Quote value starting with comment marker in minimal quote mode

[rootvector2]

printWithQuotes (the default MINIMAL quote mode) decides whether to encapsulate a value by special-casing only the hard-coded # (Constants.COMMENT) as the first character, so a configured comment marker greater than # such as ; is left unquoted. I hit this round-tripping printer output back through the parser: CSVFormat.DEFAULT.builder().setCommentMarker(';').get() prints ";id", "name" as ;id,name, and re-parsing with that same format reads the line as a comment and silently drops the whole record.

The encapsulation check is the right place to fix it, since that is already where the printer protects the default comment char, the delimiter, the quote and newlines. The change quotes a value whenever its first character equals the configured comment marker, so the output reads back as data.

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[garydgregory]

Hello @rootvector2

Thank you for the PR.

Would you please update the new test to make sure that comments are properly printed. We want to make sure the new test shows the difference between printing a comment and printing a value that happens to start with the comment char.

Can you think of other cases to test?

[rootvector2]

Done. The test now prints a real comment with printComment first, then the leading-marker value, so the output makes the difference explicit: ; a real comment stays a comment line while ;comment-like becomes ";comment-like".

Added a couple more cases too: the marker past the first character (a;b) is left unquoted since it can't start a comment, and a leading marker in a non-first column (;c) is still quoted. The round-trip check confirms the comment is dropped on read and both data records survive.

[garydgregory]

@rootvector2
Please don't bother pushing to github until you've run mvn by itself to run and fix all build failures 🦺

[rootvector2]

My fault. It was checkstyle OperatorWrap on the multi-line assertEquals concatenation, the + has to sit at the end of the line, not the start of the next. Fixed it and re-ran mvn by itself, build's green now with 0 violations. Amended into the test commit.