[gimp] Issue #1748 - Crash when parsing currupt tool preset

[Michael Natterer <mitch src gnome org>]

commit e27e783f8836ca44ffd17d4c5190244dd024eb55
Author: Michael Natterer <mitch gimp org>
Date:   Wed Jul 4 01:52:19 2018 +0200

    Issue #1748 - Crash when parsing currupt tool preset
    
    Bail out with an error instead of crashing when the tool options type
    name is empty.

 app/core/gimptoolpreset.c | 8 ++++++++
 1 file changed, 8 insertions(+)
---
diff --git a/app/core/gimptoolpreset.c b/app/core/gimptoolpreset.c
index 8558850a4d..94083c0915 100644
--- a/app/core/gimptoolpreset.c
+++ b/app/core/gimptoolpreset.c
@@ -390,6 +390,14 @@ gimp_tool_preset_deserialize_property (GimpConfig *config,
             break;
           }
 
+        if (! (type_name && *type_name))
+          {
+            g_scanner_error (scanner, "GimpToolOptions type name is empty");
+            *expected = G_TOKEN_NONE;
+            g_free (type_name);
+            break;
+          }
+
         if (! strcmp (type_name, "GimpTransformOptions"))
           {
             g_printerr ("Correcting tool options type GimpTransformOptions "