view tests/test-mq-qrefresh-replace-log-message.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.

Environement setup for MQ

  $ echo "[extensions]" >> $HGRCPATH
  $ echo "mq=" >> $HGRCPATH
  $ hg init
  $ hg qinit

Should fail if no patches applied

  $ hg qrefresh
  no patches applied
  [1]
  $ hg qrefresh -e
  no patches applied
  [1]
  $ hg qnew -m "First commit message" first-patch
  $ echo aaaa > file
  $ hg add file
  $ hg qrefresh

Should display 'First commit message'

  $ hg log -l1 --template "{desc}\n"
  First commit message

Testing changing message with -m

  $ echo bbbb > file
  $ hg qrefresh -m "Second commit message"

Should display 'Second commit message'

  $ hg log -l1 --template "{desc}\n"
  Second commit message

Testing changing message with -l

  $ echo "Third commit message" > logfile
  $ echo " This is the 3rd log message" >> logfile
  $ echo bbbb > file
  $ hg qrefresh -l logfile

Should display 'Third commit message\\\n This is the 3rd log message'

  $ hg log -l1 --template "{desc}\n"
  Third commit message
   This is the 3rd log message

Testing changing message with -l-

  $ hg qnew -m "First commit message" second-patch
  $ echo aaaa > file2
  $ hg add file2
  $ echo bbbb > file2
  $ (echo "Fifth commit message"; echo " This is the 5th log message") | hg qrefresh -l-

Should display 'Fifth commit message\\\n This is the 5th log message'

  $ hg log -l1 --template "{desc}\n"
  Fifth commit message
   This is the 5th log message