Fix the first linebreak of messages that aborts printing #1455

[Danielmelody]

Description

To handle something like this

TEST_CASE( "INFO and WARN start with a linebreak", "[messages][.]" ) {
    INFO( "\nthis is a " << "message start with a linebreak" );
    WARN( "\nthis is a " << "warning start with a linebreak" );
}

GitHub Issues

#1455

[codecov]

Codecov Report

Merging #1470 into master will decrease coverage by 0.03%.
The diff coverage is n/a.

@@            Coverage Diff             @@
##           master    #1470      +/-   ##
==========================================
- Coverage   80.38%   80.35%   -0.03%     
==========================================
  Files         121      121              
  Lines        3425     3425              
==========================================
- Hits         2753     2752       -1     
- Misses        672      673       +1

[codecov]

Codecov Report

Merging #1470 into master will decrease coverage by 0.03%.
The diff coverage is n/a.

@@            Coverage Diff             @@
##           master    #1470      +/-   ##
==========================================
- Coverage   80.38%   80.35%   -0.03%     
==========================================
  Files         121      121              
  Lines        3425     3425              
==========================================
- Hits         2753     2752       -1     
- Misses        672      673       +1

[horenmar]

Thanks for the PR, but the fix should go through the TextFlow repository (as the error is in a code that is 3rd party to Catch).
@philsquared

[Danielmelody]

All right I see that, but that's quite confusing, I didn't even notice there are 3rd party codes in catch2 until you remind me.