Re: [MacPorts] #52605: adwaita-icon-theme @3.22.0 fails building on 10.5.8 PPC

16 Oct 2016

      #52605: adwaita-icon-theme @3.22.0 fails building on 10.5.8 PPC
---------------------------------+----------------------
  Reporter:  braumann@…          |      Owner:  devans@…
      Type:  defect              |     Status:  assigned
  Priority:  Normal              |  Milestone:
 Component:  ports               |    Version:  2.3.4
Resolution:                      |   Keywords:
      Port:  adwaita-icon-theme  |
---------------------------------+----------------------

Comment (by devans@…):

 While you were testing, I looked into the `gtk-encode-symbolic-svg` code.
 This utility converts svg icon files to specially encoded png files that
 have many of the properties (color substitution, for example) as svg but
 with much less processing overhead.

 `gtk-encode-symbolic-svg` uses the following code to read the svg into an
 in-memory GdkPixbuf:
 {{{
       loaded = load_symbolic_svg (file_data, file_len, width, height,
                                   &g,
                                   plane == 0 ? &r : &g,
                                   plane == 1 ? &r : &g,
                                   plane == 2 ? &r : &g,
                                   error);
       if (loaded == NULL)
         return NULL;
 }}}

 and `load_symbolic_svg` uses the following code to do the work

 {{{
   stream = g_memory_input_stream_new_from_data (data, -1, g_free);
   pixbuf = gdk_pixbuf_new_from_stream_at_scale (stream,
                                                 width,
                                                 height,
                                                 TRUE,
                                                 NULL,
                                                 error);

 }}}

 Error handling here is what I would call "minimum magnificent"! If
 gdk_pixbuf_new_from_stream_at_scale returns an error it is propagated
 upstream without checks to the main caller which then prints the message
 we're seeing if an error is set without check which error it is.  Possible
 errors are those in the GDK_PIXBUF_ERROR domain
 {{{
 GDK_PIXBUF_ERROR_CORRUPT_IMAGE         An image file was broken somehow.
 GDK_PIXBUF_ERROR_INSUFFICIENT_MEMORY   Not enough memory.
 GDK_PIXBUF_ERROR_BAD_OPTION            A bad option was passed to a pixbuf
 save module.
 GDK_PIXBUF_ERROR_UNKNOWN_TYPE          Unknown image type.
 GDK_PIXBUF_ERROR_UNSUPPORTED_OPERATION Don't know how to perform the given
 operation on the type of image at hand.
 GDK_PIXBUF_ERROR_FAILED                Generic failure code, something
 went wrong.
 GDK_PIXBUF_ERROR_INCOMPLETE_ANIMATION  Only part of the animation was
 loaded.
 }}}

 and in the G_IO_ERROR domain (too many to list here) but some sort of GIO
 stream error is a possibility.

 Lots of possibilities.

 Can you run `gtk-encode-symbolic-svg` under gdb with a breakpoint at
 `load_symbolic_svg` and step from there to see what error is really being
 returned?

 To do this sensibly, one would need to build at least gtk3 and gdk-pixbuf2
 with debugging symbols enabled and without cleaning after the build so
 that the source code is still available for reference.  You can do this
 using the following commands:
 {{{
 sudo port -nsk upgrade --force gdk-pixbuf2 'configure.optflags='-g -O0'
 sudo port -nsk upgrade --force gtk3 'configure.optflags='-g -O0'
 }}}

 So the question is: what is what error is being returned by
 `load_symbolic_svg`?

-- 
Ticket URL: <https://trac.macports.org/ticket/52605#comment:19>
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