On Mar 30, 2010, at 3:43 AM, Adrian Robert wrote:

>> One other thing I noticed which looking through the code is that the
>> Nextstep port assigns a special value, `t', to frame-title-format, and
>> processes it specially.  Is there any reason to do this?  If not, I
>> think this should be removed; this looks like a misfeature to me, since
>> it is not compatible with the variable as documented and can confuse
>> other people's Lisp code.
> 
> Ah, OK -- this variable and value was checked for in the code I moved in my patch, but I had no idea it was set specially by NS lisp code.  I'll look into it.

IIRC, NS displays the file's name as the title and requires you to set it that way if drag&drop of the file proxy icons (displayed next to the name of the frame) is supposed to work.  That's all standard functionality on NS or at least on the Mac.  If the frame name is different, I think drag&drop doesn't work right.  See xdisp.c:9503ff and also ns_set_name_as_filename() in nsfns.m.

Introducing a ns-* variable to override would confuse users (frame-title-format won't work as expected), but if we set the file name with this NS function iff ns-frame-title-format is "%f", then that would be consistent with the other platforms.