orabig / apache-magic-trick

This is a very weird bug of Apache in a form of "magic trick"

How to reproduce an unexplained bug in Apache 2.4.10 (Jessie) and turn it into a magic trick

$ docker build . -t apache2:2.4.10
$ watch 'docker run --rm -v $(pwd)/buggy.conf:/etc/apache2/sites-enabled/buggy.conf apache2:2.4.10 apache2ctl -V'

This shows an apache error (refreshed in real-time), looking like :

AH00526: Syntax error on line 6 of /etc/apache2/sites-enabled/buggy.conf:
Invalid command '}"', perhaps misspelled or defined by a module not included in the server configuration
Action '-V' failed.
The Apache error log may have more information.

Magic trick

Edit buggy.conffile : Add or remove ANY character inside the LogFormat definition and Puff : no more error !!!

(For information : this configuration file should work : LogFormat may contain any string, and { ... } is not supposed to be interpreted : https://httpd.apache.org/docs/current/fr/mod/mod_log_config.html )

Side note

I know that this bug does not exist in Apache:2.4.25 (which is used in stretch), thus there should be a specific fix between these versions. If anyone could point it out to me, I'd be very glad (and ready to offer a beer)