tests/test-merge-remove.t

filemerge: make last line of prompts <40 english chars (issue6158)

I've chosen <40 as the target so that other languages that may have a 2x blowup
in character count can still have a chance to fit into an 80 column screen.

Previously, we would show a prompt like:

```
keep (l)ocal [dest], take (o)ther [source], or leave (u)nresolved for some/potentially/really/long/path?
```

On at least some systems, if readline was in use then the last line of the
prompt would be wrapped strangely if it couldn't fit entirely on one line. This
strange wrapping may be just a carriage return without a line feed, overwriting
the beginning of the line; example (100 columns wide, 65 character filename, and
yes there's 10 spaces on the end, I assume this is to handle the user inputting
longest word we provide as an option, "unresolved"):

```
ng/dir/name/that/does/not/work/well/with/readline/file.txt? ave (u)nresolved for some/lon
```

In some cases it may partially wrap onto the next line, but still be missing
earlier parts in the line, such as below (60 columns wide, 65 character
filename):

```
 rev], or leave (u)nresolved for some/long/dir/name/that/do
s/not/work/well/with/readline/file.txt?
```

With this fix, this looks like this on a 60 column screen:

```
tool vim_with_markers (for pattern some/long/dir/name/that/d
oes/not/work/well/with/readline/file.txt) can't handle binar
y
tool meld can't handle binary
tool vim_with_markers can't handle binary
tool internal:merge3 can't handle binary
tool merge can't handle binary
no tool found to merge some/long/dir/name/that/does/not/work
/well/with/readline/file.txt
file 'some/long/dir/name/that/does/not/work/well/with/readli
ne/file.txt' needs to be resolved.
You can keep (l)ocal [working copy], take (o)ther [merge rev
], or leave (u)nresolved.
What do you want to do?
```

Differential Revision: https://phab.mercurial-scm.org/D6562

  $ hg init

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

  $ echo foo2 >> foo
  $ echo bleh > bar
  $ hg ci -m 'change foo bar'

  $ hg up -qC 0
  $ hg mv foo foo1
  $ echo foo1 > foo1
  $ hg cat foo >> foo1
  $ hg ci -m 'mv foo foo1'
  created new head

  $ hg merge
  merging foo1 and foo to foo1
  1 files updated, 1 files merged, 0 files removed, 0 files unresolved
  (branch merge, don't forget to commit)

  $ hg debugstate --no-dates
  m   0         -2 unset               bar
  m   0         -2 unset               foo1
  copy: foo -> foo1

  $ hg st -q
  M bar
  M foo1


Removing foo1 and bar:

  $ cp foo1 F
  $ cp bar B
  $ hg rm -f foo1 bar

  $ hg debugstate --no-dates
  r   0         -1 set                 bar
  r   0         -1 set                 foo1
  copy: foo -> foo1

  $ hg st -qC
  R bar
  R foo1


Re-adding foo1 and bar:

  $ cp F foo1
  $ cp B bar
  $ hg add -v foo1 bar
  adding bar
  adding foo1

  $ hg debugstate --no-dates
  n   0         -2 unset               bar
  n   0         -2 unset               foo1
  copy: foo -> foo1

  $ hg st -qC
  M bar
  M foo1
    foo


Reverting foo1 and bar:

  $ hg revert -vr . foo1 bar
  saving current version of bar as bar.orig
  saving current version of foo1 as foo1.orig
  reverting bar
  reverting foo1

  $ hg debugstate --no-dates
  n   0         -2 unset               bar
  n   0         -2 unset               foo1
  copy: foo -> foo1

  $ hg st -qC
  M bar
  M foo1
    foo

  $ hg diff

Merge should not overwrite local file that is untracked after remove

  $ rm *
  $ hg up -qC
  $ hg rm bar
  $ hg ci -m 'remove bar'
  $ echo 'memories of buried pirate treasure' > bar
  $ hg merge
  bar: untracked file differs
  abort: untracked files in working directory differ from files in requested revision
  [255]
  $ cat bar
  memories of buried pirate treasure

Those who use force will lose

  $ hg merge -f
  file 'bar' was deleted in local [working copy] but was modified in other [merge rev].
  You can use (c)hanged version, leave (d)eleted, or leave (u)nresolved.
  What do you want to do? u
  merging foo1 and foo to foo1
  0 files updated, 1 files merged, 0 files removed, 1 files unresolved
  use 'hg resolve' to retry unresolved file merges or 'hg merge --abort' to abandon
  [1]
  $ cat bar
  bleh
  $ hg st
  M bar
  M foo1