Due to uninitialized values of charsetid in _oci_open_session() and charset in oci_do_connect() a segfault occures when charset paramter is ommited in OCILogon().

Following patch can fix it:

--- php-4.3.2RC1.orig/ext/oci8/oci8.c	2003-01-31 15:21:19.000000000 +0100
+++ php-4.3.2RC1/ext/oci8/oci8.c	2003-04-14 10:53:33.000000000 +0200
@@ -2154,7 +2154,7 @@
 	OCISvcCtx *svchp = 0;
 	char *hashed_details;
 #ifdef HAVE_OCI9
-	ub2 charsetid;
+	ub2 charsetid = 0;
 #endif
 	TSRMLS_FETCH();
 
@@ -2218,10 +2218,11 @@
 							OCI(pEnv),
 							charset));
 		
-		session->charsetId = charsetid;
 		oci_debug("oci_do_connect: using charset id=%d",charsetid);
 	}
 	
+	session->charsetId = charsetid;
+
 	/* create an environment using the character set id, Oracle 9i+ ONLY */
 	CALL_OCI(OCIEnvNlsCreate(
 				&session->pEnv,
@@ -2648,6 +2649,7 @@
 		username = Z_STRVAL_PP(userParam);
 		password = Z_STRVAL_PP(passParam);
 		dbname = Z_STRVAL_PP(dbParam);
+		charset = "";
 	} else if (zend_get_parameters_ex(2, &userParam, &passParam) == SUCCESS) {
 		convert_to_string_ex(userParam);
 		convert_to_string_ex(passParam);
@@ -2655,6 +2657,7 @@
 		username = Z_STRVAL_PP(userParam);
 		password = Z_STRVAL_PP(passParam);
 		dbname = "";
+		charset = "";
 	} else {
 		WRONG_PARAM_COUNT;
 	}