[Buildroot] [PATCH 1/1] Allow imagemagick to find ghostscript fonts.

[Ricardo Martincoski]

Hello all,

I don't need this patch for my own personal use, but I took a look into it.

On Tue, 29 Dec 2015 17:45:04 +0100, Thomas Petazzoni wrote:
> Could you give a specific example use of imagemagick that triggers this
> problem, so that we can reproduce the problem on our side and
> investigate the possible solutions?

Using this config with the master branch:
BR2_PACKAGE_IMAGEMAGICK=y  
BR2_PACKAGE_GHOSTSCRIPT_FONTS=y
BR2_PACKAGE_FREETYPE=y
The problem can be triggered by converting any text file to ps
$ cd /tmp ; echo -e 'text 1\ntext 2' > file.txt ; convert file.txt file.ps

And doing this on the target works around the problem
$ sed -e s,/usr/share/fonts/type1/gsfonts,/usr/share/fonts/gs,g -i /etc/ImageMagick-6/type-ghostscript.xml


On Tue Jun 16 20:01:02 UTC 2015, Baruch Siach wrote:
>On Tue, Jun 16, 2015 at 02:27:23PM -0400, grepper wrote:
>> On 15/06/15 11:39 PM, Baruch Siach wrote:
>> > On Mon, Jun 15, 2015 at 10:12:26PM -0400, grepper wrote:
>> >> From: Robert Sohn <grepper at gmail.com>
>> >>
>> >> It appears that Imagemagick needs to be configured with
>> >>  --with-gs-font-dir=/usr/share/fonts/gs else it will not find
>> >> the ghostscript fonts and /etc/ImageMagick-6/type-ghostscript.xml
>> >> will contain the wrong font paths. You end up with messages like:

The wrong path is the default for debian-based distros
/usr/share/fonts/type1/gsfonts/ # debian non-x11, default for imagemagick
/usr/share/fonts/X11/Type1/     # debian x11

An alternative solution would be to have the fonts installed to this location
+++ b/package/ghostscript-fonts/ghostscript-fonts.mk
@@@ -13,1 -13,1 +13,1 @@@ GHOSTSCRIPT_FONTS_LICENSE_FILES = COPYI
--GHOSTSCRIPT_FONTS_TARGET_DIR = $(TARGET_DIR)/usr/share/fonts/gs
++GHOSTSCRIPT_FONTS_TARGET_DIR = $(TARGET_DIR)/usr/share/fonts/type1/gsfonts

I don't see from
grep -w '\(gs\|ghostscript-fonts\|GHOSTSCRIPT_FONTS_\)' -R package/
any explicit use of this path nor hard dependency.
But changing it can potentially break packages (in runtime!) if them expect
the fonts to be installed in the current location.

Does anyone know an example of package that would break?

>> >> Magick: unable to read font `(null)' @ error/annotate.c/RenderFreetype/1153
>> >> They are non-fatal but could get annoying fast if you are using 'convert'

The error is non-fatal in a batch conversion.
But each error means a file failed to be converted.
The output is not generated for the failed file.

>> >> on a lot of files.
>> >>
>> >> Signed-off-by: Robert Sohn <grepper at gmail.com>
>> >> ---
>> >>  package/imagemagick/imagemagick.mk | 3 ++-
>> >>  1 file changed, 2 insertions(+), 1 deletion(-)
>> >>
>> >> diff --git a/package/imagemagick/imagemagick.mk b/package/imagemagick/imagemagick.mk
>> >> index 298d0a8..1abb2a8 100644
>> >> --- a/package/imagemagick/imagemagick.mk
>> >> +++ b/package/imagemagick/imagemagick.mk
>> >> @@ -33,7 +33,8 @@ IMAGEMAGICK_CONF_OPTS = \
>> >>  	--without-dps \
>> >>  	--without-gslib \
>> >>  	--without-fpx \
>> >> -	--without-x
>> >> +	--without-x \
>> >> +	--with-gs-font-dir=/usr/share/fonts/gs

Configuring unconditionally does not seem so bad in this case, IMO.
The configured path will be added to an XML that will be used at runtime.
If freetype support is not compiled in or the fonts are not installed,
/convert/ would fail anyway.

>> > 
>> > These fonts are only available when the ghostscript-fonts is built, isn't it? 

Yes.

>> > If so, then this should be
>> > 
>> > ifeq ($(BR2_PACKAGE_GHOSTSCRIPT_FONTS),y)
>> > IMAGEMAGICK_CONF_OPTS += --with-gs-font-dir=/usr/share/fonts/gs
>> > endif

BR2_PACKAGE_FREETYPE is also needed.

>> > 
>> > Or maybe we should use $(GHOSTSCRIPT_FONTS_TARGET_DIR) here, instead of 
>> > duplicating it?

It seems good practice to me.
But we can't use GHOSTSCRIPT_FONTS_TARGET_DIR as is, it is prefixed with
TARGET_DIR. We could create an auxiliary symbol

+++ b/package/ghostscript-fonts/ghostscript-fonts.mk
@@@ -13,1 -13,1 +13,2 @@@ GHOSTSCRIPT_FONTS_LICENSE_FILES = COPYI
--GHOSTSCRIPT_FONTS_TARGET_DIR = $(TARGET_DIR)/usr/share/fonts/gs
++GHOSTSCRIPT_FONTS_DIR = /usr/share/fonts/gs
++GHOSTSCRIPT_FONTS_TARGET_DIR = $(TARGET_DIR)/$(GHOSTSCRIPT_FONTS_DIR)
+++ b/package/imagemagick/imagemagick.mk
@@@ -37,1 -37,1 +37,1 @@@ IMAGEMAGICK_CONF_OPTS = 
--	--with-gs-font-dir=/usr/share/fonts/gs
++	--with-gs-font-dir=$(GHOSTSCRIPT_FONTS_DIR)

>> 
>> Hm, the problem is that the issue will remain if ghostscript-fonts are
>> not installed. I don't know the solution to that.
>
>The usual way to set a dependency package is to add a 'select' statement for 
>that package in Config.in. In this case ghostscript-fonts is not a hard 
>dependency, because imagemagick is quite functional without it, and its size 
>is non negligible. Maybe adding a comment to the help text in Config.in would 
>suffice.
>
>What do others think?

Adding a comment to the Config.in sounds reasonable to me.
One would need both BR2_PACKAGE_FREETYPE as optional build dependency and
BR2_PACKAGE_GHOSTSCRIPT_FONTS as optional runtime dependency to get the
conversion txt -> ps to work.

Regards,
Ricardo