view tests/test-addremove-similar.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 rep; cd rep

  $ touch empty-file
  $ "$PYTHON" -c 'for x in range(10000): print(x)' > large-file

  $ hg addremove
  adding empty-file
  adding large-file

  $ hg commit -m A

  $ rm large-file empty-file
  $ "$PYTHON" -c 'for x in range(10,10000): print(x)' > another-file

  $ hg addremove -s50
  adding another-file
  removing empty-file
  removing large-file
  recording removal of large-file as rename to another-file (99% similar)

  $ hg commit -m B

comparing two empty files caused ZeroDivisionError in the past

  $ hg update -C 0
  2 files updated, 0 files merged, 1 files removed, 0 files unresolved
  $ rm empty-file
  $ touch another-empty-file
  $ hg addremove -s50
  adding another-empty-file
  removing empty-file

  $ cd ..

  $ hg init rep2; cd rep2

  $ "$PYTHON" -c 'for x in range(10000): print(x)' > large-file
  $ "$PYTHON" -c 'for x in range(50): print(x)' > tiny-file

  $ hg addremove
  adding large-file
  adding tiny-file

  $ hg commit -m A

  $ "$PYTHON" -c 'for x in range(70): print(x)' > small-file
  $ rm tiny-file
  $ rm large-file

  $ hg addremove -s50
  removing large-file
  adding small-file
  removing tiny-file
  recording removal of tiny-file as rename to small-file (82% similar)

  $ hg commit -m B

should be sorted by path for stable result

  $ for i in `"$PYTHON" $TESTDIR/seq.py 0 9`; do
  >     cp small-file $i
  > done
  $ rm small-file
  $ hg addremove
  adding 0
  adding 1
  adding 2
  adding 3
  adding 4
  adding 5
  adding 6
  adding 7
  adding 8
  adding 9
  removing small-file
  recording removal of small-file as rename to 0 (100% similar)
  recording removal of small-file as rename to 1 (100% similar)
  recording removal of small-file as rename to 2 (100% similar)
  recording removal of small-file as rename to 3 (100% similar)
  recording removal of small-file as rename to 4 (100% similar)
  recording removal of small-file as rename to 5 (100% similar)
  recording removal of small-file as rename to 6 (100% similar)
  recording removal of small-file as rename to 7 (100% similar)
  recording removal of small-file as rename to 8 (100% similar)
  recording removal of small-file as rename to 9 (100% similar)
  $ hg commit -m '10 same files'

pick one from many identical files

  $ cp 0 a
  $ rm `"$PYTHON" $TESTDIR/seq.py 0 9`
  $ hg addremove
  removing 0
  removing 1
  removing 2
  removing 3
  removing 4
  removing 5
  removing 6
  removing 7
  removing 8
  removing 9
  adding a
  recording removal of 0 as rename to a (100% similar)
  $ hg revert -aq

pick one from many similar files

  $ cp 0 a
  $ for i in `"$PYTHON" $TESTDIR/seq.py 0 9`; do
  >     echo $i >> $i
  > done
  $ hg commit -m 'make them slightly different'
  $ rm `"$PYTHON" $TESTDIR/seq.py 0 9`
  $ hg addremove -s50
  removing 0
  removing 1
  removing 2
  removing 3
  removing 4
  removing 5
  removing 6
  removing 7
  removing 8
  removing 9
  adding a
  recording removal of 0 as rename to a (99% similar)
  $ hg commit -m 'always the same file should be selected'

should all fail

  $ hg addremove -s foo
  abort: similarity must be a number
  [10]
  $ hg addremove -s -1
  abort: similarity must be between 0 and 100
  [10]
  $ hg addremove -s 1e6
  abort: similarity must be between 0 and 100
  [10]

  $ cd ..

Issue1527: repeated addremove causes Abort

  $ hg init rep3; cd rep3
  $ mkdir d
  $ echo a > d/a
  $ hg add d/a
  $ hg commit -m 1

  $ mv d/a d/b
  $ hg addremove -s80
  removing d/a
  adding d/b
  recording removal of d/a as rename to d/b (100% similar)
  $ hg debugstate
  r   0          0 1970-01-01 00:00:00 d/a
  a   0         -1 unset               d/b
  copy: d/a -> d/b
  $ mv d/b c

no copies found here (since the target isn't in d

  $ hg addremove -s80 d
  removing d/b

copies here

  $ hg addremove -s80
  adding c
  recording removal of d/a as rename to c (100% similar)

  $ cd ..