view tests/test-win32text.t @ 48507:58a3be48ddd2

simplemerge: stop merging file flags

As 384df4db6520 (merge: merge file flags together with file content,
2013-01-09) explains, we shouldn't do a 3-way merge of the
symlink. However, since 84614212ae39 (flags: actually merge flags in
simplemerge, 2020-05-16), we do that in
`simplemerge.simplemerge()`. What's more, the merging of the
executable flag there isn't actually necessary; it was made a no-op by
the very next commit, i.e. 4234c9af515d (flags: read flag from
dirstate/disk for workingcopyctx (issue5743), 2020-05-16).

I found the overall flag-merging code (not the bit in
`simplemerge.py`) very hard to follow, but I think I now finally
understand how it works. `mergestate.resolve()` calculates the merged
file flags and sets them on the local side of the merge (confusingly
by calling `_restore_backup()`). Then it calls
`filemerge.filemerge()`, which in turn calls
`simplemerge.simplemerge()` (if premerge is enabled). That means that
the flags on the local side `fcs.flags()` are already correct when the
flag-merging code in `simplemerge.simplemerge()` runs. Interestingly,
that code still works when the local side already has the merged
value, it just doesn't change the value. Here's a truth table to
explain why:

```
BLOMCAR
0000000
0011111
0101011
0111111
1000000
1010000
1100000
1111101
```

B: Base
L: Local
O: Other
M: Merged flags from `mergestate.resolve()`, i.e. what's called "local"
   when we get to `simplemerge.simplemerge()`
C: `commonflags` in `simplemerge.simplemerge()`, i.e. `M & O`
A: `addedflags` in `simplemerge.simplemerge()`, i.e. `(M ^ O) - B`
R: Re-merged flags `simplemerge.simplemerge()`, i.e. `C | A`

As you can see, the re-merged flags are always unchanged compared to
the initial merged flags (R equals M).

Therefore, this patch effectively backs out 84614212ae39. (I might
later refactor this code to have the flags explicitly passed in.)

`simplemerge.simplemerge()` is also called from
`contrib/simplemerge.py`, but that code never passes any flags.

Differential Revision: https://phab.mercurial-scm.org/D11879

  $ hg init t
  $ cd t
  $ cat > unix2dos.py <<EOF
  > import sys
  > 
  > for path in sys.argv[1:]:
  >     data = open(path, 'rb').read()
  >     data = data.replace(b'\n', b'\r\n')
  >     open(path, 'wb').write(data)
  > EOF
  $ echo '[hooks]' >> .hg/hgrc
  $ echo 'pretxncommit.crlf = python:hgext.win32text.forbidcrlf' >> .hg/hgrc
  $ echo 'pretxnchangegroup.crlf = python:hgext.win32text.forbidcrlf' >> .hg/hgrc
  $ cat .hg/hgrc
  [hooks]
  pretxncommit.crlf = python:hgext.win32text.forbidcrlf
  pretxnchangegroup.crlf = python:hgext.win32text.forbidcrlf

  $ echo hello > f
  $ hg add f

commit should succeed

  $ hg ci -m 1

  $ hg clone . ../zoz
  updating to branch default
  1 files updated, 0 files merged, 0 files removed, 0 files unresolved
  $ cp .hg/hgrc ../zoz/.hg
  $ "$PYTHON" unix2dos.py f

commit should fail

  $ hg ci -m 2.1
  attempt to commit or push text file(s) using CRLF line endings
  in f583ea08d42a: f
  transaction abort!
  rollback completed
  abort: pretxncommit.crlf hook failed
  [40]

  $ mv .hg/hgrc .hg/hgrc.bak

commits should succeed

  $ hg ci -m 2
  $ hg cp f g
  $ hg ci -m 2.2

push should fail

  $ hg push ../zoz
  pushing to ../zoz
  searching for changes
  adding changesets
  adding manifests
  adding file changes
  attempt to commit or push text file(s) using CRLF line endings
  in bc2d09796734: g
  in b1aa5cde7ff4: f
  
  To prevent this mistake in your local repository,
  add to Mercurial.ini or .hg/hgrc:
  
  [hooks]
  pretxncommit.crlf = python:hgext.win32text.forbidcrlf
  
  and also consider adding:
  
  [extensions]
  win32text =
  [encode]
  ** = cleverencode:
  [decode]
  ** = cleverdecode:
  transaction abort!
  rollback completed
  abort: pretxnchangegroup.crlf hook failed
  [40]

