Regexp: violation pointing to line 0 while other Checks count first line as 1

[romani]

https://checkstyle.org/checks/regexp/regexp.html#Regexp

problem is detected at #14057 and blocks it as test suite can not accept line 0 as expected.

$ cat config.xml 
<?xml version="1.0"?>
<!DOCTYPE module PUBLIC
          "-//Puppy Crawl//DTD Check Configuration 1.3//EN"
          "http://www.puppycrawl.com/dtds/configuration_1_3.dtd">

<module name="Checker">
  <module name="TreeWalker">
    <module name="Regexp">
      <property name="format" value="// This code is copyrighted"/>
    </module>
  </module>
</module>

$ cat Test.java 
// comment
public class TestClass {
}

$ java -jar checkstyle-10.12.4-all.jar -c config.xml Test.java
Starting audit...
[ERROR] /var/tmp/Test.java:0: Required pattern '// This code is copyrighted' missing in file. [Regexp]
Audit done.
Checkstyle ends with 1 errors.

example for other Check that shows that line number is 1

$ cat config.xml 
<?xml version="1.0"?>
<!DOCTYPE module PUBLIC
          "-//Puppy Crawl//DTD Check Configuration 1.3//EN"
          "http://www.puppycrawl.com/dtds/configuration_1_3.dtd">

<module name="Checker">
      <module name="FileLength">
        <property name="max" value="1"/>
      </module>
</module>

$ cat Test.java 
// comment
public class TestClass {
}

$ java -jar checkstyle-10.12.4-all.jar -c config.xml Test.java
Starting audit...
[ERROR] /var/tmp/Test.java:1: File length is 3 lines (max allowed is 1). [FileLength]
Audit done.
Checkstyle ends with 1 errors.

prove in code that line length starts from 1:

checkstyle/src/main/java/com/puppycrawl/tools/checkstyle/api/FileText.java

Lines 279 to 280 in 5509746

	// now we have lineNo and columnNo, both starting at zero.
	return new LineColumn(lineNo + 1, columnNo);

Expected:
[ERROR] /var/tmp/Test.java:1: Required pattern '// This code is copyrighted' missing in file. [Regexp]

[romani]

I think it should be "bug" and we consider "breaking compatibility" for config in most cases, this is change in behavior.