Root cause for SOLR-4867. Trying to set the root logging category results in the addition of a category that's the empty string.
Admin UI - setting loglevel on root throws RangeError
Patch to fix the issue. Shalin Shekhar Mangar, the CHANGES.txt entry is under 4.3.1, so I'd like to know whether it's OK to backport. If not, I'll move that to 4.4.
Something related, not sure whether it's worth fixing: If you change the logging level to WARN (or below) on something low level like org (or the root, after this patch), you don't get anything in the log about changing the level - because the log entry about the change is INFO.
+1 - patch looks clean and correct to me.
As discussed with shawn on IRC, JulWatcher has similar code, but that seems to be correct - most likely this bug stemmed from the JulWatcher code being copied/modified to create the Log4jWatcher
Shawn Heisey – Go ahead and backport it.
Bulk close after 4.3.1 release