[gegl] bin: avoid an use after free in completion engine

[Øyvind "pippin" Kolås <ok src gnome org>]

commit a51256eb1c2b764a89d00fd61dedb64c3fbd32f9
Author: Øyvind Kolås <pippin gimp org>
Date:   Tue Jul 16 12:52:12 2019 +0200

    bin: avoid an use after free in completion engine

 bin/ui-core.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)
---
diff --git a/bin/ui-core.c b/bin/ui-core.c
index 3a289e83e..7436986b7 100644
--- a/bin/ui-core.c
+++ b/bin/ui-core.c
@@ -4813,7 +4813,7 @@ static GList *commandline_get_completions (GeglNode *node,
     char *tmp = g_strdup (commandline);
     char *fragment;
     char ** operations;
-    char *found_op = NULL;
+    const char *found_op = NULL;
     gint i;
     guint n_operations;
     /* the last fragment is what we're completing */
@@ -4839,7 +4839,7 @@ static GList *commandline_get_completions (GeglNode *node,
         if (!strcmp (operations[i], fragment) ||
             !strcmp (operations[i], prefixed_by_gegl))
           {
-            found_op = operations[i];
+            found_op = g_intern_string (operations[i]);
           }
       }