tests/test-import-context.t

pull: avoid race condition with 'hg pull --rev name --update' (issue4706)

The previous scheme was:

1) lookup node for all pulled revision,
2) pull said node
3) lookup the node of the checkout target
4) update the repository there.

If the remote repo changes between (1) and (3), the resolved name will be
different and (3) crash. There is actually no need for a remote lookup during
(3), we could just set the value in (1). This prevent the race condition and
save a possible network roundtrip.

Test applying context diffs

  $ cat > writepatterns.py <<EOF
  > import sys
  > 
  > path = sys.argv[1]
  > lasteol = sys.argv[2] == '1'
  > patterns = sys.argv[3:]
  > 
  > fp = file(path, 'wb')
  > for i, pattern in enumerate(patterns):
  >     count = int(pattern[0:-1])
  >     char = pattern[-1] + '\n'
  >     if not lasteol and i == len(patterns) - 1:
  >         fp.write((char*count)[:-1])
  >     else:
  >         fp.write(char*count)
  > fp.close()
  > EOF
  $ cat > cat.py <<EOF
  > import sys
  > sys.stdout.write(repr(file(sys.argv[1], 'rb').read()) + '\n')
  > EOF

Initialize the test repository

  $ hg init repo
  $ cd repo
  $ python ../writepatterns.py a 0 5A 1B 5C 1D
  $ python ../writepatterns.py b 1 1A 1B
  $ python ../writepatterns.py c 1 5A
  $ python ../writepatterns.py d 1 5A 1B
  $ hg add
  adding a
  adding b
  adding c
  adding d
  $ hg ci -m addfiles

Add file, missing a last end of line

  $ hg import --no-commit - <<EOF
  > *** /dev/null	2010-10-16 18:05:49.000000000 +0200
  > --- b/newnoeol	2010-10-16 18:23:26.000000000 +0200
  > ***************
  > *** 0 ****
  > --- 1,2 ----
  > + a
  > + b
  > \ No newline at end of file
  > *** a/a	Sat Oct 16 16:35:51 2010
  > --- b/a	Sat Oct 16 16:35:51 2010
  > ***************
  > *** 3,12 ****
  >   A
  >   A
  >   A
  > ! B
  >   C
  >   C
  >   C
  >   C
  >   C
  > ! D
  > \ No newline at end of file
  > --- 3,13 ----
  >   A
  >   A
  >   A
  > ! E
  >   C
  >   C
  >   C
  >   C
  >   C
  > ! F
  > ! F
  > 
  > *** a/b	2010-10-16 18:40:38.000000000 +0200
  > --- /dev/null	2010-10-16 18:05:49.000000000 +0200
  > ***************
  > *** 1,2 ****
  > - A
  > - B
  > --- 0 ----
  > *** a/c	Sat Oct 16 21:34:26 2010
  > --- b/c	Sat Oct 16 21:34:27 2010
  > ***************
  > *** 3,5 ****
  > --- 3,7 ----
  >   A
  >   A
  >   A
  > + B
  > + B
  > *** a/d	Sat Oct 16 21:47:20 2010
  > --- b/d	Sat Oct 16 21:47:22 2010
  > ***************
  > *** 2,6 ****
  >   A
  >   A
  >   A
  > - A
  > - B
  > --- 2,4 ----
  > EOF
  applying patch from stdin
  $ hg st
  M a
  M c
  M d
  A newnoeol
  R b

What's in a

  $ python ../cat.py a
  'A\nA\nA\nA\nA\nE\nC\nC\nC\nC\nC\nF\nF\n'
  $ python ../cat.py newnoeol
  'a\nb'
  $ python ../cat.py c
  'A\nA\nA\nA\nA\nB\nB\n'
  $ python ../cat.py d
  'A\nA\nA\nA\n'

  $ cd ..