[gimp] Prevent possible crash when loading file with scheme_load_file. From SVN version 101 of offical vers

[Kevin Cozens <kcozens src gnome org>]

commit ac45213ccd4572fa453de0b37c812a68035ee19b
Author: Kevin Cozens <kevin ve3syb ca>
Date:   Sun Aug 17 18:06:03 2014 -0400

    Prevent possible crash when loading file with scheme_load_file.
    From SVN version 101 of offical version of TinyScheme.

 plug-ins/script-fu/tinyscheme/scheme.c |    2 ++
 1 files changed, 2 insertions(+), 0 deletions(-)
---
diff --git a/plug-ins/script-fu/tinyscheme/scheme.c b/plug-ins/script-fu/tinyscheme/scheme.c
index fc47880..f14de9d 100644
--- a/plug-ins/script-fu/tinyscheme/scheme.c
+++ b/plug-ins/script-fu/tinyscheme/scheme.c
@@ -5114,6 +5114,8 @@ void scheme_load_named_file(scheme *sc, FILE *fin, const char *filename) {
   sc->load_stack[0].rep.stdio.curr_line = 0;
   if(fin!=stdin && filename)
     sc->load_stack[0].rep.stdio.filename = store_string(sc, strlen(filename), filename, 0);
+  else
+    sc->load_stack[0].rep.stdio.filename = NULL;
 #endif
 
   sc->inport=sc->loadport;