flatpak: Sync with Flathub

This reverts commit f63e13ed39.

This workaround does not work, since GStreamer build manifest we use
as shared module from Flathub has explicitly enabled libmpeg2 support.

src/bin/clapper-app/clapper-app-utils.c

@@ -582,7 +582,7 @@ _create_pipeline_svg_file_in_thread (GTask *task, GObject *source G_GNUC_UNUSED,
   GVC_t *gvc;
   gchar *path, *template = NULL, *dot_data = NULL, *img_data = NULL;
   gint fd;
-  guint size = 0;
+  gsize size = 0;
 
   if (!(tmp_subdir = _create_tmp_subdir ("pipelines", cancellable, &error)))
     goto finish;
@@ -610,7 +610,16 @@ _create_pipeline_svg_file_in_thread (GTask *task, GObject *source G_GNUC_UNUSED,
 
   gvc = gvContext ();
   gvLayout (gvc, graph, "dot");
+
+#ifdef HAVE_GVC_13
   gvRenderData (gvc, graph, "svg", &img_data, &size);
+#else
+  {
+    guint tmp_size = 0; // Temporary uint to satisfy older API
+    gvRenderData (gvc, graph, "svg", &img_data, &tmp_size);
+    size = tmp_size;
+  }
+#endif
 
   agclose (graph);
   gvFreeContext (gvc);

src/bin/clapper-app/meson.build

@@ -105,6 +105,9 @@ if not pp_option.disabled()
   if cgraph_dep.found() and gvc_dep.found()
     clapperapp_c_args += ['-DHAVE_GRAPHVIZ']
     clapperapp_deps += [cgraph_dep, gvc_dep]
+    if gvc_dep.version().version_compare('>= 13.0.0')
+      clapperapp_c_args += ['-DHAVE_GVC_13']
+    endif
     clapperapp_available_functionalities += 'pipeline-preview'
   elif pp_option.enabled()
     error('pipeline-preview option was enabled, but required dependencies were not found')