view tests/test-rename-dir-merge.t @ 46667:93e9f448273c

rhg: Add support for automatic fallback to Python

`rhg` is a command-line application that can do a small subset of what
`hg` can. It is written entirely in Rust, which avoids the cost of starting
a Python interpreter and importing many Python modules.
In a script that runs many `hg` commands, this cost can add up.

However making users decide when to use `rhg` instead of `hg` is
not practical as we want the subset of supported functionality
to grow over time.

Instead we introduce "fallback" behavior where, when `rhg` encounters
something (a sub-command, a repository format, …) that is not implemented
in Rust-only, it does nothing but silently start a subprocess of
Python-based `hg` running the same command.
That way `rhg` becomes a drop-in replacement for `hg` that sometimes
goes faster. Whether Python is used should be an implementation detail
not apparent to users (other than through speed).

A new `fallback` value is added to the previously introduced
`rhg.on-unsupported` configuration key. When in this mode, the new
`rhg.fallback-executable` config is determine what command to use
to run a Python-based `hg`.

The previous `rhg.on-unsupported = abort-silent` configuration was designed
to let a wrapper script call `rhg` and then fall back to `hg` based on the
exit code. This is still available, but having fallback behavior built-in
in rhg might be easier for users instead of leaving that script "as an
exercise for the reader".

Using a subprocess like this is not idea, especially when `rhg` is to be
installed in `$PATH` as `hg`, since the other `hg.py` executable needs
to still be available… somewhere. Eventually this could be replaced
by using PyOxidizer to a have a single executable that embeds a Python
interpreter, but only starts it when needed.

Differential Revision: https://phab.mercurial-scm.org/D10093

  $ hg init t
  $ cd t

  $ mkdir a
  $ echo foo > a/a
  $ echo bar > a/b
  $ hg ci -Am "0"
  adding a/a
  adding a/b

  $ hg co -C 0
  0 files updated, 0 files merged, 0 files removed, 0 files unresolved
  $ hg mv a b
  moving a/a to b/a
  moving a/b to b/b
  $ hg ci -m "1 mv a/ b/"

  $ hg co -C 0
  2 files updated, 0 files merged, 2 files removed, 0 files unresolved
  $ echo baz > a/c
  $ echo quux > a/d
  $ hg add a/c
  $ hg ci -m "2 add a/c"
  created new head

  $ hg merge --debug 1
    unmatched files in local:
     a/c
    unmatched files in other:
     b/a
     b/b
    all copies found (* = to merge, ! = divergent, % = renamed and deleted):
     on remote side:
      src: 'a/a' -> dst: 'b/a' 
      src: 'a/b' -> dst: 'b/b' 
    checking for directory renames
     discovered dir src: 'a/' -> dst: 'b/'
     pending file src: 'a/c' -> dst: 'b/c'
  resolving manifests
   branchmerge: True, force: False, partial: False
   ancestor: f9b20c0d4c51, local: ce36d17b18fb+, remote: 397f8b00a740
   a/a: other deleted -> r
  removing a/a
   a/b: other deleted -> r
  removing a/b
   b/a: remote created -> g
  getting b/a
   b/b: remote created -> g
  getting b/b
   b/c: remote directory rename - move from a/c -> dm
  moving a/c to b/c
  3 files updated, 0 files merged, 2 files removed, 0 files unresolved
  (branch merge, don't forget to commit)

  $ echo a/* b/*
  a/d b/a b/b b/c
  $ hg st -C
  M b/a
  M b/b
  A b/c
    a/c
  R a/a
  R a/b
  R a/c
  ? a/d
  $ hg ci -m "3 merge 2+1"
  $ hg debugrename b/c
  b/c renamed from a/c:354ae8da6e890359ef49ade27b68bbc361f3ca88

