Add a safety precausion

diff --git a/simgear/screen/extensions.cxx b/simgear/screen/extensions.cxx
index 99a170866c2b38819139b922f8dcd809dda7070b..c16509f6fabe24e632f67727f6f3c52eda31a41b 100644 (file)
--- a/simgear/screen/extensions.cxx
+++ b/simgear/screen/extensions.cxx
@@ -33,6 +33,9 @@ bool SGSearchExtensionsString(char *extString, char *extName) {
     char *p, *end;
     int n, extNameLen;
 
+    if ((extString == NULL) || (extName == NULL))
+        return false;
+
     extNameLen = strlen(extName);
 
     p=extString;