windows: revlog.lazyparser not always safe to use.

windows: revlog.lazyparser not always safe to use.
can not use on windows < nt or if win32 api not available.

--- a/mercurial/revlog.py	Wed May 10 10:32:24 2006 -0700
+++ b/mercurial/revlog.py	Wed May 10 11:10:18 2006 -0700
@@ -87,6 +87,13 @@
     """
     this class avoids the need to parse the entirety of large indices
     """
+
+    # lazyparser is not safe to use on windows if win32 extensions not
+    # available. it keeps file handle open, which make it not possible
+    # to break hardlinks on local cloned repos.
+    safe_to_use = os.name != 'nt' or (not util.is_win_9x() and
+                                      hasattr(util, 'win32api'))
+
     def __init__(self, dataf, size, indexformat, shaoffset):
         self.dataf = dataf
         self.format = indexformat
@@ -362,7 +369,8 @@
             shaoffset = ngshaoffset
 
         if i:
-            if not self.inlinedata() and st and st.st_size > 10000:
+            if (lazyparser.safe_to_use and not self.inlinedata() and
+                st and st.st_size > 10000):
                 # big index, let's parse it on demand
                 parser = lazyparser(f, st.st_size, self.indexformat, shaoffset)
                 self.index = lazyindex(parser)

--- a/mercurial/util.py	Wed May 10 10:32:24 2006 -0700
+++ b/mercurial/util.py	Wed May 10 11:10:18 2006 -0700
@@ -489,6 +489,13 @@
 
 posixfile = file
 
+def is_win_9x():
+    '''return true if run on windows 95, 98 or me.'''
+    try:
+        return sys.getwindowsversion()[3] == 1
+    except AttributeError:
+        return os.name == 'nt' and 'command' in os.environ.get('comspec', '')
+
 # Platform specific variants
 if os.name == 'nt':
     demandload(globals(), "msvcrt")
@@ -570,6 +577,8 @@
     try:
         # override functions with win32 versions if possible
         from util_win32 import *
+        if not is_win_9x():
+            posixfile = posixfile_nt
     except ImportError:
         pass
 

--- a/mercurial/util_win32.py	Wed May 10 10:32:24 2006 -0700
+++ b/mercurial/util_win32.py	Wed May 10 11:10:18 2006 -0700
@@ -183,11 +183,11 @@
     filename = win32process.GetModuleFileNameEx(proc, 0)
     return [os.path.join(os.path.dirname(filename), 'mercurial.ini')]
 
-class posixfile(object):
+class posixfile_nt(object):
     '''file object with posix-like semantics.  on windows, normal
     files can not be deleted or renamed if they are open. must open
     with win32file.FILE_SHARE_DELETE. this flag does not exist on
-    windows <= nt.'''
+    windows < nt, so do not use this class there.'''
 
     # tried to use win32file._open_osfhandle to pass fd to os.fdopen,
     # but does not work at all. wrap win32 file api instead.