tests/test-username-newline.t

extdiff: escape path for docstring (issue5301)

The existing code (a) assumed path would be specified in
encoding.encoding and (b) assumed unicode() objects wouldn't cause
other parts of Mercurial to blow up. Both are dangerous assumptions.

Since we don't know the encoding of path and can't pass non-ASCII
through docstrings, just escape the path and drop the early _(). Will
have to suffice until we can teach docstrings to handle UTF-8b
escaping.

This has the side-effect that the line containing the path is now
variable by the time it reaches _() and thus can't be translated.

  $ hg init
  $ touch a

  $ unset HGUSER
  $ echo "[ui]" >> .hg/hgrc
  $ echo "username= foo" >> .hg/hgrc
  $ echo "          bar1" >> .hg/hgrc

  $ hg ci -Am m
  adding a
  abort: username 'foo\nbar1' contains a newline
  
  [255]
  $ rm .hg/hgrc

  $ HGUSER=`(echo foo; echo bar2)` hg ci -Am m
  abort: username 'foo\nbar2' contains a newline
  
  [255]
  $ hg ci -Am m -u "`(echo foo; echo bar3)`"
  transaction abort!
  rollback completed
  abort: username 'foo\nbar3' contains a newline!
  [255]