tests/testlib/merge-combination-util.sh

dirstate-item: make sure we load `mtime-second-ambiguous` from disk

Now that we support the associated logic, we can safely load it from it. It is
no longer necessary to ignore the stored mtime when the flag is encountered.

Differential Revision: https://phab.mercurial-scm.org/D11846

# genmerges is the workhorse of the test-merge-combination-*.t tests.

# Given:
# - a `range` function describing the possible values for file a
# - a `isgood` function to filter out uninteresting combination
# - a `createfile` function to actually write the values for file a on the
#   filesystem
#
# it print a series of lines that look like: abcd C: output of -T {files}
# describing the file a at respectively the base, p2, p1, merge
# revision. "C" indicates that hg merge had conflicts.

genmerges () {

  (LC_ALL=C type range | grep -q 'function') || (echo >&2 "missing function: range")
  (LC_ALL=C type isgood | grep -q 'function') || (echo >&2 "missing function: isgood")
  (LC_ALL=C type createfile | grep -q 'function') || (echo >&2 "missing function: createfile")

  for base in `range` -; do
    for r1 in `range $base` -; do
      for r2 in `range $base $r1` -; do
        for m in `range $base $r1 $r2` -; do
          line="$base$r1$r2$m"
          isgood $line || continue
          hg init repo
          cd repo
          make_commit () {
            v=$1; msg=$2; file=$3;
            if [ $v != - ]; then
              createfile $v
            else
              if [ -f a ]
              then rm a
              else touch $file
              fi
            fi
            hg commit -q -Am $msg || exit 123
          }
          echo foo > foo
          make_commit $base base b
          make_commit $r1 r1 c
          hg up -r 0 -q
          make_commit $r2 r2 d
          hg merge -q -r 1 > ../output 2>&1
          if [ $? -ne 0 ]; then rm -f *.orig; hg resolve -m --all -q; fi
          if [ -s ../output ]; then conflicts=" C"; else conflicts="  "; fi
          make_commit $m m e
          if [ $m = $r1 ] && [ $m = $r2 ]
          then expected=
          elif [ $m = $r1 ]
          then if [ $base = $r2 ]
               then expected=
               else expected=a
               fi
          elif [ $m = $r2 ]
          then if [ $base = $r1 ]
               then expected=
               else expected=a
               fi
          else expected=a
          fi
          got=`hg log -r 3 --template '{files}\n' | tr -d 'e '`
          if [ "$got" = "$expected" ]
          then echo "$line$conflicts: agree on \"$got\""
          else echo "$line$conflicts: hg said \"$got\", expected \"$expected\""
          fi
          cd ../
          rm -rf repo
        done
      done
    done
  done
}