[java] UseEqualsToCompareStrings should consider return type

[ghost]

Affects PMD Version:6.42.0

Rule:UseEqualsToCompareStrings

Please provide the rule name and a link to the rule documentation:
https://pmd.github.io/latest/pmd_rules_java_errorprone.html#useequalstocomparestrings

Description:
Hi, I found a false negative about the rule UseEqualsToCompareStrings. Please review the following code example. PMD should have reported a warning at line 5 because the string x is compared with another string, but it doesn't. Hence, I think it is a false negative.

Code Sample demonstrating the issue:

String getLiteral() {
  return "hello";
}
void UseEqualsToCompareStrings(String x) {
  if (x == getLiteral()) {} // a false negative should report
}

Expected outcome:

PMD should report a violation at line 5, but doesn't. This is a false-negative.

Running PMD through: [Maven]

[jsotuyod]

This is fixed in PMD 7.0.0-rc1. It won't be backported to PMD 6.