Run this command across the source:
perl -pi.bak -e 's/(20[012][0-9])-20[12][012]/$1-2023/g' `git ls-files`
and remove changes to po{,-docs}/*.po{,t} (these will be regenerated
later when we run 'make dist').
In case there are no event handlers registered with the handle,
get_all_event_callbacks will count 0 elements, trying to malloc a buffer
of that size. POSIX says that this can result in either a null pointer,
or an unusable pointer.
Short-circuit get_all_event_callbacks to allocate nothing when there are
no events, making sure to use its results only when there were events.
Run the following command over the source:
perl -pi.bak -e 's/(20[01][0-9])-2016/$1-2017/g' `git ls-files`
(Thanks Rich for the perl snippet, as used in past years.)