[gegl] tools/introspect: harden escape() against NULL strings

[Nils Philippsen <nphilipp src gnome org>]

commit fefceae946d50c2579147fd4aa207830b54db69c
Author: Nils Philippsen <nils redhat com>
Date:   Wed Mar 21 13:00:50 2012 +0100

    tools/introspect: harden escape() against NULL strings
    
    This can happen e.g. if the blurb of a property is NULL.

 tools/introspect.c |    2 +-
 1 files changed, 1 insertions(+), 1 deletions(-)
---
diff --git a/tools/introspect.c b/tools/introspect.c
index 2fcb86c..7e4eab3 100644
--- a/tools/introspect.c
+++ b/tools/introspect.c
@@ -55,7 +55,7 @@ static gchar *escape (const gchar *string)
   const gchar *p=string;
   gint i=0;
 
-  while (*p)
+  while (p && *p)
     {
       switch (*p)
         {