view tests/test-eol-add.t @ 42377:0546ead39a7e stable

manifest: avoid corruption by dropping removed files with pure (issue5801)

Previously, removed files would simply be marked by overwriting the first byte
with NUL and dropping their entry in `self.position`.  But no effort was made to
ignore them when compacting the dictionary into text form.  This allowed them to
slip into the manifest revision, since the code seems to be trying to minimize
the string operations by copying as large a chunk as possible.  As part of this,
compact() walks the existing text based on entries in the `positions` list, and
consumed everything up to the next position entry.   This typically resulted in
a ValueError complaining about unsorted manifest entries.

Sometimes it seems that files do get dropped in large repos- it seems to
correspond to there being a new entry that would take the same slot.  A much
more trivial problem is that if the only changes were removals, `_compact()`
didn't even run because `__delitem__` doesn't add anything to `self.extradata`.
Now there's an explicit variable to flag this, both to allow `_compact()` to
run, and to avoid searching the manifest in cases where there are no removals.

In practice, this behavior was mostly obscured by the check in fastdelta() which
takes a different path that explicitly drops removed files if there are fewer
than 1000 changes.  However, timeless has a repo where after rebasing tens of
commits, a totally different path[1] is taken that bypasses the change count
check and hits this problem.

[1] https://www.mercurial-scm.org/repo/hg/file/2338bdea4474/mercurial/manifest.py#l1511

Test adding .hgeol

  $ 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
  >     printf "first\nsecond\nthird\n" > a.txt
  >     hg commit -d '100 0' --addremove -m 'LF commit'
  >     cd ..
  > }
  $ dotest () {
  >     seteol $1
  >     echo
  >     echo "% hg clone repo repo-$1"
  >     hg clone repo repo-$1
  >     cd repo-$1
  >     cat > .hg/hgrc <<EOF
  > [extensions]
  > eol =
  > [eol]
  > native = LF
  > EOF
  >     cat > .hgeol <<EOF
  > [patterns]
  > **.txt = native
  > [repository]
  > native = $1
  > EOF
  >     echo '% hg add .hgeol'
  >     hg add .hgeol
  >     echo '% hg status'
  >     hg status
  >     echo '% hg commit'
  >     hg commit -d '200 0' -m 'Added .hgeol file'
  >     echo '% hg status'
  >     hg status
  >     echo '% hg tip -p'
  >     hg tip -p
  >     cd ..
  >     rm -r repo-$1
  > }
  $ makerepo
  
  # ==== setup repository ====
  % hg init
  adding a.txt
  $ dotest LF
  
  % hg clone repo repo-LF
  updating to branch default
  1 files updated, 0 files merged, 0 files removed, 0 files unresolved
  % hg add .hgeol
  % hg status
  A .hgeol
  % hg commit
  % hg status
  % hg tip -p
  changeset:   1:33503edb53b0
  tag:         tip
  user:        test
  date:        Thu Jan 01 00:03:20 1970 +0000
  summary:     Added .hgeol file
  
  diff --git a/.hgeol b/.hgeol
  new file mode 100644
  --- /dev/null
  +++ b/.hgeol
  @@ -0,0 +1,4 @@
  +[patterns]
  +**.txt = native
  +[repository]
  +native = LF
  
  $ dotest CRLF
  
  % hg clone repo repo-CRLF
  updating to branch default
  1 files updated, 0 files merged, 0 files removed, 0 files unresolved
  % hg add .hgeol
  % hg status
  M a.txt
  A .hgeol
  % hg commit
  % hg status
  % hg tip -p
  changeset:   1:6e64eaa9eb23
  tag:         tip
  user:        test
  date:        Thu Jan 01 00:03:20 1970 +0000
  summary:     Added .hgeol file
  
  diff --git a/.hgeol b/.hgeol
  new file mode 100644
  --- /dev/null
  +++ b/.hgeol
  @@ -0,0 +1,4 @@
  +[patterns]
  +**.txt = native
  +[repository]
  +native = CRLF
  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)
  
  $ rm -r repo