Fixed Win95 crash when getenv("DISPLAY") returned NULL ptr.

git-svn-id: https://svn.code.sf.net/p/freeglut/code/trunk@39 7f0cb862-5218-0410-a997-914c9d46530a

freeglut/freeglut/freeglut-1.3/freeglut_init.c

@@ -366,6 +366,11 @@ void FGAPIENTRY glutInit( int* pargc, char** argv )
      * Grab the environment variable indicating the X display to use.
      * This is harmless under Win32, so let's let it stay here...
      */
+#if TARGET_HOST_WIN32
+    if ( !getenv( "DISPLAY" ) )
+      displayName = strdup( "" );
+    else
+#endif
     displayName = strdup( getenv( "DISPLAY" ) );
 
     /*