The QMYSQLResult::fetchNext() function currently ignores errors and data
truncation that occurs in prepared statements.

The attached patch simply adds a code block that checks for errors and data
truncation and sets lastError appropriately, as does the existing code block in
QMYSQLResult::fetch().

--


Index: qt-x11-opensource-src-4.5.3/src/sql/drivers/mysql/qsql_mysql.cpp
===================================================================
--- qt-x11-opensource-src-4.5.3.orig/src/sql/drivers/mysql/qsql_mysql.cpp	2009-11-07 04:45:00.000000000 -0500
+++ qt-x11-opensource-src-4.5.3/src/sql/drivers/mysql/qsql_mysql.cpp	2009-11-12 19:05:41.000000000 -0500
@@ -506,8 +506,18 @@
         return false;
     if (d->driver->d->preparedQuerys) {
 #if MYSQL_VERSION_ID >= 40108
-        if (mysql_stmt_fetch(d->stmt))
+        int nRC = mysql_stmt_fetch(d->stmt);
+        if (nRC)
+        {
+#ifdef MYSQL_DATA_TRUNCATED
+            if (nRC == 1 || nRC == MYSQL_DATA_TRUNCATED)
+#else
+            if (nRC == 1)
+#endif // MYSQL_DATA_TRUNCATED
+                setLastError(qMakeStmtError(QCoreApplication::translate("QMYSQLResult",
+                         "Unable to fetch data"), QSqlError::StatementError, d->stmt));
             return false;
+        }
 #else
         return false;
 #endif