view tests/test-rebase-inmemory.t @ 44118:f81c17ec303c

hgdemandimport: apply lazy module loading to sys.meta_path finders

Python's `sys.meta_path` finders are the primary objects whose job it
is to find a module at import time. When `import` is called, Python
iterates objects in this list and calls `o.find_spec(...)` to find
a `ModuleSpec` (or None if the module couldn't be found by that
finder). If no meta path finder can find a module, import fails.

One of the default meta path finders is `PathFinder`. Its job is to
import modules from the filesystem and is probably the most important
importer. This finder looks at `sys.path` and `sys.path_hooks` to do
its job.

The `ModuleSpec` returned by `MetaPathImporter.find_spec()` has a
`loader` attribute, which defines the concrete module loader to use.
`sys.path_hooks` is a hook point for teaching `PathFinder` to
instantiate custom loader types.

Previously, we injected a custom `sys.path_hook` that told `PathFinder`
to wrap the default loaders with a loader that creates a module object
that is lazy.

This approach worked. But its main limitation was that it only applied
to the `PathFinder` meta path importer. There are other meta path
importers that are registered. And in the case of PyOxidizer loading
modules from memory, `PathFinder` doesn't come into play since
PyOxidizer's own meta path importer was handling all imports.

This commit changes our approach to lazy module loading by proxying
all meta path importers. Specifically, we overload the `find_spec()`
method to swap in a wrapped loader on the `ModuleSpec` before it
is returned. The end result of this is all meta path importers should
be lazy.

As much as I would have loved to utilize .__class__ manipulation to
achieve this, some meta path importers are implemented in C/Rust
in such a way that they cannot be monkeypatched. This is why we
use __getattribute__ to define a proxy.

Also, this change could theoretically open us up to regressions in
meta path importers whose loader is creating module objects which
can't be monkeypatched. But I'm not aware of any of these in the
wild. So I think we'll be safe.

According to hyperfine, this change yields a decent startup time win of
5-6ms:

```
Benchmark #1: ~/.pyenv/versions/3.6.10/bin/python ./hg version
  Time (mean ± σ):      86.8 ms ±   0.5 ms    [User: 78.0 ms, System: 8.7 ms]
  Range (min … max):    86.0 ms …  89.1 ms    50 runs

  Time (mean ± σ):      81.1 ms ±   2.7 ms    [User: 74.5 ms, System: 6.5 ms]
  Range (min … max):    77.8 ms …  90.5 ms    50 runs

Benchmark #2: ~/.pyenv/versions/3.7.6/bin/python ./hg version
  Time (mean ± σ):      78.9 ms ±   0.6 ms    [User: 70.2 ms, System: 8.7 ms]
  Range (min … max):    78.1 ms …  81.2 ms    50 runs

  Time (mean ± σ):      73.4 ms ±   0.6 ms    [User: 65.3 ms, System: 8.0 ms]
  Range (min … max):    72.4 ms …  75.7 ms    50 runs

Benchmark #3: ~/.pyenv/versions/3.8.1/bin/python ./hg version
  Time (mean ± σ):      78.1 ms ±   0.6 ms    [User: 70.2 ms, System: 7.9 ms]
  Range (min … max):    77.4 ms …  80.9 ms    50 runs

  Time (mean ± σ):      72.1 ms ±   0.4 ms    [User: 64.4 ms, System: 7.6 ms]
  Range (min … max):    71.4 ms …  74.1 ms    50 runs
```

Differential Revision: https://phab.mercurial-scm.org/D7954

#require symlink execbit
  $ cat << EOF >> $HGRCPATH
  > [phases]
  > publish=False
  > [extensions]
  > amend=
  > rebase=
  > debugdrawdag=$TESTDIR/drawdag.py
  > strip=
  > [rebase]
  > experimental.inmemory=1
  > [diff]
  > git=1
  > [alias]
  > tglog = log -G --template "{rev}: {node|short} '{desc}'\n"
  > EOF

