tests/test-bdiff.py.out

dispatch: move part of callcatch to scmutil

Per discussion at 39149b6036e6 [1], we need "callcatch" in worker.py. Move
it to scmutil.py to avoid cycles.

Note that dispatch's callcatch handles some additional high-level exceptions
related to config parsing, and commands. Moving them to scmutil will make
scmutil depend on "commands" or require "_formatparse" and "_getsimilar"
(and "difflib") to be moved as well. In the worker use-case, it is forked
when config and commands are fully loaded. So it should not care about those
exceptions.

[1]: https://www.mercurial-scm.org/pipermail/mercurial-devel/2016-August/087116.html

test 'a\nc\n\n\n\n' 'a\nb\n\n\n'
test 'a\nb\nc\n' 'a\nc\n'
test '' ''
test 'a\nb\nc' 'a\nb\nc'
test 'a\nb\nc\nd\n' 'a\nd\n'
test 'a\nb\nc\nd\n' 'a\nc\ne\n'
test 'a\nb\nc\n' 'a\nc\n'
test 'a\n' 'c\na\nb\n'
test 'a\n' ''
test 'a\n' 'b\nc\n'
test 'a\n' 'c\na\n'
test '' 'adjfkjdjksdhfksj'
test '' 'ab'
test '' 'abc'
test 'a' 'a'
test 'ab' 'ab'
test 'abc' 'abc'
test 'a\n' 'a\n'
test 'a\nb' 'a\nb'
showdiff(
  'x\n\nx\n\nx\n\nx\n\nz\n',
  'x\n\nx\n\ny\n\nx\n\nx\n\nz\n'):
 'x\n\nx\n\n'
 6 6 '' -> 'y\n\n'
 'x\n\nx\n\nz\n'
showdiff(
  'x\n\nx\n\nx\n\nx\n\nz\n',
  'x\n\nx\n\ny\n\nx\n\ny\n\nx\n\nz\n'):
 'x\n\nx\n\n'
 6 6 '' -> 'y\n\n'
 'x\n\n'
 9 9 '' -> 'y\n\n'
 'x\n\nz\n'
showdiff(
  'a\nb\nb\nb\nc\n.\nd\ne\n.\nf\n',
  'a\nb\nb\na\nb\nb\nb\nc\n.\nb\nc\n.\nd\ne\nf\n'):
 0 0 '' -> 'a\nb\nb\n'
 'a\nb\nb\nb\nc\n.\n'
 12 12 '' -> 'b\nc\n.\n'
 'd\ne\n'
 16 18 '.\n' -> ''
 'f\n'
done
done
Nice diff for a trivial change:
showdiff(
  '<0\n-\n<1\n-\n<2\n-\n<3\n-\n<4\n-\n',
  '>0\n-\n>1\n-\n>2\n-\n>3\n-\n>4\n-\n'):
 0 3 '<0\n' -> '>0\n'
 '-\n'
 5 8 '<1\n' -> '>1\n'
 '-\n'
 10 13 '<2\n' -> '>2\n'
 '-\n'
 15 18 '<3\n' -> '>3\n'
 '-\n'
 20 23 '<4\n' -> '>4\n'
 '-\n'
Diff 1 to 3 lines - preference for appending:
showdiff(
  'a\n',
  'a\na\na\n'):
 'a\n'
 2 2 '' -> 'a\na\n'
Diff 1 to 5 lines - preference for appending:
showdiff(
  'a\n',
  'a\na\na\na\na\n'):
 'a\n'
 2 2 '' -> 'a\na\na\na\n'
Diff 3 to 1 lines - preference for removing trailing lines:
showdiff(
  'a\na\na\n',
  'a\n'):
 'a\n'
 2 6 'a\na\n' -> ''
Diff 5 to 1 lines - preference for removing trailing lines:
showdiff(
  'a\na\na\na\na\n',
  'a\n'):
 'a\n'
 2 10 'a\na\na\na\n' -> ''