[Checkins] [zopefoundation/ZODB] b8d7a8: Backport from 4.0 and later (#162)

[GitHub]

  Branch: refs/heads/3.10
  Home:   https://github.com/zopefoundation/ZODB
  Commit: b8d7a8567152d3827d886c9a23eff9190fce4c1e
      https://github.com/zopefoundation/ZODB/commit/b8d7a8567152d3827d886c9a23eff9190fce4c1e
  Author: Godefroid Chapelle <gotcha at bubblenet.be>
  Date:   2017-04-19 (Wed, 19 Apr 2017)

  Changed paths:
    M src/ZODB/blob.py

  Log Message:
  -----------
  Backport from 4.0 and later (#162)