view tests/test-mq-symlinks.t @ 49269:395f28064826

worker: avoid potential partial write of pickled data

Previously, the code wrote the pickled data using os.write(). However,
os.write() can write less bytes than passed to it. To trigger the problem, the
pickled data had to be larger than 2147479552 bytes on my system.

Instead, open a file object and pass it to pickle.dump(). This also has the
advantage that it doesn’t buffer the whole pickled data in memory.

Note that the opened file must be buffered because pickle doesn’t support
unbuffered streams because unbuffered streams’ write() method might write less
bytes than passed to it (like os.write()) but pickle.dump() relies on that all
bytes are written (see https://github.com/python/cpython/issues/93050).

The side effect of using a file object and a with statement is that wfd is
explicitly closed now while it seems like before it was implicitly closed by
process exit.

#require symlink

  $ echo "[extensions]" >> $HGRCPATH
  $ echo "mq=" >> $HGRCPATH

  $ hg init
  $ hg qinit
  $ hg qnew base.patch
  $ echo aaa > a
  $ echo bbb > b
  $ echo ccc > c
  $ hg add a b c
  $ hg qrefresh
  $ readlink.py a
  a -> a not a symlink


test replacing a file with a symlink

  $ hg qnew symlink.patch
  $ rm a
  $ ln -s b a
  $ hg qrefresh --git
  $ readlink.py a
  a -> b

  $ hg qpop
  popping symlink.patch
  now at: base.patch
  $ hg qpush
  applying symlink.patch
  now at: symlink.patch
  $ readlink.py a
  a -> b


test updating a symlink

  $ rm a
  $ ln -s c a
  $ hg qnew --git -f updatelink
  $ readlink.py a
  a -> c
  $ hg qpop
  popping updatelink
  now at: symlink.patch
  $ hg qpush --debug
  applying updatelink
  patching file a
  committing files:
  a
  committing manifest
  committing changelog
  updating the branch cache
  now at: updatelink
  $ readlink.py a
  a -> c
  $ hg st


test replacing a symlink with a file

  $ ln -s c s
  $ hg add s
  $ hg qnew --git -f addlink
  $ rm s
  $ echo sss > s
  $ hg qnew --git -f replacelinkwithfile
  $ hg qpop
  popping replacelinkwithfile
  now at: addlink
  $ hg qpush
  applying replacelinkwithfile
  now at: replacelinkwithfile
  $ cat s
  sss
  $ hg st


test symlink removal

  $ hg qnew removesl.patch
  $ hg rm a
  $ hg qrefresh --git
  $ hg qpop
  popping removesl.patch
  now at: replacelinkwithfile
  $ hg qpush
  applying removesl.patch
  now at: removesl.patch
  $ hg st -c
  C b
  C c
  C s

replace broken symlink with another broken symlink

  $ ln -s linka linka
  $ hg add linka
  $ hg qnew link
  $ hg mv linka linkb
  $ rm linkb
  $ ln -s linkb linkb
  $ hg qnew movelink
  $ hg qpop
  popping movelink
  now at: link
  $ hg qpush
  applying movelink
  now at: movelink
  $ readlink.py linkb
  linkb -> linkb