Path: utzoo!utgpu!news-server.csri.toronto.edu!smoke.cs.toronto.edu!neat.cs.toronto.edu!moraes
Newsgroups: comp.windows.x
From: moraes@cs.toronto.edu (Mark Moraes)
Subject: Re: Xterm dies in tek mode
Message-ID: <90Sep17.174858edt.382@smoke.cs.toronto.edu>
Organization: Department of Computer Science, University of Toronto
References: <167855@teemc.UUCP>
Date: 17 Sep 90 21:49:58 GMT
Lines: 106

wayne@teemc.UUCP (Michael R. Wayne) writes:
>	Every time I try to use xterm in tek mode, it dies.  gdb on xterm -t
>tells me the problem is in the library routine XmuCopyISOLatinLowered called
>from TekRealize at line 1292 of xterm/Tekproc.c.  Is there a patch to deal
>with this one?

Here's a copy of a bug report we filed with xbugs in January --
strictly unblessed and unsupported, of course!

From: jonah@dgp.toronto.edu
To: xbugs@expo.lcs.mit.edu
Subject: xterm core dumps when openning tek window

			  X Window System Bug Report
			    xbugs@expo.lcs.mit.edu


VERSION:
    R4

CLIENT MACHINE and OPERATING SYSTEM:
    Sun 3/280 running SunOS 3.5

DISPLAY TYPE:
    Sun /dev/fb (mono)

WINDOW MANAGER:
    twm

AREA:
    xterm/Xaw/Xmu/Xt

SYNOPSIS:
    When I try to open the tek window in xterm, xterm just quits with
    a "memory fault"

DESCRIPTION:
    In Texproc.c, XmuCopyISOLatin1Lowered is called with the same string
    for the source and destination -- but the string comes from the toolkit
    and might be a static (non-writable) string.

	(gdb) bt
	#0  0x1734c in XmuCopyISOLatin1Lowered ()
	#1  0x1013a in TekRun ()
	#2  0x22fd8 in _XtIsSubclassOf ()
	#3  0x23074 in _XtIsSubclassOf ()
	#4  0x23108 in XtRealizeWidget ()
	#5  0xfa1e in TekRun ()
	#6  0x3824 in main ()

REPEAT BY:
    Compile xterm, Xaw, Xt, and Xmu with gcc (1.35) but without
    -fwritable-strings.  Start-up an xterm and try to open a tek window
    from the menu.  Run gdb and look at the backtrace.

    Note: Before you get to this bug, you may have to compensate for the
    fact that many libraries have a broken sscanf() which may also try to
    modify a ``const'' (ANSI C) string argument.  We'd send you the fix to
    this one too, but it's a patch to non-redistributable code.

SAMPLE FIX:

*** /tmp/,RCSt1a00417	Thu Jan 18 21:48:06 1990
--- mit/clients/xterm/Tekproc.c	Thu Jan 18 21:18:14 1990
***************
*** 1288,1303 ****
      screen->cur.fontsize = TEK_FONT_LARGE;
      if (tw->tek.initial_font) {
  	char *s = tw->tek.initial_font;
  
! 	XmuCopyISOLatin1Lowered (s, s);
! 	if (strcmp (s, "large") == 0)
  	  screen->cur.fontsize = TEK_FONT_LARGE;
! 	else if (strcmp (s, "2") == 0 || strcmp (s, "two") == 0)
  	  screen->cur.fontsize = TEK_FONT_2;
! 	else if (strcmp (s, "3") == 0 || strcmp (s, "three") == 0)
  	  screen->cur.fontsize = TEK_FONT_3;
! 	else if (strcmp (s, "small") == 0)
  	  screen->cur.fontsize = TEK_FONT_SMALL;
      }
  
      gcv.graphics_exposures = TRUE;	/* default */
--- 1288,1309 ----
      screen->cur.fontsize = TEK_FONT_LARGE;
      if (tw->tek.initial_font) {
  	char *s = tw->tek.initial_font;
+ 	char *slow = (char*) malloc(strlen(s)+1);
  
!         if (slow == (char*)NULL) {
! 	    fprintf(stderr, "%s: malloc failed\n", xterm_name);
! 	    goto mallocfailed;
! 	}
! 	XmuCopyISOLatin1Lowered (slow, s);
! 	if (strcmp (slow, "large") == 0)
  	  screen->cur.fontsize = TEK_FONT_LARGE;
! 	else if (strcmp (slow, "2") == 0 || strcmp (slow, "two") == 0)
  	  screen->cur.fontsize = TEK_FONT_2;
! 	else if (strcmp (slow, "3") == 0 || strcmp (slow, "three") == 0)
  	  screen->cur.fontsize = TEK_FONT_3;
! 	else if (strcmp (slow, "small") == 0)
  	  screen->cur.fontsize = TEK_FONT_SMALL;
+ 	free(slow);
      }
  
      gcv.graphics_exposures = TRUE;	/* default */