view tests/test-convert-hg-startrev.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.

  $ cat >> $HGRCPATH <<EOF
  > [extensions]
  > graphlog =
  > convert =
  > [convert]
  > hg.saverev = yes
  > EOF

  $ glog()
  > {
  >     hg -R "$1" glog --template '{rev} "{desc}" files: {files}\n'
  > }

  $ hg init source
  $ cd source

  $ echo a > a
  $ echo b > b
  $ hg ci -d '0 0' -qAm '0: add a b'
  $ echo c > c
  $ hg ci -d '1 0' -qAm '1: add c'
  $ hg copy a e
  $ echo b >> b
  $ hg ci -d '2 0' -qAm '2: copy e from a, change b'
  $ hg up -C 0
  1 files updated, 0 files merged, 2 files removed, 0 files unresolved
  $ echo a >> a
  $ hg ci -d '3 0' -qAm '3: change a'
  $ hg merge
  merging a and e to e
  2 files updated, 1 files merged, 0 files removed, 0 files unresolved
  (branch merge, don't forget to commit)
  $ hg copy b d
  $ hg ci -d '4 0' -qAm '4: merge 2 and 3, copy d from b'
  $ echo a >> a
  $ hg ci -d '5 0' -qAm '5: change a'
  $ cd ..

Convert from null revision

  $ hg convert --config convert.hg.startrev=null source full
  initializing destination full repository
  scanning source...
  sorting...
  converting...
  5 0: add a b
  4 1: add c
  3 2: copy e from a, change b
  2 3: change a
  1 4: merge 2 and 3, copy d from b
  0 5: change a

  $ glog full
  o  5 "5: change a" files: a
  |
  o    4 "4: merge 2 and 3, copy d from b" files: d e
  |\
  | o  3 "3: change a" files: a
  | |
  o |  2 "2: copy e from a, change b" files: b e
  | |
  o |  1 "1: add c" files: c
  |/
  o  0 "0: add a b" files: a b
  
  $ rm -Rf full

Convert from zero revision

  $ hg convert --config convert.hg.startrev=0 source full
  initializing destination full repository
  scanning source...
  sorting...
  converting...
  5 0: add a b
  4 1: add c
  3 2: copy e from a, change b
  2 3: change a
  1 4: merge 2 and 3, copy d from b
  0 5: change a

  $ glog full
  o  5 "5: change a" files: a
  |
  o    4 "4: merge 2 and 3, copy d from b" files: d e
  |\
  | o  3 "3: change a" files: a
  | |
  o |  2 "2: copy e from a, change b" files: b e
  | |
  o |  1 "1: add c" files: c
  |/
  o  0 "0: add a b" files: a b
  
Convert from merge parent

  $ hg convert --config convert.hg.startrev=1 source conv1
  initializing destination conv1 repository
  scanning source...
  sorting...
  converting...
  3 1: add c
  2 2: copy e from a, change b
  1 4: merge 2 and 3, copy d from b
  0 5: change a

  $ glog conv1
  o  3 "5: change a" files: a
  |
  o  2 "4: merge 2 and 3, copy d from b" files: a d e
  |
  o  1 "2: copy e from a, change b" files: b e
  |
  o  0 "1: add c" files: a b c
  
  $ cd conv1

Check copy preservation

  $ hg log --follow --copies e
  changeset:   2:79818a521a40
  user:        test
  date:        Thu Jan 01 00:00:04 1970 +0000
  summary:     4: merge 2 and 3, copy d from b
  
  changeset:   1:3e6201832cce
  user:        test
  date:        Thu Jan 01 00:00:02 1970 +0000
  summary:     2: copy e from a, change b
  
Check copy removal on missing parent

  $ hg log --follow --copies d
  changeset:   2:79818a521a40
  user:        test
  date:        Thu Jan 01 00:00:04 1970 +0000
  summary:     4: merge 2 and 3, copy d from b
  
  $ hg cat -r tip a b
  a
  a
  a
  b
  b
  $ hg -q verify
  $ cd ..

Convert from merge

  $ hg convert --config convert.hg.startrev=4 source conv4
  initializing destination conv4 repository
  scanning source...
  sorting...
  converting...
  1 4: merge 2 and 3, copy d from b
  0 5: change a
  $ glog conv4
  o  1 "5: change a" files: a
  |
  o  0 "4: merge 2 and 3, copy d from b" files: a b c d e
  
  $ cd conv4
  $ hg up -C
  5 files updated, 0 files merged, 0 files removed, 0 files unresolved
  $ hg cat -r tip a b
  a
  a
  a
  b
  b
  $ hg -q verify
  $ cd ..