Relay-Version: version B 2.10 5/3/83; site utzoo.UUCP Path: utzoo!mnetor!uunet!seismo!rutgers!ucla-cs!zen!ucbvax!decvax!decwrl!sun!gorodish!guy From: guy%gorodish@Sun.COM (Guy Harris) Newsgroups: comp.windows.x Subject: Re: Fixes to paint and xedit in V11.2 Message-ID: <24248@sun.uucp> Date: Mon, 27-Jul-87 15:25:49 EDT Article-I.D.: sun.24248 Posted: Mon Jul 27 15:25:49 1987 Date-Received: Tue, 28-Jul-87 07:32:17 EDT References: <4477@jade.BERKELEY.EDU> <7439@diamond.BBN.COM> Sender: news@sun.uucp Lines: 26 > I fixed the toolkit by replacing all the calls to the various string > functions with versions called XtStrCmp, XtStrCpy, etc. that handle > NULL pointer arguments as would a VAX. More correctly, as certain C and operating-system implementations do on a VAX. Unless the VMS versions of those routines waste time checking for NULL arguments beforehand, they will blow up too, since by default VMS does not map location 0 into a process' address space. Furthermore, there are VAX UNIX implementations that permit you to take location 0 out of a process' address space; the paging System V implementations do, and John Bruner has made changes to 4BSD to permit it to as well. If somebody wants to link their programs on such a system with the "disallow null pointer references" option, they're going to be screwed unless the toolkit is fixed. Not only that, but the Berkeley people may very well decide to make no-page-0 the default if they rewrite the VM system in some future release. If the people doing X development intend to continue doing it on VAXes running 4BSD, they are hereby advised to try to get a hold of John Bruner's changes, put them into their OS, and link *all* their programs with the "no page 0" option, and catch more of these problems before the software goes out the door. Guy Harris {ihnp4, decvax, seismo, decwrl, ...}!sun!guy s tr329idssh