Re: [hackers] [st] [PATCHv2] Work around BadLength error by disallowing color fonts
On Tue, 23 Apr 2019 22:08:30 +0200
"Silvan Jegen" wrote:
Dear Silvan,
> From what I can tell, returning 1 in this case won't work because st
> calls die() when xloadfont returns non-0 at all call sites. We would
> have to load a fallback font instead, I think.
the failure case here is a result of bad user input (as the user
specified a font string that contains a colour font), but I agree that
this is better moved one level up so we can error out and say "better
not specify colour fonts, as it leads to crashes easily), at least
print a warn() or something, but I just kept a die() here.
> The dwm patch for for this issue [0] also adds this call to choose the
> fallback font.
>
> + FcPatternAddBool(fcpattern, FC_COLOR, FcFalse);
>
> We probably have to do the same in st.
This is a really good point! See attached version 2 of my patch
reflecting your suggestions.
With best regards
Laslo
--
Laslo Hunhold
>From 9aad206ca079fb556e916304cd2249384a6485fb Mon Sep 17 00:00:00 2001
From: Laslo Hunhold
Date: Tue, 23 Apr 2019 10:02:14 +0200
Subject: [PATCH] Work around BadLength error by disallowing color fonts
This problem has given us enough trouble on the ML alone and is a
bug in the Xft library that probably won't ever be fixed.
This change is a port of Anselm's commit to dwm
(cb3f58ad06993f7ef3a7d8f61468012e2b786cab) and with input
from Silvan Jegen.
---
LICENSE | 4 ++--
x.c | 13 +
2 files changed, 15 insertions(+), 2 deletions(-)
diff --git a/LICENSE b/LICENSE
index c356c39..07518e3 100644
--- a/LICENSE
+++ b/LICENSE
@@ -4,7 +4,7 @@ MIT/X Consortium License
© 2018 Devin J. Pohly
© 2014-2017 Quentin Rameau
© 2009-2012 Aurélien APTEL
-© 2008-2017 Anselm R Garbe
+© 2008-2019 Anselm R Garbe
© 2012-2017 Roberto E. Vargas Caballero
© 2012-2016 Christoph Lohmann <20h at r-36 dot net>
© 2013 Eon S. Jeon
@@ -13,7 +13,7 @@ MIT/X Consortium License
© 2013-2014 Eric Pruitt
© 2013 Michael Forney
© 2013-2014 Markus Teich
-© 2014-2015 Laslo Hunhold
+© 2014-2019 Laslo Hunhold
Permission is hereby granted, free of charge, to any person obtaining a
copy of this software and associated documentation files (the "Software"),
diff --git a/x.c b/x.c
index 5828a3b..a3347d4 100644
--- a/x.c
+++ b/x.c
@@ -910,6 +910,7 @@ xloadfont(Font *f, FcPattern *pattern)
void
xloadfonts(char *fontstr, double fontsize)
{
+ FcBool iscol;
FcPattern *pattern;
double fontval;
@@ -944,6 +945,17 @@ xloadfonts(char *fontstr, double fontsize)
defaultfontsize = usedfontsize;
}
+ /* Do not allow using color fonts. This is a workaround for a BadLength
+ * error from Xft with color glyphs. Modelled on the Xterm workaround. See
+ * https://bugzilla.redhat.com/show_bug.cgi?id=1498269
+ * https://lists.suckless.org/dev/1701/30932.html
+ * https://bugs.debian.org/cgi-bin/bugreport.cgi?bug=916349
+ * and lots more all over the internet.
+ */
+ if(FcPatternGetBool(pattern, FC_COLOR, 0, ) == FcResultMatch && iscol) {
+ die("Xft causes crashes with color fonts like '%s'\n", fontstr);
+ }
+
if (xloadfont(, pattern))
die("can't open font %s\n", fontstr);
@@ -1235,6 +1247,7 @@ xmakeglyphfontspecs(XftGlyphFontSpec *specs, const Glyph *glyphs, int len, int x
FcPatternAddCharSet(fcpattern, FC_CHARSET,
fccharset);
FcPatternAddBool(fcpattern, FC_SCALABLE, 1);
+ FcPatternAddBool(fcpattern, FC_COLOR, 0);
FcConfigSubstitute(0, fcpattern,
FcMatchPattern);
--
2.21.0
pgpbNfyDrHRem.pgp
Description: PGP signature
Re: [hackers] [st] [PATCH] Work around BadLength error by disallowing color fonts
Hi Laslo
Thanks for giving this a shot!
A comment below.
Laslo Hunhold wrote:
> Dear fellow hackers,
>
> this patch will hopefully resolve the many mails we get on dev@ and
> hackers@ regarding crashes of st due to emoji-fonts triggering some
> voodoo-condition in Xft.
>
> I hope my port of Anselm's change to dwm to st is correct and would
> love to hear feedback.
