Rules validation throws exception instead or warning

[skyper]

What steps will reproduce the problem? ¶

1. (Re-)Load a broken rule file containing backslashes '\' in the assertMatch values can cause this exception.

What is the expected result? ¶

Message including the line and the position of the problem but no BugReportHandler

What happens instead? ¶

BugReportHandler

Please provide any additional information below. Attach a screenshot if possible. ¶

After that, JOSM stops to automatically reload the rule file.
Do not get the BugReportHandler all the time but the exception on the console.

Relative:URL: ^/trunk
Repository:UUID: 0c6e7542-c601-0410-84e7-c038aed88b3b
Last:Changed Date: 2020-07-06 23:02:10 +0200 (Mon, 06 Jul 2020)
Revision:16738
Build-Date:2020-07-07 01:30:48
URL:https://josm.openstreetmap.de/svn/trunk

Plugins:
+ tagging-preset-tester (35267)

Validator rules:
+ ${HOME}/JOSM/validator/GTFS_rules.mapcss

Last errors/warnings:
- E: Handled by bug report queue: java.lang.IllegalArgumentException: Expecting n/node/w/way/r/relation/area, but got '"node'


=== REPORTED CRASH DATA ===
BugReportExceptionHandler#handleException:
No data collected.

Warning issued by: BugReportExceptionHandler#handleException

=== STACK TRACE ===
Thread: File Watcher (23)
java.lang.IllegalArgumentException: Expecting n/node/w/way/r/relation/area, but got '"node'
	at org.openstreetmap.josm.data.osm.OsmUtils.createPrimitive(OsmUtils.java:171)
	at org.openstreetmap.josm.data.validation.tests.MapCSSTagCheckerAsserts.checkAsserts(MapCSSTagCheckerAsserts.java:60)
	at org.openstreetmap.josm.data.validation.tests.MapCSSTagChecker$TagCheck.ofMapCSSRule(MapCSSTagChecker.java:344)
	at org.openstreetmap.josm.data.validation.tests.MapCSSTagChecker$TagCheck.readMapCSS(MapCSSTagChecker.java:366)
	at org.openstreetmap.josm.data.validation.tests.MapCSSTagChecker.addMapCSS(MapCSSTagChecker.java:790)
	at org.openstreetmap.josm.data.validation.tests.MapCSSTagChecker.addMapCSS(MapCSSTagChecker.java:778)
	at org.openstreetmap.josm.data.validation.tests.MapCSSTagChecker.reloadRule(MapCSSTagChecker.java:858)
	at org.openstreetmap.josm.io.FileWatcher.processEvents(FileWatcher.java:160)
	at java.base/java.lang.Thread.run(Thread.java:834)

[skyper]

Oh. an odd number of " in the assertMatch triggers this, too.

[skyper]

See #19685 for another exception raised by validating an incorrect rule.