Rebase a simple DAG:
  $ hg init repo1
  $ cd repo1
  $ hg debugdrawdag <<'EOS'
  > c b
  > |/
  > d
  > |
  > a
  > EOS
  $ hg up -C a
  1 files updated, 0 files merged, 0 files removed, 0 files unresolved
  $ hg tglog
  o  3: 814f6bd05178 'c'
  |
  | o  2: db0e82a16a62 'b'
  |/
  o  1: 02952614a83d 'd'
  |
  @  0: b173517d0057 'a'
  
  $ hg cat -r 3 c
  c (no-eol)
  $ hg cat -r 2 b
  b (no-eol)
  $ hg rebase --debug -r b -d c | grep rebasing
  rebasing in-memory
  rebasing 2:db0e82a16a62 "b" (b)
  $ hg tglog
  o  3: ca58782ad1e4 'b'
  |
  o  2: 814f6bd05178 'c'
  |
  o  1: 02952614a83d 'd'
  |
  @  0: b173517d0057 'a'
  
  $ hg cat -r 3 b
  b (no-eol)
  $ hg cat -r 2 c
  c (no-eol)
  $ cd ..

Case 2:
  $ hg init repo2
  $ cd repo2
  $ hg debugdrawdag <<'EOS'
  > c b
  > |/
  > d
  > |
  > a
  > EOS

Add a symlink and executable file:
  $ hg up -C c
  3 files updated, 0 files merged, 0 files removed, 0 files unresolved
  $ ln -s somefile e
  $ echo f > f
  $ chmod +x f
  $ hg add e f
  $ hg amend -q
  $ hg up -Cq a

Write files to the working copy, and ensure they're still there after the rebase
  $ echo "abc" > a
  $ ln -s def b
  $ echo "ghi" > c
  $ echo "jkl" > d
  $ echo "mno" > e
  $ hg tglog
  o  3: f56b71190a8f 'c'
  |
  | o  2: db0e82a16a62 'b'
  |/
  o  1: 02952614a83d 'd'
  |
  @  0: b173517d0057 'a'
  
  $ hg cat -r 3 c
  c (no-eol)
  $ hg cat -r 2 b
  b (no-eol)
  $ hg cat -r 3 e
  somefile (no-eol)
  $ hg rebase --debug -s b -d a | grep rebasing
  rebasing in-memory
  rebasing 2:db0e82a16a62 "b" (b)
  $ hg tglog
  o  3: fc055c3b4d33 'b'
  |
  | o  2: f56b71190a8f 'c'
  | |
  | o  1: 02952614a83d 'd'
  |/
  @  0: b173517d0057 'a'
  
  $ hg cat -r 2 c
  c (no-eol)
  $ hg cat -r 3 b
  b (no-eol)
  $ hg rebase --debug -s 1 -d 3 | grep rebasing
  rebasing in-memory
  rebasing 1:02952614a83d "d" (d)
  rebasing 2:f56b71190a8f "c"
  $ hg tglog
  o  3: 753feb6fd12a 'c'
  |
  o  2: 09c044d2cb43 'd'
  |
  o  1: fc055c3b4d33 'b'
  |
  @  0: b173517d0057 'a'
  
Ensure working copy files are still there:
  $ cat a
  abc
  $ readlink.py b
  b -> def
  $ cat e
  mno

Ensure symlink and executable files were rebased properly:
  $ hg up -Cq 3
  $ readlink.py e
  e -> somefile
  $ ls -l f | cut -c -10
  -rwxr-xr-x

Rebase the working copy parent
  $ hg up -C 3
  0 files updated, 0 files merged, 0 files removed, 0 files unresolved
  $ hg rebase -r 3 -d 0 --debug | grep rebasing
  rebasing in-memory
  rebasing 3:753feb6fd12a "c" (tip)
  $ hg tglog
  @  3: 844a7de3e617 'c'
  |
  | o  2: 09c044d2cb43 'd'
  | |
  | o  1: fc055c3b4d33 'b'
  |/
  o  0: b173517d0057 'a'
  

