using the -W option of vim

Question

the -w and -W options of vim have theoretically the following effect:

-w {scriptout} All the characters that you type are

Answer 1

My best guess is that this is a bug in the GUI code of gVim.

Using gVim 7.3, if I run gvim -u NONE -W scriptout then I see the problem, but if I run vim -u NONE -W scriptout then the unwanted bytes are not present.

I also tested Vim 7.2 from the shell in Linux, the version of Vim included in Snow Leopard (7.2), and the GUI and terminal versions of MacVim 7.2 (with mvim -W and /Applications/MacVim/Contents/MacOS/Vim -W, respectively) and they all worked correctly.