tests/test-pull-pull-corruption.t

commit: abort on merge with missing files

Here is a script illustrating the previous behaviour:

The merge brings a new file 'b' from remote
  $ hg merge 1 --debug
    searching for copies back to rev 1
    unmatched files in other:
     b
  resolving manifests
   overwrite: False, partial: False
   ancestor: 07f494440405, local: 540395c44225+, remote: 102a90ea7b4a
   b: remote created -> g
  updating: b 1/1 files (100.00%)
  getting b
  1 files updated, 0 files merged, 0 files removed, 0 files unresolved
  (branch merge, don't forget to commit)

Delete but do not remove b
  $ rm b
  $ hg st
  ! b

The commit succeeds
  $ hg commit -m merge
  $ hg parents --template "{rev} {desc|firstline} files: {files}\n"
  3 merge files:
  $ hg st
  ! b

b changes were ignored, but even b existence was ignored
  $ hg manifest
  a

This happens because localrepo.commitctx() checks the input ctx.files(), which
is empty for workingctx.files() only returns added, modified or removed
entries, and bypass files/manifest updates completely. So the committed
revision manifest is the same as its first parent one, not containing the 'b'
file.

This patch forces the commit to abort in presence of a merge and missing files.
test-merge4.t is modified accordingly as it was introduced to check hg was not
just terminating with a traceback (5e9e8b8d2629).

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