Test reporting of path conflicts

  $ hg rm a
  $ mkdir a
  $ touch a/a
  $ hg ci -Am "a/a"
  adding a/a
  $ hg tglog
  @  4: daf7dfc139cb 'a/a'
  |
  o  3: 844a7de3e617 'c'
  |
  | o  2: 09c044d2cb43 'd'
  | |
  | o  1: fc055c3b4d33 'b'
  |/
  o  0: b173517d0057 'a'
  
  $ hg rebase -r . -d 2
  rebasing 4:daf7dfc139cb "a/a" (tip)
  saved backup bundle to $TESTTMP/repo2/.hg/strip-backup/daf7dfc139cb-fdbfcf4f-rebase.hg

  $ hg tglog
  @  4: c6ad37a4f250 'a/a'
  |
  | o  3: 844a7de3e617 'c'
  | |
  o |  2: 09c044d2cb43 'd'
  | |
  o |  1: fc055c3b4d33 'b'
  |/
  o  0: b173517d0057 'a'
  
  $ echo foo > foo
  $ hg ci -Aqm "added foo"
  $ hg up '.^'
  0 files updated, 0 files merged, 1 files removed, 0 files unresolved
  $ echo bar > bar
  $ hg ci -Aqm "added bar"
  $ hg rm a/a
  $ echo a > a
  $ hg ci -Aqm "added a back!"
  $ hg tglog
  @  7: 855e9797387e 'added a back!'
  |
  o  6: d14530e5e3e6 'added bar'
  |
  | o  5: 9b94b9373deb 'added foo'
  |/
  o  4: c6ad37a4f250 'a/a'
  |
  | o  3: 844a7de3e617 'c'
  | |
  o |  2: 09c044d2cb43 'd'
  | |
  o |  1: fc055c3b4d33 'b'
  |/
  o  0: b173517d0057 'a'
  
  $ hg rebase -r . -d 5
  rebasing 7:855e9797387e "added a back!" (tip)
  saved backup bundle to $TESTTMP/repo2/.hg/strip-backup/855e9797387e-81ee4c5d-rebase.hg

  $ hg tglog
  @  7: bb3f02be2688 'added a back!'
  |
  | o  6: d14530e5e3e6 'added bar'
  | |
  o |  5: 9b94b9373deb 'added foo'
  |/
  o  4: c6ad37a4f250 'a/a'
  |
  | o  3: 844a7de3e617 'c'
  | |
  o |  2: 09c044d2cb43 'd'
  | |
  o |  1: fc055c3b4d33 'b'
  |/
  o  0: b173517d0057 'a'
  
  $ mkdir -p c/subdir
  $ echo c > c/subdir/file.txt
  $ hg add c/subdir/file.txt
  $ hg ci -m 'c/subdir/file.txt'
  $ hg rebase -r . -d 3 -n
  starting dry-run rebase; repository will not be changed
  rebasing 8:e147e6e3c490 "c/subdir/file.txt" (tip)
  abort: error: 'c/subdir/file.txt' conflicts with file 'c' in 3.
  [255]
FIXME: shouldn't need this, but when we hit path conflicts in dryrun mode, we
don't clean up rebasestate.
  $ hg rebase --abort
  rebase aborted
  $ hg rebase -r 3 -d . -n
  starting dry-run rebase; repository will not be changed
  rebasing 3:844a7de3e617 "c"
  abort: error: file 'c' cannot be written because  'c/' is a directory in e147e6e3c490 (containing 1 entries: c/subdir/file.txt)
  [255]

  $ cd ..

Test path auditing (issue5818)

  $ mkdir lib_
  $ ln -s lib_ lib
  $ hg init repo
  $ cd repo
  $ mkdir -p ".$TESTTMP/lib"
  $ touch ".$TESTTMP/lib/a"
  $ hg add ".$TESTTMP/lib/a"
  $ hg ci -m 'a'

  $ touch ".$TESTTMP/lib/b"
  $ hg add ".$TESTTMP/lib/b"
  $ hg ci -m 'b'

  $ hg up -q '.^'
  $ touch ".$TESTTMP/lib/c"
  $ hg add ".$TESTTMP/lib/c"
  $ hg ci -m 'c'
  created new head
  $ hg rebase -s 1 -d .
  rebasing 1:* "b" (glob)
  saved backup bundle to $TESTTMP/repo/.hg/strip-backup/*-rebase.hg (glob)
  $ cd ..

