Ignoring the Return Values Of Immutable Objects [LUCENE-5506]

I was checking the source code of Lucene and I realized that return values of immutable objects are ignored at CSVUtil.java and Compile.java as follows:

**CSVUtil.java**:

```Java
/**
* Quote and escape input value for CSV
*/
public static String quoteEscape(String original) {
String result = original;

if (result.indexOf('\"') >= 0) {
result.replace("\"", ESCAPED_QUOTE);
}
if(result.indexOf(COMMA) >= 0) {
result = "\"" + result + "\"";
}
return result;
}
```

**Compile.java**

```Java
if (args.length < 1) {
return;
}

args[0].toUpperCase(Locale.ROOT);
```

---
Migrated from [LUCENE-5506](https://issues.apache.org/jira/browse/LUCENE-5506) by Furkan Kamaci, 1 vote, updated May 09 2016
Attachments: [LUCENE-5506.patch](https://apache.github.io/lucene-jira-archive/attachments/LUCENE-5506/LUCENE-5506.patch)
Linked issues:
- #6584
- #6913

Start by reading the quoteEscape method in CSVUtil.java and the argument handling around args[0] in Compile.java. Check the existing behavior for quoted CSV values and uppercased arguments; done means both methods use the intended transformed values without changing unrelated behavior.

Written by the indexing model from the issue text.