[gtk/for-master] rendernodeparser: Handle Cairo being stupid

[Benjamin Otte <otte src gnome org>]

commit d81cf5a44345cc8a8d3bd53501dbb24f96d17a21
Author: Benjamin Otte <otte redhat com>
Date:   Mon Jun 3 17:20:59 2019 +0200

    rendernodeparser: Handle Cairo being stupid
    
    Cairo writes to finished streams, so we have to make sure to keep the
    stream around to allow it to do that.

 gsk/gskrendernodeparser.c | 21 +++++++++++++++++----
 1 file changed, 17 insertions(+), 4 deletions(-)
---
diff --git a/gsk/gskrendernodeparser.c b/gsk/gskrendernodeparser.c
index 4cdf70f630..2b35dc7cb2 100644
--- a/gsk/gskrendernodeparser.c
+++ b/gsk/gskrendernodeparser.c
@@ -1902,6 +1902,12 @@ cairo_write_array (void                *closure,
   return CAIRO_STATUS_SUCCESS;
 }
 
+static void
+cairo_destroy_array (gpointer array)
+{
+  g_byte_array_free (array, TRUE);
+}
+
 static void
 render_node_print (Printer       *p,
                    GskRenderNode *node)
@@ -2394,6 +2400,7 @@ render_node_print (Printer       *p,
 #ifdef CAIRO_HAS_SCRIPT_SURFACE
             if (cairo_surface_get_type (surface) == CAIRO_SURFACE_TYPE_RECORDING)
               {
+                static const cairo_user_data_key_t cairo_is_stupid_key;
                 cairo_device_t *script;
 
                 array = g_byte_array_new ();
@@ -2407,11 +2414,17 @@ render_node_print (Printer       *p,
                     g_free (b64);
                   }
 
-              cairo_device_destroy (script);
-              g_byte_array_free (array, TRUE);
-            }
+                /* because Cairo is stupid and writes to the device after we finished it,
+                 * we can't just
+                g_byte_array_free (array, TRUE);
+                 * but have to
+                 */
+                g_byte_array_set_size (array, 0);
+                cairo_device_set_user_data (script, &cairo_is_stupid_key, array, cairo_destroy_array);
+                cairo_device_destroy (script);
+              }
 #endif
-        }
+          }
 
         end_node (p);
       }