Re: xpdf segs fault

On Oct 31 2022, Walter Alejandro Iglesias wrote:
> On Oct 30 2022, Theo Buehler wrote:
> > On Sun, Oct 30, 2022 at 11:04:20PM +0100, Theo Buehler wrote:
> > > On Sun, Oct 30, 2022 at 09:00:53PM +0100, Walter Alejandro Iglesias wrote:
> > > > Hello,
> > > >
> > > > I suppose I have to report this bug here.
> > > >
> > > > As far as I was aware Xpdf search dialog didn't support non ascii
> > > > characters (as it also the case with mupdf). Lately I been using the
> > > > xpopple version under debian, and I realized it now lets you do utf8
> > > > searches.
> > > >
> > > > Happy with this xpdf improvement I tried to do the same under openbsd (I
> > > > assume openbsd xpdf port is not the xpopple version, right?), it let me
> > > > type some utf8 characters (spanish keyboard) in its search dialog but
> > > > when I type characters with tilde Xpdf segs fault.
> > >
> > > It's a pretty bad out-of-bounds access in motif.
>
> I understand. I've been investigating how motif handles utf8, it seems
> to be really entangled.
>
> > > The diff below makes
> > > things work for me. Searching for spanish words with accents in xpdf
> > > works for me with this diff.
>
> Your patch solves the segfault, and now I can type characters with tilde.
> But keyboard input doesn't let me enter three bytes utf8 characters, like
> mdash, quotes, ellipsis or euro sign. Is that blocked for some reason?

The issue is explained here:

https://bugs.debian.org/cgi-bin/bugreport.cgi?bug=946270

It seems motif asumes you're entering latin-1 characters even when they
are utf-8. How do you generate patches for ports? Is there a cvs
command to download the port's sources?


>
>
> >
> > Forgot one last tweak (<= vs <). This is better:
> >
> > Index: Makefile
> > ===================================================================
> > RCS file: /cvs/ports/x11/motif/Makefile,v
> > retrieving revision 1.8
> > diff -u -p -r1.8 Makefile
> > --- Makefile 11 Mar 2022 20:16:47 -0000 1.8
> > +++ Makefile 30 Oct 2022 22:00:43 -0000
> > @@ -1,6 +1,7 @@
> > COMMENT= Motif toolkit
> >
> > DISTNAME= motif-2.3.8
> > +REVISION= 0
> >
> > SHARED_LIBS += Xm 6.1 # 4.4
> > SHARED_LIBS += Mrm 4.1 # 4.4
> > Index: patches/patch-lib_Xm_VirtKeys_c
> > ===================================================================
> > RCS file: patches/patch-lib_Xm_VirtKeys_c
> > diff -N patches/patch-lib_Xm_VirtKeys_c
> > --- /dev/null 1 Jan 1970 00:00:00 -0000
> > +++ patches/patch-lib_Xm_VirtKeys_c 30 Oct 2022 22:05:54 -0000
> > @@ -0,0 +1,24 @@
> > +Check bounds before accessing the keycaps table.
> > +
> > +Index: lib/Xm/VirtKeys.c
> > +--- lib/Xm/VirtKeys.c.orig
> > ++++ lib/Xm/VirtKeys.c
> > +@@ -558,10 +558,16 @@ FindVirtKey(Display *dpy,
> > + XmDisplay xmDisplay = (XmDisplay) XmGetXmDisplay( dpy);
> > + XmVKeyBinding keyBindings = xmDisplay->display.bindings;
> > + KeyCode min_kcode;
> > +- int ks_per_kc;
> > ++ int min_kc, max_kc, ks_per_kc;
> > + KeySym *ks_table = XtGetKeysymTable( dpy, &min_kcode, &ks_per_kc);
> > + KeySym *kc_map = &ks_table[(keycode - min_kcode) * ks_per_kc];
> > +- Modifiers EffectiveSMMask = EffectiveStdModMask( dpy, kc_map, ks_per_kc);
> > ++ Modifiers EffectiveSMMask;
> > ++
> > ++ XDisplayKeycodes(dpy, &min_kc, &max_kc);
> > ++ if (keycode < min_kcode || (keycode - min_kcode) * ks_per_kc >= max_kc)
> > ++ return;
> > ++
> > ++ EffectiveSMMask = EffectiveStdModMask( dpy, kc_map, ks_per_kc);
> > +
> > + /* Get the modifiers from the actual event */
> > + Modifiers VirtualStdMods = 0;
>
> --
> Walter

--
Walter