[gnome-builder] build: check for error

[Christian Hergert <chergert src gnome org>]

commit e4f930ececb9e65465215ba5bedc50684a53ca7d
Author: Christian Hergert <chergert redhat com>
Date:   Tue May 10 14:53:51 2016 +0300

    build: check for error
    
    While our g_error_matches() call is safe from dereferences, we immediately
    dereference right after. So we still need the check.

 plugins/build-tools/gbp-build-workbench-addin.c |    2 +-
 1 files changed, 1 insertions(+), 1 deletions(-)
---
diff --git a/plugins/build-tools/gbp-build-workbench-addin.c b/plugins/build-tools/gbp-build-workbench-addin.c
index d7f2d14..51b1b3d 100644
--- a/plugins/build-tools/gbp-build-workbench-addin.c
+++ b/plugins/build-tools/gbp-build-workbench-addin.c
@@ -83,7 +83,7 @@ gbp_build_workbench_addin_build_cb (GObject      *object,
 
   build_result = ide_builder_build_finish (builder, result, &error);
 
-  if (!g_error_matches (error, G_IO_ERROR, G_IO_ERROR_CANCELLED))
+  if (error != NULL && !g_error_matches (error, G_IO_ERROR, G_IO_ERROR_CANCELLED))
     g_message ("%s", error->message);
 }