Test dry-run rebasing

  $ hg init repo3
  $ cd repo3
  $ echo a>a
  $ hg ci -Aqma
  $ echo b>b
  $ hg ci -Aqmb
  $ echo c>c
  $ hg ci -Aqmc
  $ echo d>d
  $ hg ci -Aqmd
  $ echo e>e
  $ hg ci -Aqme

  $ hg up 1 -q
  $ echo f>f
  $ hg ci -Amf
  adding f
  created new head
  $ echo g>g
  $ hg ci -Aqmg
  $ hg log -G --template "{rev}:{short(node)} {person(author)}\n{firstline(desc)} {topic}\n\n"
  @  6:baf10c5166d4 test
  |  g
  |
  o  5:6343ca3eff20 test
  |  f
  |
  | o  4:e860deea161a test
  | |  e
  | |
  | o  3:055a42cdd887 test
  | |  d
  | |
  | o  2:177f92b77385 test
  |/   c
  |
  o  1:d2ae7f538514 test
  |  b
  |
  o  0:cb9a9f314b8b test
     a
  
Make sure it throws error while passing --continue or --abort with --dry-run
  $ hg rebase -s 2 -d 6 -n --continue
  abort: cannot specify both --continue and --dry-run
  [255]
  $ hg rebase -s 2 -d 6 -n --abort
  abort: cannot specify both --abort and --dry-run
  [255]

Check dryrun gives correct results when there is no conflict in rebasing
  $ hg rebase -s 2 -d 6 -n
  starting dry-run rebase; repository will not be changed
  rebasing 2:177f92b77385 "c"
  rebasing 3:055a42cdd887 "d"
  rebasing 4:e860deea161a "e"
  dry-run rebase completed successfully; run without -n/--dry-run to perform this rebase

  $ hg diff
  $ hg status

  $ hg log -G --template "{rev}:{short(node)} {person(author)}\n{firstline(desc)} {topic}\n\n"
  @  6:baf10c5166d4 test
  |  g
  |
  o  5:6343ca3eff20 test
  |  f
  |
  | o  4:e860deea161a test
  | |  e
  | |
  | o  3:055a42cdd887 test
  | |  d
  | |
  | o  2:177f92b77385 test
  |/   c
  |
  o  1:d2ae7f538514 test
  |  b
  |
  o  0:cb9a9f314b8b test
     a
  
Check dryrun working with --collapse when there is no conflict
  $ hg rebase -s 2 -d 6 -n --collapse
  starting dry-run rebase; repository will not be changed
  rebasing 2:177f92b77385 "c"
  rebasing 3:055a42cdd887 "d"
  rebasing 4:e860deea161a "e"
  dry-run rebase completed successfully; run without -n/--dry-run to perform this rebase

Check dryrun gives correct results when there is conflict in rebasing
Make a conflict:
  $ hg up 6 -q
  $ echo conflict>e
  $ hg ci -Aqm "conflict with e"
  $ hg log -G --template "{rev}:{short(node)} {person(author)}\n{firstline(desc)} {topic}\n\n"
  @  7:d2c195b28050 test
  |  conflict with e
  |
  o  6:baf10c5166d4 test
  |  g
  |
  o  5:6343ca3eff20 test
  |  f
  |
  | o  4:e860deea161a test
  | |  e
  | |
  | o  3:055a42cdd887 test
  | |  d
  | |
  | o  2:177f92b77385 test
  |/   c
  |
  o  1:d2ae7f538514 test
  |  b
  |
  o  0:cb9a9f314b8b test
     a
  
