Description:
------------
Hi

We have a problem with the (ODBC) persistent database connection. We have found that every PHP-session, using the same dsn, user and password, are getting the same persistent connection by a reasonable chance.
Also meaning that if a database transaction was not finished, other PHP-session can do a rollback or commit of that transaction. 

Due to resource problems with (temporarily) connections the persistent connections are used, so we do. But ?leftovers? of database transactions were not intended. 
Also if one want to open an another connection in one PHP-session the result is the same connection. (E.g. we use a DB-log-file to log errors en warning, so you don?t want to do a rollback on the DB-log-file, in peculiar.)


To overcome these problems one has to tag the connections. I suggest to use a new parameter on ODBC_(p)connect: Tag, a string parameter. If used it tries to re-connect to the connection with the same tag, if not existing it creates a new-connection. 
For example the tag parameter is filled with the session_ID() to ensure that a connection is bounded to one PHP-session. But also an extension on this value is possible:  (Session_ID() + ?Log?) or (Session_ID() + ?Data?).
And if somebody does not uses this tag parameter, it works in the old way, so these solution is downwards compatible.


Reproduce code:
---------------
So the adjusted description will be:
resource odbc_pconnect (string $dsn , string $user , string $password [, int $cursor_type [, string $tag ]  ] )

Eg ODBC_pconnect( $dns, $user,, $password, SQL_CUR_DEFAULT, Session_ID()+ ?LOG?)

The change of the PHP source of the function odbc_do_connect is minimal:
void odbc_do_connect(INTERNAL_FUNCTION_PARAMETERS, int persistent)
{
	char    *db = NULL;
	char    *uid = NULL;
	char    *pwd = NULL;
	char    *tag = NULL;
	zval **pv_db, **pv_uid, **pv_pwd, **pv_opt, **pv_tag;
	odbc_connection *db_conn;
	char *hashed_details;
	int hashed_len, cur_opt;

	/*  Now an optional 4th parameter specifying the cursor type
	 *  defaulting to the cursors default
	 */
	switch(ZEND_NUM_ARGS()) {
		case 3:	
			if (zend_get_parameters_ex(3, &pv_db, &pv_uid, &pv_pwd) == FAILURE) {
				WRONG_PARAM_COUNT;
			}
			/* Use Default: Probably a better way to do this */
			cur_opt = SQL_CUR_DEFAULT;
			tag = '';
			break;
		case 4:
			if (zend_get_parameters_ex(4, &pv_db, &pv_uid, &pv_pwd, &pv_opt) == FAILURE) {
				WRONG_PARAM_COUNT;
			}
			convert_to_long_ex(pv_opt);
			cur_opt = Z_LVAL_PP(pv_opt);

			/* Confirm the cur_opt range */
			if (! (cur_opt == SQL_CUR_USE_IF_NEEDED || 
				cur_opt == SQL_CUR_USE_ODBC || 
				cur_opt == SQL_CUR_USE_DRIVER || 
				cur_opt == SQL_CUR_DEFAULT) ) {
				php_error_docref(NULL TSRMLS_CC, E_WARNING, "Invalid Cursor type (%d)", cur_opt);
				RETURN_FALSE;
			}
			tag = '';
			break;
		case 5:
			if (zend_get_parameters_ex(5, &pv_db, &pv_uid, &pv_pwd, &pv_opt, &pv_tag) == FAILURE) {
				WRONG_PARAM_COUNT;
			}
			convert_to_long_ex(pv_opt);
			cur_opt = Z_LVAL_PP(pv_opt);

			/* Confirm the cur_opt range */
			if (! (cur_opt == SQL_CUR_USE_IF_NEEDED || 
				cur_opt == SQL_CUR_USE_ODBC || 
				cur_opt == SQL_CUR_USE_DRIVER || 
				cur_opt == SQL_CUR_DEFAULT) ) {
				php_error_docref(NULL TSRMLS_CC, E_WARNING, "Invalid Cursor type (%d)", cur_opt);
				RETURN_FALSE;
			}
      			convert_to_string_ex(pv_tag);
			tag = Z_STRVAL_PP(pv_tag);
			break;
		default:
			WRONG_PARAM_COUNT;
			break;
	}

	convert_to_string_ex(pv_db);
	convert_to_string_ex(pv_uid);
	convert_to_string_ex(pv_pwd);

	db = Z_STRVAL_PP(pv_db);
	uid = Z_STRVAL_PP(pv_uid);
	pwd = Z_STRVAL_PP(pv_pwd);

	if (ODBCG(allow_persistent) <= 0) {
		persistent = 0;
	}

	hashed_len = spprintf(&hashed_details, 0, "%s_%s_%s_%s_%d_%s", ODBC_TYPE, db, uid, pwd, cur_opt, tag);


Expected result:
----------------
.

Actual result:
--------------
.