tests/test-diff-hashes.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).

  $ hg init a
  $ cd a

  $ hg diff inexistent1 inexistent2
  inexistent1: * (glob)
  inexistent2: * (glob)

  $ echo bar > foo
  $ hg add foo
  $ hg ci -m 'add foo'

  $ echo foobar > foo
  $ hg ci -m 'change foo'

  $ hg --quiet diff -r 0 -r 1
  --- a/foo	Thu Jan 01 00:00:00 1970 +0000
  +++ b/foo	Thu Jan 01 00:00:00 1970 +0000
  @@ -1,1 +1,1 @@
  -bar
  +foobar

  $ hg diff -r 0 -r 1
  diff -r a99fb63adac3 -r 9b8568d3af2f foo
  --- a/foo	Thu Jan 01 00:00:00 1970 +0000
  +++ b/foo	Thu Jan 01 00:00:00 1970 +0000
  @@ -1,1 +1,1 @@
  -bar
  +foobar

  $ hg --verbose diff -r 0 -r 1
  diff -r a99fb63adac3 -r 9b8568d3af2f foo
  --- a/foo	Thu Jan 01 00:00:00 1970 +0000
  +++ b/foo	Thu Jan 01 00:00:00 1970 +0000
  @@ -1,1 +1,1 @@
  -bar
  +foobar

  $ hg --debug diff -r 0 -r 1
  diff -r a99fb63adac3f31816a22f665bc3b7a7655b30f4 -r 9b8568d3af2f1749445eef03aede868a6f39f210 foo
  --- a/foo	Thu Jan 01 00:00:00 1970 +0000
  +++ b/foo	Thu Jan 01 00:00:00 1970 +0000
  @@ -1,1 +1,1 @@
  -bar
  +foobar