  $ hg rebase -s 2 -d 7 -n
  starting dry-run rebase; repository will not be changed
  rebasing 2:177f92b77385 "c"
  rebasing 3:055a42cdd887 "d"
  rebasing 4:e860deea161a "e"
  merging e
  transaction abort!
  rollback completed
  hit a merge conflict
  [1]
  $ hg diff
  $ hg status
  $ hg log -G --template "{rev}:{short(node)} {person(author)}\n{firstline(desc)} {topic}\n\n"
  @  7:d2c195b28050 test
  |  conflict with e
  |
  o  6:baf10c5166d4 test
  |  g
  |
  o  5:6343ca3eff20 test
  |  f
  |
  | o  4:e860deea161a test
  | |  e
  | |
  | o  3:055a42cdd887 test
  | |  d
  | |
  | o  2:177f92b77385 test
  |/   c
  |
  o  1:d2ae7f538514 test
  |  b
  |
  o  0:cb9a9f314b8b test
     a
  
Check dryrun working with --collapse when there is conflicts
  $ hg rebase -s 2 -d 7 -n --collapse
  starting dry-run rebase; repository will not be changed
  rebasing 2:177f92b77385 "c"
  rebasing 3:055a42cdd887 "d"
  rebasing 4:e860deea161a "e"
  merging e
  hit a merge conflict
  [1]

In-memory rebase that fails due to merge conflicts

  $ hg rebase -s 2 -d 7
  rebasing 2:177f92b77385 "c"
  rebasing 3:055a42cdd887 "d"
  rebasing 4:e860deea161a "e"
  merging e
  transaction abort!
  rollback completed
  hit merge conflicts; re-running rebase without in-memory merge
  rebasing 2:177f92b77385 "c"
  rebasing 3:055a42cdd887 "d"
  rebasing 4:e860deea161a "e"
  merging e
  warning: conflicts while merging e! (edit, then use 'hg resolve --mark')
  unresolved conflicts (see hg resolve, then hg rebase --continue)
  [1]
  $ hg rebase --abort
  saved backup bundle to $TESTTMP/repo3/.hg/strip-backup/c1e524d4287c-f91f82e1-backup.hg
  rebase aborted

Retrying without in-memory merge won't lose working copy changes
  $ cd ..
  $ hg clone repo3 repo3-dirty -q
  $ cd repo3-dirty
  $ echo dirty > a
  $ hg rebase -s 2 -d 7
  rebasing 2:177f92b77385 "c"
  rebasing 3:055a42cdd887 "d"
  rebasing 4:e860deea161a "e"
  merging e
  transaction abort!
  rollback completed
  hit merge conflicts; re-running rebase without in-memory merge
  abort: uncommitted changes
  [255]
  $ cat a
  dirty

Retrying without in-memory merge won't lose merge state
  $ cd ..
  $ hg clone repo3 repo3-merge-state -q
  $ cd repo3-merge-state
  $ hg merge 4
  merging e
  warning: conflicts while merging e! (edit, then use 'hg resolve --mark')
  2 files updated, 0 files merged, 0 files removed, 1 files unresolved
  use 'hg resolve' to retry unresolved file merges or 'hg merge --abort' to abandon
  [1]
  $ hg resolve -l
  U e
  $ hg rebase -s 2 -d 7
  abort: outstanding uncommitted merge
  (use 'hg commit' or 'hg merge --abort')
  [255]
  $ hg resolve -l
  U e

==========================
Test for --confirm option|
==========================
  $ cd ..
  $ hg clone repo3 repo4 -q
  $ cd repo4
  $ hg strip 7 -q
  $ hg log -G --template "{rev}:{short(node)} {person(author)}\n{firstline(desc)} {topic}\n\n"
  @  6:baf10c5166d4 test
  |  g
  |
  o  5:6343ca3eff20 test
  |  f
  |
  | o  4:e860deea161a test
  | |  e
  | |
  | o  3:055a42cdd887 test
  | |  d
  | |
  | o  2:177f92b77385 test
  |/   c
  |
  o  1:d2ae7f538514 test
  |  b
  |
  o  0:cb9a9f314b8b test
     a
  
