tests/test-rhg.t

merge: make mergeresult constructor initialize empty object

In future patches, we will be going to update mergeresult object
instead of building an actions dict and then setting it in the object.

Differential Revision: https://phab.mercurial-scm.org/D8819

#require rust

  $ rhg() {
  > if [ -f "$RUNTESTDIR/../rust/target/debug/rhg" ]; then
  >   "$RUNTESTDIR/../rust/target/debug/rhg" "$@"
  > else
  >   echo "skipped: Cannot find rhg. Try to run cargo build in rust/rhg."
  >   exit 80
  > fi
  > }
  $ rhg unimplemented-command
  [252]
  $ rhg root
  abort: no repository found in '$TESTTMP' (.hg not found)!
  [255]
  $ hg init repository
  $ cd repository
  $ rhg root
  $TESTTMP/repository
  $ rhg root > /dev/full
  abort: No space left on device (os error 28)
  [255]
  $ rm -rf `pwd`
  $ rhg root
  abort: error getting current working directory: $ENOENT$
  [255]