tests/test-rebase-legacy.t

rhg: desambiguate status without decompressing filelog if possible

When status is unsure based on `stat()` and the dirstate if a file is clean
or modified, we need to compare it against the filelog.

This comparison can skip looking at contents if the lengths differ.
This changeset optimize this further to deduce what we can about the length
if the filelog without decompressing it or resolving deltas.

Differential Revision: https://phab.mercurial-scm.org/D11965

#testcases continuecommand continueflag
Test rebase --continue with rebasestate written by legacy client

  $ cat >> $HGRCPATH <<EOF
  > [extensions]
  > rebase=
  > drawdag=$TESTDIR/drawdag.py
  > EOF

#if continueflag
  $ cat >> $HGRCPATH <<EOF
  > [alias]
  > continue = rebase --continue
  > EOF
#endif

  $ hg init
  $ hg debugdrawdag <<'EOF'
  >    D H
  >    | |
  >    C G
  >    | |
  >    B F
  >    | |
  >  Z A E
  >   \|/
  >    R
  > EOF
  $ for r in A B C D E F G H R Z
  > do
  >   eval node_$r=$(hg log -r $r -T '{node}')
  > done

rebasestate generated by a legacy client running "hg rebase -r B+D+E+G+H -d Z"

  $ touch .hg/last-message.txt
  $ cat > .hg/rebasestate <<EOF
  > 0000000000000000000000000000000000000000
  > $node_Z
  > 0000000000000000000000000000000000000000
  > 0
  > 0
  > 0
  > 
  > $node_A:-2
  > $node_E:0000000000000000000000000000000000000000
  > $node_B:0000000000000000000000000000000000000000
  > $node_F:-3
  > $node_C:-3
  > $node_G:0000000000000000000000000000000000000000
  > $node_D:0000000000000000000000000000000000000000
  > $node_H:0000000000000000000000000000000000000000
  > EOF

#if continuecommand
  $ hg continue --dry-run
  rebase in progress, will be resumed
#endif

  $ hg continue
  rebasing 4:c1e6b162678d B "B"
  rebasing 8:6f7a236de685 D "D"
  rebasing 2:de008c61a447 E "E"
  rebasing 7:d2fa1c02b240 G "G"
  rebasing 9:6582e6951a9c H tip "H"
  warning: orphaned descendants detected, not stripping c1e6b162678d, de008c61a447
  saved backup bundle to $TESTTMP/.hg/strip-backup/6f7a236de685-9880a3dc-rebase.hg

  $ hg log -G -T '{rev}:{node|short} {desc}\n'
  o  11:721b8da0a708 H
  |
  o  10:9d65695ec3c2 G
  |
  o  9:21c8397a5d68 E
  |
  | o  8:fc52970345e8 D
  | |
  | o  7:eac96551b107 B
  |/
  | o  6:bd5548558fcf C
  | |
  | | o  5:aeba276fcb7d F
  | | |
  | o |  4:c1e6b162678d B
  | | |
  o | |  3:f424eb6a8c01 Z
  | | |
  +---o  2:de008c61a447 E
  | |
  | o  1:21a6c4502885 A
  |/
  o  0:b41ce7760717 R