  $ hg co -C 1
  0 files updated, 0 files merged, 1 files removed, 0 files unresolved
  $ hg merge --debug 2
    unmatched files in local:
     b/a
     b/b
    unmatched files in other:
     a/c
    all copies found (* = to merge, ! = divergent, % = renamed and deleted):
     on local side:
      src: 'a/a' -> dst: 'b/a' 
      src: 'a/b' -> dst: 'b/b' 
    checking for directory renames
     discovered dir src: 'a/' -> dst: 'b/'
     pending file src: 'a/c' -> dst: 'b/c'
  resolving manifests
   branchmerge: True, force: False, partial: False
   ancestor: f9b20c0d4c51, local: 397f8b00a740+, remote: ce36d17b18fb
  starting 4 threads for background file closing (?)
   b/c: local directory rename - get from a/c -> dg
  getting a/c to b/c
  1 files updated, 0 files merged, 0 files removed, 0 files unresolved
  (branch merge, don't forget to commit)

  $ echo a/* b/*
  a/d b/a b/b b/c
  $ hg st -C
  A b/c
    a/c
  ? a/d
  $ hg ci -m "4 merge 1+2"
  created new head
  $ hg debugrename b/c
  b/c renamed from a/c:354ae8da6e890359ef49ade27b68bbc361f3ca88

Local directory rename with conflicting file added in remote source directory
and untracked in local target directory.

  $ hg co -qC 1
  $ echo target > b/c
  $ hg merge 2
  b/c: untracked file differs
  abort: untracked files in working directory differ from files in requested revision
  [20]
  $ cat b/c
  target
but it should succeed if the content matches
  $ hg cat -r 2 a/c > b/c
  $ hg merge 2
  1 files updated, 0 files merged, 0 files removed, 0 files unresolved
  (branch merge, don't forget to commit)
  $ hg st -C
  A b/c
    a/c
  ? a/d

Local directory rename with conflicting file added in remote source directory
and committed in local target directory.

  $ hg co -qC 1
  $ echo target > b/c
  $ hg add b/c
  $ hg commit -qm 'new file in target directory'
  $ hg merge 2
  merging b/c and a/c to b/c
  warning: conflicts while merging b/c! (edit, then use 'hg resolve --mark')
  0 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 st -A
  M b/c
    a/c
  ? a/d
  ? b/c.orig
  C b/a
  C b/b
  $ cat b/c
  <<<<<<< working copy: f1c50ca4f127 - test: new file in target directory
  target
  =======
  baz
  >>>>>>> merge rev:    ce36d17b18fb - test: 2 add a/c
  $ rm b/c.orig

Remote directory rename with conflicting file added in remote target directory
and committed in local source directory.

  $ hg co -qC 2
  $ hg st -A
  ? a/d
  C a/a
  C a/b
  C a/c
  $ hg merge 5
  merging a/c and b/c to b/c
  warning: conflicts while merging b/c! (edit, then use 'hg resolve --mark')
  2 files updated, 0 files merged, 2 files removed, 1 files unresolved
  use 'hg resolve' to retry unresolved file merges or 'hg merge --abort' to abandon
  [1]
  $ hg st -A
  M b/a
  M b/b
  M b/c
    a/c
  R a/a
  R a/b
  R a/c
  ? a/d
  ? b/c.orig
  $ cat b/c
  <<<<<<< working copy: ce36d17b18fb - test: 2 add a/c
  baz
  =======
  target
  >>>>>>> merge rev:    f1c50ca4f127 - test: new file in target directory

Second scenario with two repos:

  $ cd ..
  $ hg init r1
  $ cd r1
  $ mkdir a
  $ echo foo > a/f
  $ hg add a
  adding a/f
  $ hg ci -m "a/f == foo"
  $ cd ..

  $ hg clone r1 r2
  updating to branch default
  1 files updated, 0 files merged, 0 files removed, 0 files unresolved
  $ cd r2
  $ hg mv a b
  moving a/f to b/f
  $ echo foo1 > b/f
  $ hg ci -m" a -> b, b/f == foo1"
  $ cd ..

