Support the suppress_if_match option from old svn-mailer
suppress_if_match is/was used to suppress emails if a later mailer section also matches the current svn event, thus allowing the first section(s) to act as a fallback if no other, more specific section matches.
This brings back that functionality, avoiding duplicate emails for configurations that make use of suppress_if_match
Just curious. What is the "old svn-mailer"? I can't find this option in mailer.py (I tried to bisect the history up to gstein's work 2023/2024) but couldn't find it. Is it some ASF/Infra-local version?
See https://issues.apache.org/jira/browse/INFRA-27061, there is a link to the version I used to generate the patch.
The original work, I believe, is https://opensource.perlig.de/svnmailer/ which also explains how suppress_if_match works