tests/test-rebase-issue-noparam-single-rev.t

discovery-helper: use reflink copy if available

A reflink copy will copy the files "as usual" but keep using the same data block
underneath. This is only supported by "copy on write" file system like btrfs or
zfs.

This will achieve similar performance that the existing hardlink clone that
Mercurial performs with the same initial space saving. However, it will behave
better on revlogs start being touch by strip. Instead of duplicating all data in
the touched revlogs, only the block actually affected by the strip will be
duplicated. This save a lot of space when building many variants of large
repositories.

The --reflink=always flag make sure the `cp` call fails if reflink copies are
not supported. Falling back to local clone.

  $ cat >> $HGRCPATH <<EOF
  > [extensions]
  > rebase=
  > 
  > [phases]
  > publish=False
  > 
  > [alias]
  > tglog = log -G --template "{rev}: {node|short} '{desc}' {branches}\n"
  > EOF


  $ hg init a
  $ cd a

  $ echo c1 > c1
  $ hg ci -Am c1
  adding c1

  $ echo c2 > c2
  $ hg ci -Am c2
  adding c2

  $ echo l1 > l1
  $ hg ci -Am l1
  adding l1

  $ hg up -q -C 1

  $ echo r1 > r1
  $ hg ci -Am r1
  adding r1
  created new head

  $ echo r2 > r2
  $ hg ci -Am r2
  adding r2

  $ hg tglog
  @  4: 225af64d03e6 'r2'
  |
  o  3: 8d0a8c99b309 'r1'
  |
  | o  2: 87c180a611f2 'l1'
  |/
  o  1: 56daeba07f4b 'c2'
  |
  o  0: e8faad3d03ff 'c1'
  
Rebase with no arguments - single revision in source branch:

  $ hg up -q -C 2

  $ hg rebase
  rebasing 2:87c180a611f2 "l1"
  saved backup bundle to $TESTTMP/a/.hg/strip-backup/87c180a611f2-a5be192d-rebase.hg

  $ hg tglog
  @  4: b1152cc99655 'l1'
  |
  o  3: 225af64d03e6 'r2'
  |
  o  2: 8d0a8c99b309 'r1'
  |
  o  1: 56daeba07f4b 'c2'
  |
  o  0: e8faad3d03ff 'c1'
  
  $ cd ..


  $ hg init b
  $ cd b

  $ echo c1 > c1
  $ hg ci -Am c1
  adding c1

  $ echo c2 > c2
  $ hg ci -Am c2
  adding c2

  $ echo l1 > l1
  $ hg ci -Am l1
  adding l1

  $ echo l2 > l2
  $ hg ci -Am l2
  adding l2

  $ hg up -q -C 1

  $ echo r1 > r1
  $ hg ci -Am r1
  adding r1
  created new head

  $ hg tglog
  @  4: 8d0a8c99b309 'r1'
  |
  | o  3: 1ac923b736ef 'l2'
  | |
  | o  2: 87c180a611f2 'l1'
  |/
  o  1: 56daeba07f4b 'c2'
  |
  o  0: e8faad3d03ff 'c1'
  
Rebase with no arguments - single revision in target branch:

  $ hg up -q -C 3

  $ hg rebase
  rebasing 2:87c180a611f2 "l1"
  rebasing 3:1ac923b736ef "l2"
  saved backup bundle to $TESTTMP/b/.hg/strip-backup/87c180a611f2-b980535c-rebase.hg

  $ hg tglog
  @  4: 023181307ed0 'l2'
  |
  o  3: 913ab52b43b4 'l1'
  |
  o  2: 8d0a8c99b309 'r1'
  |
  o  1: 56daeba07f4b 'c2'
  |
  o  0: e8faad3d03ff 'c1'
  

  $ cd ..