patch #1668: clarify envvar docs; rename THREADDEBUG to PYTHONTHREADDEBUG.
diff --git a/Python/import.c b/Python/import.c
index 8094f7d..d9550f5 100644
--- a/Python/import.c
+++ b/Python/import.c
@@ -1630,7 +1630,7 @@
 	FILEFINDBUF3 ffbuf;
 	APIRET rc;
 
-	if (getenv("PYTHONCASEOK") != NULL)
+	if (Py_GETENV("PYTHONCASEOK") != NULL)
 		return 1;
 
 	rc = DosFindFirst(buf,