win32: backout 1a9ebc83a74c
This change conflicted with TortoiseHg's use of QFileSystemWatcher. Files which
were being monitored (for file-system events) were unable to be reliably updated
using util.atomictempfile. Often the update would error out in the middle of
the process leaving neither the old or the new file in place.
My guess is that _kernel32.CreateFileA() is triggering an exception that is
not handled correctly within unlink()
$ hg init
$ cat > a <<EOF
> a
> b
> c
> EOF
$ hg ci -Am adda
adding a
$ cat > a <<EOF
> d
> e
> f
> EOF
$ hg ci -m moda
$ hg diff --reverse -r0 -r1
diff -r 2855cdcfcbb7 -r 8e1805a3cf6e a
--- a/a Thu Jan 01 00:00:00 1970 +0000
+++ b/a Thu Jan 01 00:00:00 1970 +0000
@@ -1,3 +1,3 @@
-d
-e
-f
+a
+b
+c
$ cat >> a <<EOF
> g
> h
> EOF
$ hg diff --reverse --nodates
diff -r 2855cdcfcbb7 a
--- a/a
+++ b/a
@@ -1,5 +1,3 @@
d
e
f
-g
-h