view tests/test-pull-pull-corruption.t @ 24429:69bd0ec2f9be

commands.push: abort when revisions evaluate to empty set (BC)

If the "-r" argument is specified to "hg push," the user has expressed
an intent for a specific changeset to be present on the remote. If that
expression cannot be mapped to a known changeset, the user's intent is
ambiguous and cannot be acted upon without making assumptions.

Previously, if arguments to `push -r <rev>` evaluated to an empty set
(perhaps the user specified a revset that didn't evaluate to anything),
the empty "revs" list would be passed down to "exchange.push" where
it appears the empty list was being interpreted as "push everything."

This patch adds validation to the "-r" argument to the push command. If
the argument is specified but doesn't resolve to a changeset, the
command will abort instead of doing something potentially unexpected.

This patch is technically breaking backwards compatibility. I believe
this is justified because the new behavior closes a crack that could
result in undefined or under-defined behavior. Also, this patch doesn't
drop client capabilities because if users really wanted to push all
changesets, they can simply omit the "-r" argument from push completely.

Corrupt an hg repo with two pulls.
create one repo with a long history

  $ hg init source1
  $ cd source1
  $ touch foo
  $ hg add foo
  $ for i in 1 2 3 4 5 6 7 8 9 10; do
  >     echo $i >> foo
  >     hg ci -m $i
  > done
  $ cd ..

create one repo with a shorter history

  $ hg clone -r 0 source1 source2
  adding changesets
  adding manifests
  adding file changes
  added 1 changesets with 1 changes to 1 files
  updating to branch default
  1 files updated, 0 files merged, 0 files removed, 0 files unresolved
  $ cd source2
  $ echo a >> foo
  $ hg ci -m a
  $ cd ..

create a third repo to pull both other repos into it

  $ hg init corrupted
  $ cd corrupted

use a hook to make the second pull start while the first one is still running

  $ echo '[hooks]' >> .hg/hgrc
  $ echo 'prechangegroup = sleep 5' >> .hg/hgrc

start a pull...

  $ hg pull ../source1 > pull.out 2>&1 &

... and start another pull before the first one has finished

  $ sleep 1
  $ hg pull ../source2 2>/dev/null
  pulling from ../source2
  searching for changes
  adding changesets
  adding manifests
  adding file changes
  added 1 changesets with 1 changes to 1 files (+1 heads)
  (run 'hg heads' to see heads, 'hg merge' to merge)
  $ cat pull.out
  pulling from ../source1
  requesting all changes
  adding changesets
  adding manifests
  adding file changes
  added 10 changesets with 10 changes to 1 files
  (run 'hg update' to get a working copy)

see the result

  $ wait
  $ hg verify
  checking changesets
  checking manifests
  crosschecking files in changesets and manifests
  checking files
  1 files, 11 changesets, 11 total revisions

  $ cd ..