bug#10840: 24.0.93; No `man' command completion on Windows (using Cygwin for man pages)

[Drew Adams]

I have Cygwin installed (a rather old version; dunno which one or how to
tell).  I load `cygwin-mount.el', then `setup-cygwin.el', both of which
are available on EmacsWiki:
 
http://www.emacswiki.org/emacs/download/cygwin-mount.el
http://www.emacswiki.org/emacs/download/setup-cygwin.el
 
emacs -Q
 
M-x man RET
 
Hitting TAB (with no minibuffer input) completes the empty input to the
two chars `^:'.  Thereafter I can do nothing with that.  Whether I type
anything after the `^:' or not, TAB just completes to `^:'.
 
If I instead first type `l' (as in `ls') and then hit TAB, I get [No
match].  It doesn't seem to matter what I type in the minibuffer: TAB
always says [No match].
 
(I can of course enter a complete command name, such as `ls' and hit
RET.  `man' then works correctly.  It is only the UNIX command-name
completion that is seemingly broken.
 
Am I missing something?  I tried to debug this a bit but wasn't
successful in following what was happening.  Please advise.  Thx.
 

In GNU Emacs 24.0.93.1 (i386-mingw-nt5.1.2600)
 of 2012-02-15 on MARVIN
Windowing system distributor `Microsoft Corp.', version 5.1.2600
Configured using:
 `configure --with-gcc (4.6) --no-opt --enable-checking --cflags
 -ID:/devel/emacs/libs/libXpm-3.5.8/include
 -ID:/devel/emacs/libs/libXpm-3.5.8/src
 -ID:/devel/emacs/libs/libpng-dev_1.4.3-1/include
 -ID:/devel/emacs/libs/zlib-dev_1.2.5-2/include
 -ID:/devel/emacs/libs/giflib-4.1.4-1/include
 -ID:/devel/emacs/libs/jpeg-6b-4/include
 -ID:/devel/emacs/libs/tiff-3.8.2-1/include
 -ID:/devel/emacs/libs/gnutls-3.0.9/include'