[gtksourceview/gnome-3-24] CompletionContext: fix Coverity defect

[Sébastien Wilmet <swilmet src gnome org>]

commit 5cc67a2f2cfee3e2ccfc353fa37531dc51342e83
Author: Sébastien Wilmet <swilmet gnome org>
Date:   Sun Jan 22 11:52:41 2017 +0100

    CompletionContext: fix Coverity defect
    
    It's indeed better to check the return value of
    gtk_source_completion_context_get_iter().
    
    I suppose that the GValue returns a "NULL" value if it is not set.

 gtksourceview/gtksourcecompletioncontext.c |    7 +++++--
 1 files changed, 5 insertions(+), 2 deletions(-)
---
diff --git a/gtksourceview/gtksourcecompletioncontext.c b/gtksourceview/gtksourcecompletioncontext.c
index bede988..9aa6c7d 100644
--- a/gtksourceview/gtksourcecompletioncontext.c
+++ b/gtksourceview/gtksourcecompletioncontext.c
@@ -197,8 +197,11 @@ gtk_source_completion_context_get_property (GObject    *object,
                case PROP_ITER:
                        {
                                GtkTextIter iter;
-                               gtk_source_completion_context_get_iter (context, &iter);
-                               g_value_set_boxed (value, &iter);
+
+                               if (gtk_source_completion_context_get_iter (context, &iter))
+                               {
+                                       g_value_set_boxed (value, &iter);
+                               }
                        }
                        break;