continue;
            }

            List<String> oldRules = new ArrayList<String>();
            List<String> newSuffixes = new ArrayList<String>();

            newDefs.addAll(oldRules);
            newDefs.addAll(newSuffixes);
        }
    }
}

When you try to extract the body of the loop to a new method, you get

This is a wrong conclusion since the local variables are local to the extracted method, and cease to exist at the end of that body. If the code performs continue, I would hope the local oldRules and newSuffixes variables are also created from scratch again, but even if they don't, they are initialized in the declaration after the continue, so any old data in them would be destroyed.