Check it gives error when both --dryrun and --confirm is used:
  $ hg rebase -s 2 -d . --confirm --dry-run
  abort: cannot specify both --confirm and --dry-run
  [255]
  $ hg rebase -s 2 -d . --confirm --abort
  abort: cannot specify both --abort and --confirm
  [255]
  $ hg rebase -s 2 -d . --confirm --continue
  abort: cannot specify both --continue and --confirm
  [255]

Test --confirm option when there are no conflicts:
  $ hg rebase -s 2 -d . --keep --config ui.interactive=True --confirm << EOF
  > n
  > EOF
  starting in-memory rebase
  rebasing 2:177f92b77385 "c"
  rebasing 3:055a42cdd887 "d"
  rebasing 4:e860deea161a "e"
  rebase completed successfully
  apply changes (yn)? n
  $ hg log -G --template "{rev}:{short(node)} {person(author)}\n{firstline(desc)} {topic}\n\n"
  @  6:baf10c5166d4 test
  |  g
  |
  o  5:6343ca3eff20 test
  |  f
  |
  | o  4:e860deea161a test
  | |  e
  | |
  | o  3:055a42cdd887 test
  | |  d
  | |
  | o  2:177f92b77385 test
  |/   c
  |
  o  1:d2ae7f538514 test
  |  b
  |
  o  0:cb9a9f314b8b test
     a
  
  $ hg rebase -s 2 -d . --keep --config ui.interactive=True --confirm << EOF
  > y
  > EOF
  starting in-memory rebase
  rebasing 2:177f92b77385 "c"
  rebasing 3:055a42cdd887 "d"
  rebasing 4:e860deea161a "e"
  rebase completed successfully
  apply changes (yn)? y
  $ hg log -G --template "{rev}:{short(node)} {person(author)}\n{firstline(desc)} {topic}\n\n"
  o  9:9fd28f55f6dc test
  |  e
  |
  o  8:12cbf031f469 test
  |  d
  |
  o  7:c83b1da5b1ae test
  |  c
  |
  @  6:baf10c5166d4 test
  |  g
  |
  o  5:6343ca3eff20 test
  |  f
  |
  | o  4:e860deea161a test
  | |  e
  | |
  | o  3:055a42cdd887 test
  | |  d
  | |
  | o  2:177f92b77385 test
  |/   c
  |
  o  1:d2ae7f538514 test
  |  b
  |
  o  0:cb9a9f314b8b test
     a
  
Test --confirm option when there is a conflict
  $ hg up tip -q
  $ echo ee>e
  $ hg ci --amend -m "conflict with e" -q
  $ hg log -G --template "{rev}:{short(node)} {person(author)}\n{firstline(desc)} {topic}\n\n"
  @  9:906d72f66a59 test
  |  conflict with e
  |
  o  8:12cbf031f469 test
  |  d
  |
  o  7:c83b1da5b1ae test
  |  c
  |
  o  6:baf10c5166d4 test
  |  g
  |
  o  5:6343ca3eff20 test
  |  f
  |
  | o  4:e860deea161a test
  | |  e
  | |
  | o  3:055a42cdd887 test
  | |  d
  | |
  | o  2:177f92b77385 test
  |/   c
  |
  o  1:d2ae7f538514 test
  |  b
  |
  o  0:cb9a9f314b8b test
     a
  
  $ hg rebase -s 4 -d . --keep --confirm
  starting in-memory rebase
  rebasing 4:e860deea161a "e"
  merging e
  hit a merge conflict
  [1]
  $ hg log -G --template "{rev}:{short(node)} {person(author)}\n{firstline(desc)} {topic}\n\n"
  @  9:906d72f66a59 test
  |  conflict with e
  |
  o  8:12cbf031f469 test
  |  d
  |
  o  7:c83b1da5b1ae test
  |  c
  |
  o  6:baf10c5166d4 test
  |  g
  |
  o  5:6343ca3eff20 test
  |  f
  |
  | o  4:e860deea161a test
  | |  e
  | |
  | o  3:055a42cdd887 test
  | |  d
  | |
  | o  2:177f92b77385 test
  |/   c
  |
  o  1:d2ae7f538514 test
  |  b
  |
  o  0:cb9a9f314b8b test
     a
  
