tests/test-merge-types.t

check-code: catch Python 'is' comparing number or string literals

The Python 'is' operator compares object identity, so it should
definitely not be applied to string or number literals, which Python
implementations are free to represent with a temporary object.

This should catch the following kinds of bogus expressions (examples):

  x is 'foo'     x is not 'foo'
  x is "bar"     x is not "bar"
  x is 42        x is not 42
  x is -36       x is not -36

As originally proposed by Martin Geisler, amended with catching
negative numbers.

  $ hg init

  $ echo a > a
  $ hg ci -Amadd
  adding a

  $ chmod +x a
  $ hg ci -mexecutable

  $ hg up 0
  0 files updated, 0 files merged, 0 files removed, 0 files unresolved
  $ rm a
  $ ln -s symlink a
  $ hg ci -msymlink
  created new head

  $ hg merge --debug
    searching for copies back to rev 1
  resolving manifests
   overwrite None partial False
   ancestor c334dc3be0da local 521a1e40188f+ remote 3574f3e69b1c
   conflicting flags for a
  (n)one, e(x)ec or sym(l)ink? n
   a: update permissions -> e
  updating: a 1/1 files (100.00%)
  0 files updated, 0 files merged, 0 files removed, 0 files unresolved
  (branch merge, don't forget to commit)


Symlink is local parent, executable is other:

  $ if [ -h a ]; then
  >     echo a is a symlink
  >     $TESTDIR/readlink.py a
  > elif [ -x a ]; then
  >     echo a is executable
  > else
  >     echo "a has no flags (default for conflicts)"
  > fi
  a has no flags (default for conflicts)

  $ hg update -C 1
  1 files updated, 0 files merged, 0 files removed, 0 files unresolved

  $ hg merge --debug
    searching for copies back to rev 1
  resolving manifests
   overwrite None partial False
   ancestor c334dc3be0da local 3574f3e69b1c+ remote 521a1e40188f
   conflicting flags for a
  (n)one, e(x)ec or sym(l)ink? n
   a: remote is newer -> g
  updating: a 1/1 files (100.00%)
  getting a
  1 files updated, 0 files merged, 0 files removed, 0 files unresolved
  (branch merge, don't forget to commit)


Symlink is other parent, executable is local:

  $ if [ -h a ]; then
  >    echo a is a symlink
  >    $TESTDIR/readlink.py a
  > elif [ -x a ]; then
  >     echo a is executable
  > else
  >     echo "a has no flags (default for conflicts)"
  > fi
  a has no flags (default for conflicts)