[PATCH] gitk: Ignore ctrl-z as EOF on windows

Cygwin's Tcl is configured to honor any occurence of ctrl-z as an
end-of-file marker, while some commits in the git repository and possibly
elsewhere include that character in the commit comment. This causes gitk
ignore commit history following such a comment and incorrect graphs. This
change affects only Windows as Tcl on other platforms already has
eofchar == {}. This fixes problems noted by me and by Ray Lehtiniemi, and
the fix was suggested by Shawn Pierce.

Signed-off-by: Mark Levedahl <mdl123@verizon.net>
Signed-off-by: Paul Mackerras <paulus@samba.org>

gitk

@@ -101,7 +101,7 @@ proc start_rev_list {view} {
     set commfd($view) $fd
     set leftover($view) {}
     set lookingforhead $showlocalchanges
-    fconfigure $fd -blocking 0 -translation lf
+    fconfigure $fd -blocking 0 -translation lf -eofchar {}
     if {$tclencoding != {}} {
 	fconfigure $fd -encoding $tclencoding
     }