Test a metadata-only in-memory merge
  $ cd $TESTTMP
  $ hg init no_exception
  $ cd no_exception
# Produce the following graph:
#   o  'add +x to foo.txt'
#   | o  r1  (adds bar.txt, just for something to rebase to)
#   |/
#   o  r0   (adds foo.txt, no +x)
  $ echo hi > foo.txt
  $ hg ci -qAm r0
  $ echo hi > bar.txt
  $ hg ci -qAm r1
  $ hg co -qr ".^"
  $ chmod +x foo.txt
  $ hg ci -qAm 'add +x to foo.txt'
issue5960: this was raising an AttributeError exception
  $ hg rebase -r . -d 1
  rebasing 2:539b93e77479 "add +x to foo.txt" (tip)
  saved backup bundle to $TESTTMP/no_exception/.hg/strip-backup/*.hg (glob)
  $ hg diff -c tip
  diff --git a/foo.txt b/foo.txt
  old mode 100644
  new mode 100755

Test rebasing a commit with copy information, but no content changes

  $ cd ..
  $ hg clone -q repo1 merge-and-rename
  $ cd merge-and-rename
  $ cat << EOF >> .hg/hgrc
  > [experimental]
  > evolution.createmarkers=True
  > evolution.allowunstable=True
  > EOF
  $ hg co -q 1
  $ hg mv d e
  $ hg ci -qm 'rename d to e'
  $ hg co -q 3
  $ hg merge -q 4
  $ hg ci -m 'merge'
  $ hg co -q 2
  $ mv d e
  $ hg addremove -qs 0
  $ hg ci -qm 'untracked rename of d to e'
  $ hg debugobsolete -q `hg log -T '{node}' -r 4` `hg log -T '{node}' -r .`
  1 new orphan changesets
  $ hg tglog
  @  6: 676538af172d 'untracked rename of d to e'
  |
  | *    5: 574d92ad16fc 'merge'
  | |\
  | | x  4: 2c8b5dad7956 'rename d to e'
  | | |
  | o |  3: ca58782ad1e4 'b'
  |/ /
  o /  2: 814f6bd05178 'c'
  |/
  o  1: 02952614a83d 'd'
  |
  o  0: b173517d0057 'a'
  
  $ hg rebase -b 5 -d tip
  rebasing 3:ca58782ad1e4 "b"
  rebasing 5:574d92ad16fc "merge"
  note: not rebasing 5:574d92ad16fc "merge", its destination already has all its changes

  $ cd ..

Test rebasing a commit with copy information

  $ hg init rebase-rename
  $ cd rebase-rename
  $ echo a > a
  $ hg ci -Aqm 'add a'
  $ echo a2 > a
  $ hg ci -m 'modify a'
  $ hg co -q 0
  $ hg mv a b
  $ hg ci -qm 'rename a to b'
  $ hg rebase -d 1
  rebasing 2:b977edf6f839 "rename a to b" (tip)
  merging a and b to b
  saved backup bundle to $TESTTMP/rebase-rename/.hg/strip-backup/b977edf6f839-0864f570-rebase.hg
  $ hg st --copies --change .
  A b
    a
  R a
  $ cd ..

Test rebasing a commit with copy information, where the target is empty

  $ hg init rebase-rename-empty
  $ cd rebase-rename-empty
  $ echo a > a
  $ hg ci -Aqm 'add a'
  $ cat > a
  $ hg ci -m 'make a empty'
  $ hg co -q 0
  $ hg mv a b
  $ hg ci -qm 'rename a to b'
  $ hg rebase -d 1
  rebasing 2:b977edf6f839 "rename a to b" (tip)
  merging a and b to b
  saved backup bundle to $TESTTMP/rebase-rename-empty/.hg/strip-backup/b977edf6f839-0864f570-rebase.hg
  $ hg st --copies --change .
  A b
    a
  R a
  $ cd ..
Rebase across a copy with --collapse

