[PATCH] manifestmerge: local unknown, remote created: don't traverse symlinks

[Siddharth Agarwal]

# HG changeset patch
# User Siddharth Agarwal <sid0 at fb.com>
# Date 1368047461 25200
#      Wed May 08 14:11:01 2013 -0700
# Node ID 0fc5b11beaa38d4ffde0bc61ee5f798b392cdd2e
# Parent  c4f58fe8798f11a2b851412b1b8f3d0e23c7ed29
manifestmerge: local unknown, remote created: don't traverse symlinks

To figure out what to do with locally unknown files, Mercurial attempts to read
them if they exist. When an attempt is made to read a file that exists but
traverses a symlink, Mercurial aborts.

With this patch, we first ensure that the file doesn't traverse a symlink
before opening it. This is fine because a file being "remote created" means the
symlink doesn't exist remotely, which means it will be deleted in the apply
phase.

diff --git a/mercurial/merge.py b/mercurial/merge.py
--- a/mercurial/merge.py
+++ b/mercurial/merge.py
@@ -95,6 +95,7 @@
 def _checkunknownfile(repo, wctx, mctx, f):
     return (not repo.dirstate._ignore(f)
         and os.path.isfile(repo.wjoin(f))
+        and repo.wopener.audit.check(f)
         and repo.dirstate.normalize(f) not in repo.dirstate
         and mctx[f].cmp(wctx[f]))
 
diff --git a/tests/test-symlinks.t b/tests/test-symlinks.t
--- a/tests/test-symlinks.t
+++ b/tests/test-symlinks.t
@@ -160,6 +160,15 @@
   adding bar/a
   adding foo
   removing foo/a
+
+commit and update back
+
+  $ hg ci -mb
+  $ hg up '.^'
+  1 files updated, 0 files merged, 2 files removed, 0 files unresolved
+  $ hg up tip
+  2 files updated, 0 files merged, 1 files removed, 0 files unresolved
+
   $ cd ..
 
 == root of repository is symlinked ==