view tests/test-eol-update.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

Test EOL update

  $ cat >> $HGRCPATH <<EOF
  > [diff]
  > git = 1
  > EOF

  $ seteol () {
  >     if [ $1 = "LF" ]; then
  >         EOL='\n'
  >     else
  >         EOL='\r\n'
  >     fi
  > }

  $ makerepo () {
  >     echo
  >     echo "# ==== setup repository ===="
  >     echo '% hg init'
  >     hg init repo
  >     cd repo
  > 
  >     cat > .hgeol <<EOF
  > [patterns]
  > **.txt = LF
  > EOF
  > 
  >     printf "first\nsecond\nthird\n" > a.txt
  >     printf "f\r\n" > f
  >     hg commit --addremove -m 'LF commit'
  > 
  >     cat > .hgeol <<EOF
  > [patterns]
  > **.txt = CRLF
  > f = LF
  > EOF
  > 
  >     printf "first\r\nsecond\r\nthird\r\n" > a.txt
  >     printf "f\n" > f
  >     hg commit -m 'CRLF commit'
  > 
  >     cd ..
  > }

  $ dotest () {
  >     seteol $1
  > 
  >     echo
  >     echo "% hg clone repo repo-$1"
  >     hg clone --noupdate repo repo-$1
  >     cd repo-$1
  > 
  >     cat > .hg/hgrc <<EOF
  > [extensions]
  > eol =
  > EOF
  > 
  >     hg update
  > 
  >     echo '% a.txt (before)'
  >     cat a.txt
  > 
  >     printf "first${EOL}third${EOL}" > a.txt
  > 
  >     echo '% a.txt (after)'
  >     cat a.txt
  >     echo '% hg diff'
  >     hg diff
  > 
  >     echo '% hg update 0'
  >     hg update 0
  > 
  >     echo '% a.txt'
  >     cat a.txt
  >     echo '% hg diff'
  >     hg diff
  > 
  > 
  >     cd ..
  >     rm -r repo-$1
  > }

  $ makerepo
  
  # ==== setup repository ====
  % hg init
  adding .hgeol
  adding a.txt
  adding f
  $ dotest LF
  
  % hg clone repo repo-LF
  3 files updated, 0 files merged, 0 files removed, 0 files unresolved
  % a.txt (before)
  first\r (esc)
  second\r (esc)
  third\r (esc)
  % a.txt (after)
  first
  third
  % hg diff
  diff --git a/a.txt b/a.txt
  --- a/a.txt
  +++ b/a.txt
  @@ -1,3 +1,2 @@
   first\r (esc)
  -second\r (esc)
   third\r (esc)
  % hg update 0
  merging a.txt
  2 files updated, 1 files merged, 0 files removed, 0 files unresolved
  % a.txt
  first
  third
  % hg diff
  diff --git a/a.txt b/a.txt
  --- a/a.txt
  +++ b/a.txt
  @@ -1,3 +1,2 @@
   first
  -second
   third
  $ dotest CRLF
  
  % hg clone repo repo-CRLF
  3 files updated, 0 files merged, 0 files removed, 0 files unresolved
  % a.txt (before)
  first\r (esc)
  second\r (esc)
  third\r (esc)
  % a.txt (after)
  first\r (esc)
  third\r (esc)
  % hg diff
  diff --git a/a.txt b/a.txt
  --- a/a.txt
  +++ b/a.txt
  @@ -1,3 +1,2 @@
   first\r (esc)
  -second\r (esc)
   third\r (esc)
  % hg update 0
  merging a.txt
  2 files updated, 1 files merged, 0 files removed, 0 files unresolved
  % a.txt
  first
  third
  % hg diff
  diff --git a/a.txt b/a.txt
  --- a/a.txt
  +++ b/a.txt
  @@ -1,3 +1,2 @@
   first
  -second
   third

Test in repo using eol extension, while keeping an eye on how filters are
applied:

  $ cd repo

  $ hg up -q -c -r null
  $ cat > .hg/hgrc <<EOF
  > [extensions]
  > eol =
  > EOF

Update to revision 0 which has no .hgeol, shouldn't use any filters, and
obviously should leave things as tidy as they were before the clean update.

  $ hg up -c -r 0 -v --debug
  resolving manifests
   branchmerge: False, force: False, partial: False
   ancestor: 000000000000, local: 000000000000+, remote: 15cbdf8ca3db
  calling hook preupdate.eol: hgext.eol.preupdate
   .hgeol: remote created -> g
  getting .hgeol
  filtering .hgeol through isbinary
   a.txt: remote created -> g
  getting a.txt
  filtering a.txt through tolf
   f: remote created -> g
  getting f
  3 files updated, 0 files merged, 0 files removed, 0 files unresolved
  $ hg st

  $ hg branch b
  marked working directory as branch b
  (branches are permanent and global, did you want a bookmark?)
  $ hg ci -m b

Merge changes that apply a filter to f:

  $ hg merge 1
  3 files updated, 0 files merged, 0 files removed, 0 files unresolved
  (branch merge, don't forget to commit)
  $ hg st
  M .hgeol
  M a.txt
  M f
  $ hg diff
  diff --git a/.hgeol b/.hgeol
  --- a/.hgeol
  +++ b/.hgeol
  @@ -1,2 +1,3 @@
   [patterns]
  -**.txt = LF
  +**.txt = CRLF
  +f = LF
  diff --git a/a.txt b/a.txt
  --- a/a.txt
  +++ b/a.txt
  @@ -1,3 +1,3 @@
  -first
  -second
  -third
  +first\r (esc)
  +second\r (esc)
  +third\r (esc)
  diff --git a/f b/f
  --- a/f
  +++ b/f
  @@ -1,1 +1,1 @@
  -f\r (esc)
  +f

Abort the merge with up -C to revision 0.
Note that files are filtered correctly for revision 0: f is not filtered, a.txt
is filtered with tolf, and everything is left tidy.

  $ touch .hgeol *  # ensure consistent dirtyness checks ignoring dirstate
  $ hg up -C -r 0 -v --debug
  eol: detected change in .hgeol
  resolving manifests
   branchmerge: False, force: True, partial: False
   ancestor: 1db78bdd3bd6+, local: 1db78bdd3bd6+, remote: 15cbdf8ca3db
  calling hook preupdate.eol: hgext.eol.preupdate
   .hgeol: remote is newer -> g
  getting .hgeol
  filtering .hgeol through isbinary
   a.txt: remote is newer -> g
  getting a.txt
  filtering a.txt through tolf
   f: remote is newer -> g
  getting f
  3 files updated, 0 files merged, 0 files removed, 0 files unresolved

  $ touch .hgeol *
  $ hg st --debug
  eol: detected change in .hgeol
  filtering .hgeol through isbinary
  filtering a.txt through tolf
  skip updating dirstate: identity mismatch (?)
  $ hg diff

Things were clean, and updating again will not change anything:

  $ touch .hgeol *
  $ hg up -C -r 0 -v --debug
  eol: detected change in .hgeol
  filtering .hgeol through isbinary
  filtering a.txt through tolf
  resolving manifests
   branchmerge: False, force: True, partial: False
   ancestor: 15cbdf8ca3db+, local: 15cbdf8ca3db+, remote: 15cbdf8ca3db
  calling hook preupdate.eol: hgext.eol.preupdate
  starting 4 threads for background file closing (?)
  0 files updated, 0 files merged, 0 files removed, 0 files unresolved

  $ touch .hgeol *
  $ hg st --debug
  eol: detected change in .hgeol
  filtering .hgeol through isbinary
  filtering a.txt through tolf

  $ cd ..

  $ rm -r repo