[PATCH 1 of 2] opener: add new resetflags param to __call__

[Adrian Buehlmann]

# HG changeset patch
# User Adrian Buehlmann <adrian at cadifra.com>
# Date 1291450283 -3600
# Node ID d117e5fec89474724361f2618eddbae350ba29d1
# Parent  6b8d2ee24ce2fb5d88dc201aa792ad878d06b92a
opener: add new resetflags param to __call__

If True, the flags of a preexisting normal file are reset on 'w'rite.
Defaults to False, which preserves the flags of normal files.

diff --git a/mercurial/util.py b/mercurial/util.py
--- a/mercurial/util.py
+++ b/mercurial/util.py
@@ -871,7 +871,8 @@ class opener(object):
             return
         os.chmod(name, self.createmode & 0666)
 
-    def __call__(self, path, mode="r", text=False, atomictemp=False):
+    def __call__(self, path, mode="r", text=False, atomictemp=False,
+                 resetflags=False):
         self.auditor(path)
         f = os.path.join(self.base, path)
 
@@ -890,7 +891,8 @@ class opener(object):
                 return atomictempfile(f, mode, self.createmode)
             try:
                 if 'w' in mode:
-                    st_mode = os.lstat(f).st_mode & 0777
+                    if not resetflags:
+                        st_mode = os.lstat(f).st_mode & 0777
                     os.unlink(f)
                     nlink = 0
                 else: