view tests/test-wireproto.t @ 14007:d764463b433e

atomictempfile: avoid infinite recursion in __del__().

The problem is that a programmer using atomictempfile directly can
make an innocent everyday mistake -- not enough args to the
constructor -- which escalates badly.  You would expect a simple
TypeError crash in that case, but you actually get an infinite
recursion that is surprisingly difficult to kill: it happens between
__del__() and __getattr__(), and Python does not handle infinite
recursion from __del__() well.

The fix is to not implement __getattr__(), but instead assign instance
attributes for the methods we wish to delegate to the builtin file
type: write() and fileno(). I've audited mercurial.* and hgext.* and
found no users of atomictempfile using methods other than write() and
rename(). I audited third-party extensions and found one (snap)
passing an atomictempfile to util.fstat(), so I also threw in
fileno().

The last time I submitted a similar patch, Matt proposed that we make
atomictempfile a subclass of file instead of wrapping it. Rejected on
grounds of unnecessary complexity: for one thing, it would make the
Windows implementation of posixfile quite a bit more complex. It would
have to become a subclass of file rather than a simple function -- but
since it's written in C, this is non-obvious and non-trivial.
Furthermore, there's nothing wrong with wrapping objects and
delegating methods: it's a well-established pattern that works just
fine in many cases. Subclassing is not the answer to all of life's
problems.

Test wire protocol argument passing

Setup repo:

  $ hg init repo

Local:

  $ hg debugwireargs repo eins zwei --three drei --four vier
  eins zwei drei vier
  $ hg debugwireargs repo eins zwei --four vier
  eins zwei None vier
  $ hg debugwireargs repo eins zwei
  eins zwei None None

HTTP:

  $ hg serve -R repo -p $HGPORT -d --pid-file=hg1.pid -E error.log -A access.log
  $ cat hg1.pid >> $DAEMON_PIDS

  $ hg debugwireargs http://localhost:$HGPORT/ un deux trois quatre
  un deux trois quatre
  $ hg debugwireargs http://localhost:$HGPORT/ eins zwei --four vier
  eins zwei None vier
  $ hg debugwireargs http://localhost:$HGPORT/ eins zwei
  eins zwei None None
  $ cat access.log
  * - - [*] "GET /?cmd=capabilities HTTP/1.1" 200 - (glob)
  * - - [*] "GET /?cmd=debugwireargs&four=quatre&one=un&three=trois&two=deux HTTP/1.1" 200 - (glob)
  * - - [*] "GET /?cmd=debugwireargs&four=quatre&one=un&three=trois&two=deux HTTP/1.1" 200 - (glob)
  * - - [*] "GET /?cmd=capabilities HTTP/1.1" 200 - (glob)
  * - - [*] "GET /?cmd=debugwireargs&four=vier&one=eins&two=zwei HTTP/1.1" 200 - (glob)
  * - - [*] "GET /?cmd=debugwireargs&four=vier&one=eins&two=zwei HTTP/1.1" 200 - (glob)
  * - - [*] "GET /?cmd=capabilities HTTP/1.1" 200 - (glob)
  * - - [*] "GET /?cmd=debugwireargs&one=eins&two=zwei HTTP/1.1" 200 - (glob)
  * - - [*] "GET /?cmd=debugwireargs&one=eins&two=zwei HTTP/1.1" 200 - (glob)

SSH (try to exercise the ssh functionality with a dummy script):

  $ cat <<EOF > dummyssh
  > import sys
  > import os
  > os.chdir(os.path.dirname(sys.argv[0]))
  > if sys.argv[1] != "user@dummy":
  >     sys.exit(-1)
  > if not os.path.exists("dummyssh"):
  >     sys.exit(-1)
  > os.environ["SSH_CLIENT"] = "127.0.0.1 1 2"
  > r = os.system(sys.argv[2])
  > sys.exit(bool(r))
  > EOF

  $ hg debugwireargs --ssh "python ./dummyssh" ssh://user@dummy/repo uno due tre quattro
  uno due tre quattro
  $ hg debugwireargs --ssh "python ./dummyssh" ssh://user@dummy/repo eins zwei --four vier
  eins zwei None vier
  $ hg debugwireargs --ssh "python ./dummyssh" ssh://user@dummy/repo eins zwei
  eins zwei None None