Hello Logback team,

I encountered a unexpected behavior when trying to print out the log context name in the html output.

I configured a FileAppender with the following layout:

<layout class="ch.qos.logback.classic.html.HTMLLayout">
<Pattern>%d

%mdc

%contextName%msg</Pattern>
</layout>

With this pattern, non of the log messages end up in the file. The output completely stops after the table header.
If I remove "%contextName" from the pattern, I get my log messages written to the file as expected.

Could you please have a look at this issue.
Thank you in advance for your help.

Kind regards,
Rick