>
> With best regards
>
> Laslo Hunhold
>
> [...]
>
> diff --git a/x.c b/x.c
> index 5828a3b..074df47 100644
> --- a/x.c
> +++ b/x.c
> @@ -837,12 +837,24 @@ xgeommasktogravity(int mask)
> int
> xloadfont(Font *f, FcPattern *pattern)
> {
> + FcBool iscol;
> FcPattern *configured;
> FcPattern *match;
> FcResult result;
> XGlyphInfo extents;
> int wantattr, haveattr;
>
> + /* Do not allow using color fonts. This is a workaround for a
> BadLength
> +* error from Xft with color glyphs. Modelled on the Xterm
> workaround. See
> +* https://bugzilla.redhat.com/show_bug.cgi?id=1498269
> +* https://lists.suckless.org/dev/1701/30932.html
> +* https://bugs.debian.org/cgi-bin/bugreport.cgi?bug=916349
> +* and lots more all over the internet.
> +*/
> + if(FcPatternGetBool(pattern, FC_COLOR, 0, ) == FcResultMatch &&
> iscol) {
> + return 1;
> + }
> +
From what I can tell, returning 1 in this case won't work because st
calls die() when xloadfont returns non-0 at all call sites. We would
have to load a fallback font instead, I think.
The dwm patch for for this issue [0] also adds this call to choose the
fallback font.
+ FcPatternAddBool(fcpattern, FC_COLOR, FcFalse);
We probably have to do the same in st.
Cheers,
Silvan
[0]
https://git.suckless.org/libsl/commit/53ebcb48c6b12882c6dbe352ee43c96b2fb01b84.html
[hackers] [st] [PATCH] Work around BadLength error by disallowing color fonts
Dear fellow hackers,
this patch will hopefully resolve the many mails we get on dev@ and
hackers@ regarding crashes of st due to emoji-fonts triggering some
voodoo-condition in Xft.
I hope my port of Anselm's change to dwm to st is correct and would
love to hear feedback.
With best regards
Laslo Hunhold
--
Laslo Hunhold
>From 69cfb2193f5e7bb8dda42b3dc5474e3d04170ad1 Mon Sep 17 00:00:00 2001
From: Laslo Hunhold
Date: Tue, 23 Apr 2019 10:02:14 +0200
Subject: [PATCH] Work around BadLength error by disallowing color fonts
This problem has given us enough trouble on the ML alone and is a
bug in the Xft library that probably won't ever be fixed.
This change is a port of Anselm's commit to dwm
(cb3f58ad06993f7ef3a7d8f61468012e2b786cab).
---
LICENSE | 4 ++--
x.c | 12
2 files changed, 14 insertions(+), 2 deletions(-)
diff --git a/LICENSE b/LICENSE
index c356c39..07518e3 100644
--- a/LICENSE
+++ b/LICENSE
@@ -4,7 +4,7 @@ MIT/X Consortium License
© 2018 Devin J. Pohly
© 2014-2017 Quentin Rameau
© 2009-2012 Aurélien APTEL
-© 2008-2017 Anselm R Garbe
+© 2008-2019 Anselm R Garbe
© 2012-2017 Roberto E. Vargas Caballero
© 2012-2016 Christoph Lohmann <20h at r-36 dot net>
© 2013 Eon S. Jeon
@@ -13,7 +13,7 @@ MIT/X Consortium License
© 2013-2014 Eric Pruitt
© 2013 Michael Forney
© 2013-2014 Markus Teich
-© 2014-2015 Laslo Hunhold
+© 2014-2019 Laslo Hunhold
Permission is hereby granted, free of charge, to any person obtaining a
copy of this software and associated documentation files (the "Software"),
diff --git a/x.c b/x.c
index 5828a3b..074df47 100644
--- a/x.c
+++ b/x.c
@@ -837,12 +837,24 @@ xgeommasktogravity(int mask)
int
xloadfont(Font *f, FcPattern *pattern)
{
+ FcBool iscol;
FcPattern *configured;
FcPattern *match;
FcResult result;
XGlyphInfo extents;
int wantattr, haveattr;
+ /* Do not allow using color fonts. This is a workaround for a BadLength
+ * error from Xft with color glyphs. Modelled on the Xterm workaround. See
+ * https://bugzilla.redhat.com/show_bug.cgi?id=1498269
+ * https://lists.suckless.org/dev/1701/30932.html
+ * https://bugs.debian.org/cgi-bin/bugreport.cgi?bug=916349
+ * and lots more all over the internet.
+ */
+ if(FcPatternGetBool(pattern, FC_COLOR, 0, ) == FcResultMatch && iscol) {
+ return 1;
+ }
+
/*
* Manually configure instead of calling XftMatchFont
* so that we can use the configured pattern for
--
2.21.0
pgphRfiDcoPen.pgp
Description: PGP signature
