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From: carroll@s.cs.uiuc.edu
Newsgroups: comp.windows.x
Subject: GNU-Emacs vs. XLoadQueryFont()
Message-ID: <216500008@s.cs.uiuc.edu>
Date: 20 May 89 19:02:00 GMT
Lines: 35
Nf-ID: #N:s.cs.uiuc.edu:216500008:000:2053
Nf-From: s.cs.uiuc.edu!carroll    May 20 14:02:00 1989


I'm at loss on this one.

Setup: Hacking GNU-Emacs 18.52 to use multiple X-windows (which I call
"screens", to differentiate from Emacs-windows).

Problem: I've got it mostly working, but in trying to install defaults
processing I've broken it. Currently, it stores command line/.Xdefaults
specifications in a screen-defaults structure. This is passed to the
screen-creator function to actually create a screen. This works fine
for the two initial screens (an edit screen and the minibuff screen). However,
after that Emacs fudges the X-connection numbers and sets up IO handlers to
grab all the X-windows IO. When I try to create another screen, the
screen-creator calls XLoadQueryFont() to set up a font for the new screen
(which could have been changed since the intial creation). At this point
everything locks up, and I get a bunch of messages of the form
Xlib:  sequence lost (0x1000a > 0x15c) in reply type 0x0!
These seem to be X-events that are getting lost (e.g., they stop after a
bit, and are afterwards generated by moving the cursor in/out of the screen).
Emacs uses a procudure to read input (internal_socket_read()), and I have
a trap for any event that's not one of the standard types, but it's not
tripping. But if I core-dump it (by kill -6 <job number>), the core image
claims that it's in internal_socket_read(). I strongly suspect that the
problem is contention between internal_socket_read() and XLoadQueryFont()
in trying to talk to the server.

Request: Any hints at all would be appreciated. In particuar, can anyone
give me some pointers to where to look for information on this sort of
thing? I _don't_ want to spend the next 2 months reading the entire X-docs.
Can I tap into the protocol exchange? What does QueryFont() say to the server,
and what does it send in reply? What X-doc talks about this? Many thanks!

Alan M. Carroll                "And there you are
carroll@s.cs.uiuc.edu           Saying 'We have the Moon, so now the Stars...'"
CS Grad / U of Ill @ Urbana    ...{ucbvax,pur-ee,convex}!s.cs.uiuc.edu!carroll