revlog: make pure version of _partialmatch() support 40-byte hex nodeids Without this patch, test-histedit-arguments.t would fail when run with --pure. It turned out to be because the pure version of _partialmatch() does not support full 40-byte hex nodeids. When histedit's instructions include things like "pick tip", it resolves the "tip" revision early to a full nodeid (but plain hex nodeid prefixes are not resolved to full nodeids). Then the nodeid (full or not) is looked up using to a full nodeid later. This step is what fails in pure mode. It has been failing since my c4131138eadb (histedit: look up partial nodeid as partial nodeid, 2018-04-06). I haven't verified, but I suspect histedit instructions like "pick <full hex nodeid>" would have been failing before my commit too, though. The fix is trivial: change a "< 40" to "<= 40". Differential Revision: https://phab.mercurial-scm.org/D3428

Set up

  $ hg init repo
  $ cd repo

Try to import an empty patch

  $ hg import --no-commit - <<EOF
  > EOF
  applying patch from stdin
  abort: stdin: no diffs found
  [255]

No dirstate backups are left behind

  $ ls .hg/dirstate* | sort
  .hg/dirstate