tests/test-rename-dir-merge.t

match: introduce boolean prefix() method

tl;dr: This is another step towards a (previously unstated) goal of
eliminating match.files() in conditions.

There are four types of matchers:

 * always: Matches everything, checked with always(), files() is empty

 * exact: Matches exact set of files, checked with isexact(), files()
   contains the files to match

 * patterns: Matches more complex patterns, checked with anypats(),
   files() contains roots of the matched patterns

 * prefix: Matches simple 'path:' patterns as prefixes ('foo' matches
   both 'foo' and 'foo/bar'), no single method to check, files()
   contains the prefixes to match

For completeness, it would be nice to have a method for checking for
the "prefix" type of matcher as well, so let's add that, making it
return True simply when none of the others do.

The larger goal here is to eliminate uses of match.files() in
conditions (i.e. bool(match.files())). The reason for this is that
there are scenarios when you would like to create a "prefix" matcher
that happens to match no files. One example is for 'hg files -I foo
bar'. The narrowmatcher also restricts the set of files given and it
would not surprise me if have bugs caused by that already. Note that
'if m.files() and not m.anypats()' and similar is sometimes used to
catch the "exact" and "prefix" cases above.

  $ 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 (glob)
  moving a/b to b/b (glob)
  $ 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
    searching for copies back to rev 1
    unmatched files in local:
     a/c
    unmatched files in other:
     b/a
     b/b
    all copies found (* = to merge, ! = divergent, % = renamed and deleted):
     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 (glob)
  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 (glob)

  $ hg co -C 1
  0 files updated, 0 files merged, 1 files removed, 0 files unresolved
  $ hg merge --debug 2
    searching for copies back to rev 1
    unmatched files in local:
     b/a
     b/b
    unmatched files in other:
     a/c
    all copies found (* = to merge, ! = divergent, % = renamed and deleted):
     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
   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 (glob)

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
  [255]
  $ 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 during merge.
  merging b/c incomplete! (edit conflicts, 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 update -C .' 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
  <<<<<<< local: f1c50ca4f127 - test: new file in target directory
  target
  =======
  baz
  >>>>>>> other: 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 during merge.
  merging b/c incomplete! (edit conflicts, 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 update -C .' 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
  <<<<<<< local: ce36d17b18fb  - test: 2 add a/c
  baz
  =======
  target
  >>>>>>> other: 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 (glob)
  $ 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 (glob)
  $ 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 (glob)
  $ 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)
  (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 ..