[gnome-builder] meson: check for meson in test provider

[Christian Hergert <chergert src gnome org>]

commit aa6c602a92dd360662dd8a63c5cf2404c7e677a1
Author: Christian Hergert <chergert redhat com>
Date:   Mon Dec 18 00:23:17 2017 -0800

    meson: check for meson in test provider
    
    If we don't have a meson project, the test provider shouldn't
    try to do anything.

 src/plugins/meson/gbp-meson-test-provider.c |   11 ++++++++++-
 1 files changed, 10 insertions(+), 1 deletions(-)
---
diff --git a/src/plugins/meson/gbp-meson-test-provider.c b/src/plugins/meson/gbp-meson-test-provider.c
index 5a33a45..e9b7dd1 100644
--- a/src/plugins/meson/gbp-meson-test-provider.c
+++ b/src/plugins/meson/gbp-meson-test-provider.c
@@ -20,6 +20,7 @@
 
 #include <json-glib/json-glib.h>
 
+#include "gbp-meson-build-system.h"
 #include "gbp-meson-test.h"
 #include "gbp-meson-test-provider.h"
 
@@ -261,6 +262,7 @@ gbp_meson_test_provider_reload (gpointer user_data)
   GbpMesonTestProvider *self = user_data;
   IdeBuildPipeline *pipeline;
   IdeBuildManager *build_manager;
+  IdeBuildSystem *build_system;
   IdeContext *context;
 
   IDE_ENTRY;
@@ -274,10 +276,17 @@ gbp_meson_test_provider_reload (gpointer user_data)
   g_clear_object (&self->build_cancellable);
 
   /*
+   * Check that we're working with a meson build system.
+   */
+  context = ide_object_get_context (IDE_OBJECT (self));
+  build_system = ide_context_get_build_system (context);
+  if (build_system == NULL)
+    IDE_RETURN (G_SOURCE_REMOVE);
+
+  /*
    * Get access to the pipeline so we can create a launcher to
    * introspect meson from within the build environment.
    */
-  context = ide_object_get_context (IDE_OBJECT (self));
   build_manager = ide_context_get_build_manager (context);
   pipeline = ide_build_manager_get_pipeline (build_manager);
   if (pipeline == NULL)