Index: drivers/pstex.c
--- drivers/pstex.c.orig
+++ drivers/pstex.c
@@ -243,7 +243,8 @@ proc_str( PLStream *pls, EscText *args )
         fprintf( fp, "\\special{ps: 0 0 0 setrgbcolor}{" );
 
     fprintf( fp, "%% Your text follows:\n" );
-    fprintf( fp, "%s\n", cptr );
+    if (strlen(cptr) > 0)
+      fprintf( fp, "%s\n", cptr );
     fprintf( fp, "}}}}" );
 
     //
@@ -274,6 +275,11 @@ parse_str( const char *str, char *dest )
                           "psi",     "Psi",     "omega",  "Omega" };
 
     plgesc( &esc );
+
+    if (str == NULL) {
+      *tp = '\0';
+      return;
+    }
 
     while ( *str )
     {