Debian Bug report logs - #287360
tk8.4: segfaults because it can't handle some X font aliases

Toggle useless messages

Message #5 received at submit@bugs.debian.org (full text, mbox, reply):

From: Takahide HIGUCHI <h2@hima.jp>

To: Debian Bug Tracking System <submit@bugs.debian.org>

Subject: tk8.4: segfaults because it can't handle some X font aliases

Date: Mon, 27 Dec 2004 20:01:21 +0900 (JST)

Package: tk8.4
Version: 8.4.7-1
Severity: important

How to reproduce: 

1. install 'xfonts-mplus' and 'xmaxima' package

2. run 'xmaxima' command. It will result segmentation fault.

   I also confirmed that a test program in the tk8.4 source
   (tests/unixFont.test) fails.
   


Details of the bug:

The font aliases of the X window system, which can be very short string.
My output of xlsfonts command contains like following:

...
mplus_f12r           
mplus_f12r
...
naga10
naga10b
...
a12
k12
...


TkpGetFontFamilies() function in tk8.4 source assumes that font names
are always in the form of XLFD (X Logical Font Description), such as:

     '-misc-fixed-medium-r-normal--7-70-75-75-c-50-iso8859-1'
     '-misc-fixed-medium-r-normal--8-80-75-75-c-50-iso8859-1'

Hence TkpGetFontFamilies() function will fail to parse font aliases 
which does not contain two '-' characters.


Proposed patch: 

Following patch makes tk8.4 not to assume there is a font family 
in given font name or font aliase.


diff -ruN tk8.4-8.4.7.original/unix/tkUnixFont.c tk8.4-8.4.7/unix/tkUnixFont.c
--- tk8.4-8.4.7.original/unix/tkUnixFont.c	2003-10-29 10:07:46.000000000 +0900
+++ tk8.4-8.4.7/unix/tkUnixFont.c	2004-12-27 19:09:44.000000000 +0900
@@ -839,6 +839,7 @@
 {
     int i, new, numNames;
     char *family;
+    char *family_endp;
     Tcl_HashTable familyTable;
     Tcl_HashEntry *hPtr;
     Tcl_HashSearch search;
@@ -850,9 +851,14 @@
     Tcl_InitHashTable(&familyTable, TCL_STRING_KEYS);
     nameList = ListFonts(Tk_Display(tkwin), "*", &numNames);
     for (i = 0; i < numNames; i++) {
-	family = strchr(nameList[i] + 1, '-') + 1;
-	strchr(family, '-')[0] = '\0';
-	Tcl_CreateHashEntry(&familyTable, family, &new);
+	family = strchr(nameList[i] + 1, '-');
+	if(family) {
+	  family_endp = strchr(family + 1, '-');
+	  if(family_endp) {
+	    family_endp[0] = '\0';
+	    Tcl_CreateHashEntry(&familyTable, family, &new);
+	  }
+	}
     }
     XFreeFontNames(nameList);
 



-- System Information:
Debian Release: 3.1
  APT prefers testing
  APT policy: (500, 'testing')
Architecture: i386 (i686)
Kernel: Linux 2.6.9
Locale: LANG=C, LC_CTYPE=C (charmap=ANSI_X3.4-1968)

Versions of packages tk8.4 depends on:
ii  libc6                     2.3.2.ds1-18   GNU C Library: Shared libraries an
ii  libx11-6                  4.3.0.dfsg.1-8 X Window System protocol client li
ii  tcl8.4                    8.4.7-1        Tcl (the Tool Command Language) v8
ii  xlibs                     4.3.0.dfsg.1-8 X Window System client libraries m

-- no debconf information

Message #10 received at 287360@bugs.debian.org (full text, mbox, reply):

From: Chris Waters <xtifr@debian.org>

To: Takahide HIGUCHI <h2@hima.jp>, 287360@bugs.debian.org

Subject: Re: Bug#287360: tk8.4: segfaults because it can't handle some X font aliases

Date: Wed, 29 Dec 2004 00:50:44 -0800

On Mon, Dec 27, 2004 at 08:01:21PM +0900, Takahide HIGUCHI wrote:

> The font aliases of the X window system, which can be very short string.
[...]

> TkpGetFontFamilies() function in tk8.4 source assumes that font names
> are always in the form of XLFD (X Logical Font Description)

Hmm, that's very strange.  Even a bare-bones installation of X
contains font aliases such as "fixed" and "olglyph-10".  Do you have
any idea why *those* don't cause a crash?

Nevertheless, your patch looks simple and sensible, and I'm certainly
willing to apply it.  Look for a new upload soon.  Thanks very much.

-- 
Chris Waters           |  Pneumonoultra-        osis is too long
xtifr@debian.org       |  microscopicsilico-    to fit into a single
or xtifr@speakeasy.net |  volcaniconi-          standalone haiku

Message #15 received at 287360-close@bugs.debian.org (full text, mbox, reply):

From: Sergei Golovan <sgolovan@nes.ru>

To: 287360-close@bugs.debian.org

Subject: The similar patch is applied already

Date: Sun, 30 Aug 2009 20:30:52 +0400

Version: 8.4.14-1

The similar patch was applied between 8.4.12 and 8.4.14, so I'm closing the bug.

Cheers!
-- 
Sergei Golovan

Send a report that this bug log contains spam.