merge: demonstrate that directory renames can lose local file content

When a directory has been renamed on the local branch and a file has
been added in the old location on a remote branch, we move that new
file to the new location. Unfortunately, if there is already a file
there, we overwrite it with the contents from the remote branch. For
untracked local files, we should probably abort, and for tracked local
files, we should merge the contents. To start with, let's add a test
to demonstrate the breakage. Also note that while files merged in from
a remote branch are normally (and unintuitively) reported as modified,
these files are reported as added.

tests/test-rename-dir-merge.t

@@ -1,157 +1,192 b''
   $ 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
   updating: a/b 2/5 files (40.00%)
    b/a: remote created -> g
   getting b/a
    b/b: remote created -> g
   getting b/b
   updating: b/b 4/5 files (80.00%)
    b/c: remote directory rename - move from a/c -> dm
   updating: b/c 5/5 files (100.00%)
   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
   updating: b/c 1/1 files (100.00%)
   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.
+
+BROKEN: the uncommitted file is overwritten; we should abort
+
+  $ hg co -qC 1
+  $ echo local > 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
+  $ cat b/c
+  baz
+
+Local directory rename with conflicting file added in remote source directory
+and committed in local target directory.
+
+BROKEN: the local file is overwritten; it should be merged
+
+  $ hg co -qC 1
+  $ echo local > b/c
+  $ hg add b/c
+  $ hg commit -qm 'new file in target directory'
+  $ 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
+  $ cat b/c
+  baz
 
 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 ..