[PATCH stable] dirstate.walk: don't report same file stat multiple times

[Martin von Zweigbergk]

# HG changeset patch
# User Martin von Zweigbergk <martinvonz at google.com>
# Date 1428209652 25200
#      Sat Apr 04 21:54:12 2015 -0700
# Branch stable
# Node ID df4b2a1b51a30bd4b021b479d871864cce4886e9
# Parent  2e2e9a0750f91a6fe0ad88e4de34f8efefdcab08
dirstate.walk: don't report same file stat multiple times

dirstate.walk() generates pairs of filename and a stat-like
object. After "hg mv foo Foo", it generates one pair for "foo" and one
for "Foo", as it should. However, on case-insensitive file systems,
when it tries to stat to get the disk state as well, it gets the same
stat result for both names. This confuses at least
scmutil._interestingfiles(), making it think that "foo" was forgotten
rather than removed. That, in turn, makes "hg addremove" add "foo"
back, resulting in both cases in the dirstate, as reported in
issue4590.

This change only takes care of the "if unknown" branch. A similar fix
should perhaps be applied to the other branch.

diff -r 2e2e9a0750f9 -r df4b2a1b51a3 mercurial/dirstate.py
--- a/mercurial/dirstate.py	Tue Mar 31 20:20:17 2015 -0300
+++ b/mercurial/dirstate.py	Sat Apr 04 21:54:12 2015 -0700
@@ -793,9 +793,15 @@
                 audit_path = pathutil.pathauditor(self._root)
 
                 for nf in iter(visit):
+                    # If a stat for the same file was already added with a
+                    # different case, don't add one for this, since that would
+                    # make it appear as if the file exists under both names
+                    # on disk.
+                    if normalize and normalize(nf, True, True) in results:
+                        results[nf] = None
                     # Report ignored items in the dmap as long as they are not
                     # under a symlink directory.
-                    if audit_path.check(nf):
+                    elif audit_path.check(nf):
                         try:
                             results[nf] = lstat(join(nf))
                             # file was just ignored, no links, and exists
diff -r 2e2e9a0750f9 -r df4b2a1b51a3 tests/test-casefolding.t
--- a/tests/test-casefolding.t	Tue Mar 31 20:20:17 2015 -0300
+++ b/tests/test-casefolding.t	Sat Apr 04 21:54:12 2015 -0700
@@ -37,6 +37,15 @@
   $ hg mv A a
   $ hg st
 
+addremove after case-changing rename has no effect (issue4590)
+
+  $ hg mv a A
+  $ hg addremove
+  recording removal of a as rename to A (100% similar)
+  $ hg revert --all
+  forgetting A
+  undeleting a
+
 test changing case of path components
 
   $ mkdir D