[glib: 1/2] gresource: Document the `to-pixdata` option as being deprecated

[Philip Withnall <pwithnall src gnome org>]

commit b63e9889a8a72c4f2f8717dcd94994bce9ccc9f8
Author: Philip Withnall <pwithnall endlessos org>
Date:   Tue Dec 22 18:42:05 2020 +0000

    gresource: Document the `to-pixdata` option as being deprecated
    
    Just embed a PNG instead. gdk-pixbuf deprecated its pixdata support in
    version 2.32, in 2015.
    
    Signed-off-by: Philip Withnall <pwithnall endlessos org>
    
    Fixes: #1281

 docs/reference/gio/glib-compile-resources.xml |  3 +++
 gio/gresource.c                               | 16 ++++++++++------
 2 files changed, 13 insertions(+), 6 deletions(-)
---
diff --git a/docs/reference/gio/glib-compile-resources.xml b/docs/reference/gio/glib-compile-resources.xml
index 5421f3d91..a85f6003c 100644
--- a/docs/reference/gio/glib-compile-resources.xml
+++ b/docs/reference/gio/glib-compile-resources.xml
@@ -219,6 +219,9 @@ searched for in the <envar>PATH</envar>.
 <varlistentry>
 <term><envar>GDK_PIXBUF_PIXDATA</envar></term>
 <listitem><para>
+Deprecated since gdk-pixbuf 2.32, as <type>GResource</type> supports embedding
+modern image formats without conversion.
+</para><para>
 The full path to the <command>gdk-pixbuf-pixdata</command> executable. This is
 used to preprocess resources with the <literal>to-pixdata</literal> preprocessing
 option. If this environment variable is not set, <command>gdk-pixbuf-pixdata</command>
diff --git a/gio/gresource.c b/gio/gresource.c
index b495d12ac..3d3304063 100644
--- a/gio/gresource.c
+++ b/gio/gresource.c
@@ -76,12 +76,16 @@ G_DEFINE_BOXED_TYPE (GResource, g_resource, g_resource_ref, g_resource_unref)
  * the xmllint executable, or xmllint must be in the `PATH`; otherwise
  * the preprocessing step is skipped.
  *
- * `to-pixdata` which will use the gdk-pixbuf-pixdata command to convert
- * images to the GdkPixdata format, which allows you to create pixbufs directly using the data inside
- * the resource file, rather than an (uncompressed) copy of it. For this, the gdk-pixbuf-pixdata
- * program must be in the PATH, or the `GDK_PIXBUF_PIXDATA` environment variable must be
- * set to the full path to the gdk-pixbuf-pixdata executable; otherwise the resource compiler will
- * abort.
+ * `to-pixdata` (deprecated since gdk-pixbuf 2.32) which will use the
+ * `gdk-pixbuf-pixdata` command to convert images to the #GdkPixdata format,
+ * which allows you to create pixbufs directly using the data inside the
+ * resource file, rather than an (uncompressed) copy of it. For this, the
+ * `gdk-pixbuf-pixdata` program must be in the `PATH`, or the
+ * `GDK_PIXBUF_PIXDATA` environment variable must be set to the full path to the
+ * `gdk-pixbuf-pixdata` executable; otherwise the resource compiler will abort.
+ * `to-pixdata` has been deprecated since gdk-pixbuf 2.32, as #GResource
+ * supports embedding modern image formats just as well. Instead of using it,
+ * embed a PNG or SVG file in your #GResource.
  *
  * `json-stripblanks` which will use the `json-glib-format` command to strip
  * ignorable whitespace from the JSON file. For this to work, the