Yes, I'm currently testing the change with a bunch of OpenSSL and LibreSSL versions.

By the way the memory issue can be reproduced with any certificate that contains a CRL distribution point. Letsencrypt certs don't have a CRL DP. I guess Alexander's test cert doesn't have a CRL DP either. The Nokia test cert in our test suite contains one.

---
import _ssl
import sys

PEM = 'Lib/test/nokia.pem'

def mem():
    with open('/proc/self/status') as f:
        for line in f:
            if line.startswith('RssAnon'):
                print(line, end='')

for i in range(10000):
    if i % 1000 == 0:
        mem()
    d = _ssl._test_decode_cert(PEM)
    assert d['crlDistributionPoints']

mem()
---

Without fix:

$ ./python t.py 
RssAnon:            4376 kB
RssAnon:            4840 kB
RssAnon:            5224 kB
RssAnon:            5608 kB
RssAnon:            6120 kB
RssAnon:            6504 kB
RssAnon:            6888 kB
RssAnon:            7272 kB
RssAnon:            7656 kB
RssAnon:            8040 kB
RssAnon:            8424 kB


With fix:

$ ./python t.py 
RssAnon:            4376 kB
RssAnon:            4376 kB
RssAnon:            4376 kB
RssAnon:            4376 kB
RssAnon:            4376 kB
RssAnon:            4376 kB
RssAnon:            4376 kB
RssAnon:            4376 kB
RssAnon:            4376 kB
RssAnon:            4376 kB
RssAnon:            4376 kB