Dmitry Tantsur 00ad03b709 Fixes minor issues in the read() retries patch
Follow-up to commit c5b97eb781cf9851f9abe87a1500b4da55b8bde8.

Two things slipped through the cracks:
* ImageDownloadError was instantiated incorrectly, resulting in a wrong
  error message. This was uncovered by using assertRaisesRegext in tests.
* We allowed calling write(None). This was uncovered by avoiding sleep(4)
  in tests and enabling more failed calls before timeout.

Change-Id: If5e798c5461ea3e474a153574b0db2da96f2dfa8
2020-06-30 10:51:53 +02:00
..
2020-03-12 10:35:17 -07:00
2020-03-12 10:35:17 -07:00