  $ cd r1
  $ mkdir a/aa
  $ echo bar > a/aa/g
  $ hg add a/aa
  adding a/aa/g
  $ hg ci -m "a/aa/g"
  $ hg pull ../r2
  pulling from ../r2
  searching for changes
  adding changesets
  adding manifests
  adding file changes
  added 1 changesets with 1 changes to 1 files (+1 heads)
  new changesets 7d51ed18da25
  1 local changesets published
  (run 'hg heads' to see heads, 'hg merge' to merge)

  $ hg merge
  2 files updated, 0 files merged, 1 files removed, 0 files unresolved
  (branch merge, don't forget to commit)

  $ hg st -C
  M b/f
  A b/aa/g
    a/aa/g
  R a/aa/g
  R a/f

  $ cd ..

Test renames to separate directories

  $ hg init a
  $ cd a
  $ mkdir a
  $ touch a/s
  $ touch a/t
  $ hg ci -Am0
  adding a/s
  adding a/t

Add more files

  $ touch a/s2
  $ touch a/t2
  $ hg ci -Am1
  adding a/s2
  adding a/t2

Do moves on a branch

  $ hg up 0
  0 files updated, 0 files merged, 2 files removed, 0 files unresolved
  $ mkdir s
  $ mkdir t
  $ hg mv a/s s
  $ hg mv a/t t
  $ hg ci -Am2
  created new head
  $ hg st --copies --change .
  A s/s
    a/s
  A t/t
    a/t
  R a/s
  R a/t

Merge shouldn't move s2, t2

  $ hg merge
  2 files updated, 0 files merged, 0 files removed, 0 files unresolved
  (branch merge, don't forget to commit)
  $ hg st --copies
  M a/s2
  M a/t2

Try the merge in the other direction. It may or may not be appropriate for
status to list copies here.

  $ hg up -C 1
  4 files updated, 0 files merged, 2 files removed, 0 files unresolved
  $ hg merge
  2 files updated, 0 files merged, 2 files removed, 0 files unresolved
  (branch merge, don't forget to commit)
  $ hg st --copies
  M s/s
  M t/t
  R a/s
  R a/t

  $ cd ..


Test that files are moved to a new directory based on the path prefix that
matches the most. dir1/ below gets renamed to dir2/, and dir1/subdir1/ gets
renamed to dir2/subdir2/. We want dir1/subdir1/newfile to move to
dir2/subdir2/ (not to dir2/subdir1/ as we would infer based on just the rename
of dir1/ to dir2/).

  $ hg init nested-renames
  $ cd nested-renames
  $ mkdir dir1
  $ echo a > dir1/file1
  $ echo b > dir1/file2
  $ mkdir dir1/subdir1
  $ echo c > dir1/subdir1/file3
  $ echo d > dir1/subdir1/file4
  $ hg ci -Aqm initial
  $ hg mv dir1 dir2
  moving dir1/file1 to dir2/file1
  moving dir1/file2 to dir2/file2
  moving dir1/subdir1/file3 to dir2/subdir1/file3
  moving dir1/subdir1/file4 to dir2/subdir1/file4
  $ hg mv dir2/subdir1 dir2/subdir2
  moving dir2/subdir1/file3 to dir2/subdir2/file3
  moving dir2/subdir1/file4 to dir2/subdir2/file4
  $ hg ci -m 'move dir1/ to dir2/ and dir1/subdir1/ to dir2/subdir2/'
  $ hg co 0
  4 files updated, 0 files merged, 4 files removed, 0 files unresolved
  $ echo e > dir1/subdir1/file5
  $ hg ci -Aqm 'add file in dir1/subdir1/'
  $ hg merge 1
  5 files updated, 0 files merged, 4 files removed, 0 files unresolved
  (branch merge, don't forget to commit)
  $ hg files
  dir2/file1
  dir2/file2
  dir2/subdir2/file3
  dir2/subdir2/file4
  dir2/subdir2/file5
  $ cd ..