  $ mv .hg/hgrc.bak .hg/hgrc
  $ echo hello > f
  $ hg rm g

commit should succeed

  $ hg ci -m 2.3

push should succeed

  $ hg push ../zoz
  pushing to ../zoz
  searching for changes
  adding changesets
  adding manifests
  adding file changes
  added 3 changesets with 3 changes to 2 files

and now for something completely different

  $ mkdir d
  $ echo hello > d/f2
  $ "$PYTHON" unix2dos.py d/f2
  $ hg add d/f2
  $ hg ci -m 3
  attempt to commit or push text file(s) using CRLF line endings
  in 053ba1a3035a: d/f2
  transaction abort!
  rollback completed
  abort: pretxncommit.crlf hook failed
  [40]
  $ hg revert -a
  forgetting d/f2
  $ rm d/f2

  $ hg rem f
  $ hg ci -m 4

  $ "$PYTHON" -c 'open("bin", "wb").write(b"hello\x00\x0D\x0A")'
  $ hg add bin
  $ hg ci -m 5
  $ hg log -v
  changeset:   5:f0b1c8d75fce
  tag:         tip
  user:        test
  date:        Thu Jan 01 00:00:00 1970 +0000
  files:       bin
  description:
  5
  
  
  changeset:   4:77796dbcd4ad
  user:        test
  date:        Thu Jan 01 00:00:00 1970 +0000
  files:       f
  description:
  4
  
  
  changeset:   3:7c1b5430b350
  user:        test
  date:        Thu Jan 01 00:00:00 1970 +0000
  files:       f g
  description:
  2.3
  
  
  changeset:   2:bc2d09796734
  user:        test
  date:        Thu Jan 01 00:00:00 1970 +0000
  files:       g
  description:
  2.2
  
  
  changeset:   1:b1aa5cde7ff4
  user:        test
  date:        Thu Jan 01 00:00:00 1970 +0000
  files:       f
  description:
  2
  
  
  changeset:   0:fcf06d5c4e1d
  user:        test
  date:        Thu Jan 01 00:00:00 1970 +0000
  files:       f
  description:
  1
  
  
  $ hg clone . dupe
  updating to branch default
  1 files updated, 0 files merged, 0 files removed, 0 files unresolved

  $ for x in a b c d; do echo content > dupe/$x; done
  $ hg -R dupe add
  adding dupe/a
  adding dupe/b
  adding dupe/c
  adding dupe/d
  $ "$PYTHON" unix2dos.py dupe/b dupe/c dupe/d
  $ hg -R dupe ci -m a dupe/a
  $ hg -R dupe ci -m b/c dupe/[bc]
  $ hg -R dupe ci -m d dupe/d
  $ hg -R dupe log -v
  changeset:   8:67ac5962ab43
  tag:         tip
  user:        test
  date:        Thu Jan 01 00:00:00 1970 +0000
  files:       d
  description:
  d
  
  
  changeset:   7:68c127d1834e
  user:        test
  date:        Thu Jan 01 00:00:00 1970 +0000
  files:       b c
  description:
  b/c
  
  
  changeset:   6:adbf8bf7f31d
  user:        test
  date:        Thu Jan 01 00:00:00 1970 +0000
  files:       a
  description:
  a
  
  
  changeset:   5:f0b1c8d75fce
  user:        test
  date:        Thu Jan 01 00:00:00 1970 +0000
  files:       bin
  description:
  5
  
  
  changeset:   4:77796dbcd4ad
  user:        test
  date:        Thu Jan 01 00:00:00 1970 +0000
  files:       f
  description:
  4
  
  
  changeset:   3:7c1b5430b350
  user:        test
  date:        Thu Jan 01 00:00:00 1970 +0000
  files:       f g
  description:
  2.3
  
  
  changeset:   2:bc2d09796734
  user:        test
  date:        Thu Jan 01 00:00:00 1970 +0000
  files:       g
  description:
  2.2
  
  
  changeset:   1:b1aa5cde7ff4
  user:        test
  date:        Thu Jan 01 00:00:00 1970 +0000
  files:       f
  description:
  2
  
  
  changeset:   0:fcf06d5c4e1d
  user:        test
  date:        Thu Jan 01 00:00:00 1970 +0000
  files:       f
  description:
  1
  
