This is a patch to fix the main issue in bug #54254,
cal_from_jd(CAL_JEWISH) returns month=6 for Adar when there is only
one Adar, (it should return 7, since if there is only one Adar it's
AdarII). This will clear up an issue where cal_from_jd() returns a
month that cal_days_in_month() reports to have 0 days due to an
inconsistency in how dates are converted to and from the Jewish
calendar. This patch should create the correct behavior.
I hope this can be applied and put into place soon, as this bug causes
malfunctions that have to be worked around.