problem with cygwin emacs and revert-buffer

["Swenson, Eric" <Eric dot Swenson at am dot sony dot com>]

I'm having a problem with emacs buffer corruption when I use the
revert-buffer command.  Buffer corruption *only* occurs when I use the
version of emacs (either emacs or emacs-nox) that comes with cygwin.  The
GNU emacs that build NOT for cygwin and NOT with the cygwin libraries (I
guess this is called NT Emacs, formerly downloaded form
ftp.cs.washington.edu) does NOT exhibit this buffer corrruption.

The problem occurs with cygwin 1.5.3-1, and emacs version 21.2.1
(i686-pc-cygwin, X toolkit).  It also occurs with the 21.2.1
(i686-pc-cygwin) version.  As I mentioned above, revert-buffer never
exhibits buffer corruption with GNU Emacs 21.1.1 (i386-msvc-nt5.1.2600),
which is the NT Emacs version I have.  

The problem is that frequently revert-buffer corrupts the buffer when the
on-disk version of a file has changed. The nature of the corruption is that
at the point where the cursor is (prior to executing revert-buffer), a block
of misplaced/duplicated text appears, followed by otherwise correct data.
Comparing the actual on-disk file contents with the result of revert-buffer
(which should be identical) shows a extraneous block of text (perhaps the
size of the difference in size between original and new) at the cursor.  If
the cursor is at the end of the file prior to the revert-buffer, the
extraneous text appears at the cursor as well (so it doesn't require the
cursor to be in the middle of the file). 

Note that I have also installed cygwin-kde3.1 -- and it was soon after I
installed this package, and switched from NT Emacs to the emacs that comes
with cygwin that I started noticing the problem.  Of course, I only started
using the version of emacs that comes with cygwin once I could run cygwin
under XFree86/KDE.  I have verified, however, that the problem appears
unrelated to the X toolkit and executing under XFree86.  Both running
emacs-nox (under KDE/XFree86) and running emacs (or emacs-nox) without
XFree86 results in the same revert-buffer buffer corruption problem.

I've searched the web for messages related to revert-buffer buffer
corruption and can only find references to use of revert-buffer and
jka-compr (which I don't think believe I'm using).  Although I was tempted
to believe this was an emacs problem, it would appear that since the problem
only occurs when I'm using the version of emacs built under cygwin (as
opposed to the NT Emacs version), that this problem is somehow related to
cygwin.  

Any advice would be most welcome.  Thanks.  -- Eric


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