Description:
------------
If SQLSetStmtAttr fails in odbc_handle_preparer (file odbc_driver.c), pdo_odbc_stmt_error is called. At this time, stmt->driver_data is still NULL.

pdo_odbc_error then tries to store the error data to einfo of the not present stmt->driver_data => SIGSEGV.

Second issue is, that caller of odbc_handle_preparer expects the error in the error structure of the db connection handle.

Possible fix:
--- ext/pdo_odbc/odbc_driver.c.orig     2014-06-17 18:18:14.529836822 +0200
+++ ext/pdo_odbc/odbc_driver.c  2014-06-17 18:41:55.907685218 +0200
@@ -67,7 +67,7 @@
        pdo_odbc_stmt *S = NULL;
        pdo_error_type *pdo_err = &dbh->error_code;

-       if (stmt) {
+       if (stmt && stmt->driver_data) {
                S = (pdo_odbc_stmt*)stmt->driver_data;

                einfo = &S->einfo;
@@ -185,7 +185,7 @@
        if (cursor_type != PDO_CURSOR_FWDONLY) {
                rc = SQLSetStmtAttr(S->stmt, SQL_ATTR_CURSOR_SCROLLABLE, (void*)SQL_SCROLLABLE, 0);
                if (rc != SQL_SUCCESS && rc != SQL_SUCCESS_WITH_INFO) {
-                       pdo_odbc_stmt_error("SQLSetStmtAttr: SQL_ATTR_CURSOR_SCROLLABLE");
+                       pdo_odbc_error(stmt->dbh, stmt, S->stmt, "SQLSetStmtAttr: SQL_ATTR_CURSOR_SCROLLABLE", __FILE__, __LINE__ TSRMLS_CC);
                        SQLFreeHandle(SQL_HANDLE_STMT, S->stmt);
                        if (nsql) {
                                efree(nsql);