[83] in Zephyr_Bugs
7.1H DS3100 zwgc segfaults
daemon@ATHENA.MIT.EDU (epeisach@ATHENA.MIT.EDU)
Tue Aug 14 17:41:54 1990
From: epeisach@ATHENA.MIT.EDU
Date: Tue, 14 Aug 90 17:41:38 EDT
To: bugs@ATHENA.MIT.EDU
Cc: bug-zephyr@ATHENA.MIT.EDU
If you have absolutly no resources loaded into an X server and try
starting zwgc, it segfaults in XrmGetStringDatabase. TYhe man page
indicates that it expects a "null terminated string." As far as I can
tell, a NULL pointer is not a null terminated string and causes the
segfault. Ideally the X library should return NULL in this case, but it
doesn't. I will send a separate bug report to the Consortium suggesting
that they test for it and return null in that case. Looking at other
routines in the X library appears to make the check and fall back on a
users "~/.Xdefaults" file.
Reproduce by:
a) remotely log into a DS3100
b) Start the X server and pop up an xclock on it
c) /usr/etc/zwgc -display :0
See the nice segfault.
Ezra
Fix as follows: (will be installed shortly in the build used on the DS3100)
RCS file: RCS/X_driver.c,v
retrieving revision 1.1
diff -c -r1.1 X_driver.c
*** /tmp/,RCSt1a28975 Tue Aug 14 17:35:04 1990
--- X_driver.c Tue Aug 14 17:27:30 1990
***************
*** 274,280 ****
/*
* Get resources from the just opened display:
*/
! temp_db2 = XrmGetStringDatabase(dpy->xdefaults);
/*
* Merge the 4 sets of resources together such that when searching
--- 274,283 ----
/*
* Get resources from the just opened display:
*/
! if(dpy->xdefaults != NULL)
! temp_db2 = XrmGetStringDatabase(dpy->xdefaults);
! else
! temp_db2 = NULL;
/*
* Merge the 4 sets of resources together such that when searching