  
  $ hg pull dupe
  pulling from dupe
  searching for changes
  adding changesets
  adding manifests
  adding file changes
  attempt to commit or push text file(s) using CRLF line endings
  in 67ac5962ab43: d
  in 68c127d1834e: b
  in 68c127d1834e: c
  
  To prevent this mistake in your local repository,
  add to Mercurial.ini or .hg/hgrc:
  
  [hooks]
  pretxncommit.crlf = python:hgext.win32text.forbidcrlf
  
  and also consider adding:
  
  [extensions]
  win32text =
  [encode]
  ** = cleverencode:
  [decode]
  ** = cleverdecode:
  transaction abort!
  rollback completed
  abort: pretxnchangegroup.crlf hook failed
  [40]

  $ hg log -v
  changeset:   5:f0b1c8d75fce
  tag:         tip
  user:        test
  date:        Thu Jan 01 00:00:00 1970 +0000
  files:       bin
  description:
  5
  
  
  changeset:   4:77796dbcd4ad
  user:        test
  date:        Thu Jan 01 00:00:00 1970 +0000
  files:       f
  description:
  4
  
  
  changeset:   3:7c1b5430b350
  user:        test
  date:        Thu Jan 01 00:00:00 1970 +0000
  files:       f g
  description:
  2.3
  
  
  changeset:   2:bc2d09796734
  user:        test
  date:        Thu Jan 01 00:00:00 1970 +0000
  files:       g
  description:
  2.2
  
  
  changeset:   1:b1aa5cde7ff4
  user:        test
  date:        Thu Jan 01 00:00:00 1970 +0000
  files:       f
  description:
  2
  
  
  changeset:   0:fcf06d5c4e1d
  user:        test
  date:        Thu Jan 01 00:00:00 1970 +0000
  files:       f
  description:
  1
  
  
  $ rm .hg/hgrc
  $ (echo some; echo text) > f3
  $ "$PYTHON" -c 'open("f4.bat", "wb").write(b"rem empty\x0D\x0A")'
  $ hg add f3 f4.bat
  $ hg ci -m 6
  $ cat bin
  hello\x00\r (esc)
  $ cat f3
  some
  text
  $ cat f4.bat
  rem empty\r (esc)

  $ echo '[extensions]' >> .hg/hgrc
  $ echo 'win32text = ' >> .hg/hgrc
  $ echo '[decode]' >> .hg/hgrc
  $ echo '** = cleverdecode:' >> .hg/hgrc
  $ echo '[encode]' >> .hg/hgrc
  $ echo '** = cleverencode:' >> .hg/hgrc
  $ cat .hg/hgrc
  [extensions]
  win32text = 
  [decode]
  ** = cleverdecode:
  [encode]
  ** = cleverencode:

Trigger deprecation warning:

  $ hg id -t
  win32text is deprecated: https://mercurial-scm.org/wiki/Win32TextExtension
  tip

Disable warning:

  $ echo '[win32text]' >> .hg/hgrc
  $ echo 'warn = no' >> .hg/hgrc
  $ hg id -t
  tip

  $ rm f3 f4.bat bin
  $ hg co -C
  WARNING: f4.bat already has CRLF line endings
  and does not need EOL conversion by the win32text plugin.
  Before your next commit, please reconsider your encode/decode settings in 
  Mercurial.ini or $TESTTMP/t/.hg/hgrc.
  3 files updated, 0 files merged, 0 files removed, 0 files unresolved
  $ cat bin
  hello\x00\r (esc)
  $ cat f3
  some\r (esc)
  text\r (esc)
  $ cat f4.bat
  rem empty\r (esc)

  $ "$PYTHON" -c 'open("f5.sh", "wb").write(b"# empty\x0D\x0A")'
  $ hg add f5.sh
  $ hg ci -m 7
  $ cat f5.sh
  # empty\r (esc)
  $ hg cat f5.sh
  # empty
  $ echo '% just linefeed' > linefeed
  $ hg ci -qAm 8 linefeed
  $ cat linefeed
  % just linefeed
  $ hg cat linefeed
  % just linefeed
  $ hg st -q
  $ hg revert -a linefeed
  no changes needed to linefeed
  $ cat linefeed
  % just linefeed
  $ hg st -q
  $ echo modified >> linefeed
  $ hg st -q
  M linefeed
  $ hg revert -a
  reverting linefeed
  $ hg st -q
  $ cat linefeed
  % just linefeed\r (esc)

  $ cd ..