Fix OTools::ThrowException

First, it used 5-character buffer for SQL state, where MS documentation
for SQLGetDiagRec specifies, that the buffer is for five-character code
plus terminating NULL. The declaration of the function in Windows Kit's
sqlucode.h uses decoration '_Out_writes_opt_(6)' for the parameter.

Next, SQLGetDiagRec may fail or return SQL_NO_DATA;  and then, the data
in buffers will be undefiled.

Change-Id: Ia36555b4fe4f49c8803a25f8fc1cc1a3b6ac4ddc
Reviewed-on: https://gerrit.libreoffice.org/c/core/+/171238
Tested-by: Jenkins
Reviewed-by: Mike Kaganski <mike.kaganski@collabora.com>

1 files changed, 13 insertions, 7 deletions

diff --git a/connectivity/source/drivers/odbc/OTools.cxx b/connectivity/source/drivers/odbc/OTools.cxx
index 999324a4d571..0909b03f14b2 100644
--- a/connectivity/source/drivers/odbc/OTools.cxx
+++ b/connectivity/source/drivers/odbc/OTools.cxx
@@ -203,7 +203,7 @@ void OTools::ThrowException(const OConnection* _pConnection,
     // corresponding for hdbc.
     if (bUseWChar && _pConnection->functions().has(ODBC3SQLFunctionId::GetDiagRecW))
     {
-        SQLWCHAR szSqlState[5];
+        SQLWCHAR szSqlState[6];
         SQLWCHAR szErrorMessage[SQL_MAX_MESSAGE_LENGTH];
         szErrorMessage[0] = '\0';
         SQLSMALLINT cchErrorMsg = 0;
@@ -212,12 +212,15 @@ void OTools::ThrowException(const OConnection* _pConnection,
                          szSqlState,
                          &pfNativeError,
                          szErrorMessage, std::size(szErrorMessage) - 1, &cchErrorMsg);
-        errorMessage = toUString(szErrorMessage, cchErrorMsg);
-        sqlState = toUString(szSqlState, std::size(szSqlState));
+        if (SQL_SUCCEEDED(n))
+        {
+            errorMessage = toUString(szErrorMessage, cchErrorMsg);
+            sqlState = toUString(szSqlState, 5);
+        }
     }
     else
     {
-        SQLCHAR szSqlState[5];
+        SQLCHAR szSqlState[6];
         SQLCHAR szErrorMessage[SQL_MAX_MESSAGE_LENGTH];
         szErrorMessage[0] = '\0';
         SQLSMALLINT pcbErrorMsg = 0;
@@ -226,9 +229,12 @@ void OTools::ThrowException(const OConnection* _pConnection,
                          szSqlState,
                          &pfNativeError,
                          szErrorMessage,sizeof szErrorMessage - 1,&pcbErrorMsg);
-        rtl_TextEncoding _nTextEncoding = osl_getThreadTextEncoding();
-        errorMessage = toUString(szErrorMessage, pcbErrorMsg, _nTextEncoding);
-        sqlState = toUString(szSqlState, std::size(szSqlState), _nTextEncoding);
+        if (SQL_SUCCEEDED(n))
+        {
+            rtl_TextEncoding _nTextEncoding = osl_getThreadTextEncoding();
+            errorMessage = toUString(szErrorMessage, pcbErrorMsg, _nTextEncoding);
+            sqlState = toUString(szSqlState, 5, _nTextEncoding);
+        }
     }
     OSL_ENSURE(n != SQL_INVALID_HANDLE,"SdbODBC3_SetStatus: SQLError returned SQL_INVALID_HANDLE");
     OSL_ENSURE(n == SQL_SUCCESS || n == SQL_SUCCESS_WITH_INFO || n == SQL_NO_DATA_FOUND || n == SQL_ERROR,"SdbODBC3_SetStatus: SQLError failed");