Re: xpdf segs fault

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?


>
> 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