  $ hg init rebase-rename-collapse
  $ cd rebase-rename-collapse
  $ echo a > a
  $ hg ci -Aqm 'add a'
  $ hg mv a b
  $ hg ci -m 'rename a to b'
  $ hg co -q 0
  $ echo a2 > a
  $ hg ci -qm 'modify a'
  $ hg rebase -r . -d 1 --collapse
  rebasing 2:41c4ea50d4cf "modify a" (tip)
  merging b and a to b
  saved backup bundle to $TESTTMP/rebase-rename-collapse/.hg/strip-backup/41c4ea50d4cf-b90b7994-rebase.hg
  $ cd ..

Test rebasing when the file we are merging in destination is empty

  $ hg init test
  $ cd test
  $ echo a > foo
  $ hg ci -Aqm 'added a to foo'

  $ rm foo
  $ touch foo
  $ hg di
  diff --git a/foo b/foo
  --- a/foo
  +++ b/foo
  @@ -1,1 +0,0 @@
  -a

  $ hg ci -m "make foo an empty file"

  $ hg up '.^'
  1 files updated, 0 files merged, 0 files removed, 0 files unresolved
  $ echo b > foo
  $ hg di
  diff --git a/foo b/foo
  --- a/foo
  +++ b/foo
  @@ -1,1 +1,1 @@
  -a
  +b
  $ hg ci -m "add b to foo"
  created new head

  $ hg rebase -r . -d 1 --config ui.merge=internal:merge3
  rebasing 2:fb62b706688e "add b to foo" (tip)
  merging foo
  hit merge conflicts; re-running rebase without in-memory merge
  rebasing 2:fb62b706688e "add b to foo" (tip)
  merging foo
  warning: conflicts while merging foo! (edit, then use 'hg resolve --mark')
  unresolved conflicts (see hg resolve, then hg rebase --continue)
  [1]

  $ cd $TESTTMP

Test rebasing when we're in the middle of a rebase already
  $ hg init test_issue6214
  $ cd test_issue6214
  $ echo r0 > r0
  $ hg ci -qAm 'r0'
  $ echo hi > foo
  $ hg ci -qAm 'hi from foo'
  $ hg co -q '.^'
  $ echo bye > foo
  $ hg ci -qAm 'bye from foo'
  $ hg co -q '.^'
  $ echo unrelated > some_other_file
  $ hg ci -qAm 'some unrelated changes'
  $ hg log -G -T'{rev}: {desc}\n{files%"{file}\n"}'
  @  3: some unrelated changes
  |  some_other_file
  | o  2: bye from foo
  |/   foo
  | o  1: hi from foo
  |/   foo
  o  0: r0
     r0
  $ hg rebase -r 2 -d 1 -t:merge3
  rebasing 2:b4d249fbf8dd "bye from foo"
  merging foo
  hit merge conflicts; re-running rebase without in-memory merge
  rebasing 2:b4d249fbf8dd "bye from foo"
  merging foo
  warning: conflicts while merging foo! (edit, then use 'hg resolve --mark')
  unresolved conflicts (see hg resolve, then hg rebase --continue)
  [1]
  $ hg rebase -r 3 -d 1 -t:merge3
  abort: rebase in progress
  (use 'hg rebase --continue' or 'hg rebase --abort')
  [255]
  $ hg resolve --list
  U foo
  $ hg resolve --all --re-merge -t:other
  (no more unresolved files)
  continue: hg rebase --continue
  $ hg rebase --continue
  rebasing 2:b4d249fbf8dd "bye from foo"
  saved backup bundle to $TESTTMP/test_issue6214/.hg/strip-backup/b4d249fbf8dd-299ec25c-rebase.hg
  $ hg log -G -T'{rev}: {desc}\n{files%"{file}\n"}'
  o  3: bye from foo
  |  foo
  | @  2: some unrelated changes
  | |  some_other_file
  o |  1: hi from foo
  |/   foo
  o  0: r0
     r0