QSQL/ODBC: fix regression (trailing NUL)

Origin: upstream, https://code.qt.io/cgit/qt/qtbase.git/commit/?id=9020034b3b6a3a81
Last-Update: 2023-06-30

When we fixed the callers of toSQLTCHAR() to use the result's size()
instead of the input's (which differ, if sizeof(SQLTCHAR) != 2), we
exposed callers to the append(0), which changes the size() of the
result QVLA. Callers that don't rely on NUL-termination (all?) now saw
an additional training NUL.

Fix by not NUL-terminating, and changing the only user of SQL_NTS to
use an explicit length.

Gbp-Pq: Name sql_odbc_fix_unicode_check.diff

diff --git a/src/plugins/sqldrivers/odbc/qsql_odbc.cpp b/src/plugins/sqldrivers/odbc/qsql_odbc.cpp
index 5e1eefebdab3b1d5c9dd12bc1ec88a8dc1399e4a..c713893ab27b9eaf9aba114bcc08d55dbe456592 100644 (file)
--- a/src/plugins/sqldrivers/odbc/qsql_odbc.cpp
+++ b/src/plugins/sqldrivers/odbc/qsql_odbc.cpp
@@ -125,7 +125,6 @@ inline static QVarLengthArray<SQLTCHAR> toSQLTCHAR(const QString &input)
 {
     QVarLengthArray<SQLTCHAR> result;
     toSQLTCHARImpl(result, input);
-    result.append(0); // make sure it's null terminated, doesn't matter if it already is, it does if it isn't.
     return result;
 }
 
@@ -2119,7 +2118,8 @@ void QODBCDriverPrivate::checkUnicode()
         QLatin1String("select 'test' from dual"),
     };
     for (const auto &statement : statements) {
-        r = SQLExecDirect(hStmt, toSQLTCHAR(statement).data(), SQL_NTS);
+        auto encoded = toSQLTCHAR(statement);
+        r = SQLExecDirect(hStmt, encoded.data(), SQLINTEGER(encoded.size()));
         if (r == SQL_SUCCESS)
             break;
     }