Emacs 23 fails to send Unicode combining diacritics through XWin -clipboard

Question

Emacs 23 is running on a remote Linux box. It displays its frame on this local Windows box, using Cygwin's X server. I used to be able to copy-paste any text from Emacs to any Windows application. Since after I upgraded from release 22 to 23, combining diacritics don't come through any more.

Non-combined characters pass unharmed. For example, é (U+00E9, LATIN SMALL LETTER E WITH ACUTE) passes, whereas the (U+0065, U+0301) combination (LATIN SMALL LETTER E, COMBINING ACUTE ACCENT) does not: it comes out as e+Z

Such sequences still pass fine from Emacs to other X applications. They still pass fine from Emacs to X applications running on different boxes. They still pass fine from Emacs to local X applications. But when they get to cross the line between X and Windows, it stops working.

The only change that happened to the chain in months is that Emacs upgrade. The rest is untouched.

In case it's of any help, XWin is lauched with the following command line:

exec XWin -clipboard -nowinkill -nounixkill -lesspointer -multiwindow

Answer 1

strangely enough, c/p from an xforwarded emacs works for me now with 23 and XMing, whereas with 22 it didn't.

Answer 2

Looking through the emacs 23 changelist (not something I do often) I see some suspicious mentions of 1) switching to a superset of Unicode (what the hell is that about??) and 2) switching to a modified utf-8 encoding internally (srsly?).

It could be quite possible that there is a bug in the implementation of either of these which might lead to the problems you are seeing. It's also possible, although much less likely, that there is a bug in xwin, and even less likely that there is a bug on the windows side.