Dsn could be leaked if connection re-used after disconnect.

Disabled one check in the test in unicode to reduce noise with valgrind

Author: lawrinn

driver/ma_connection.cpp

@@ -141,8 +141,8 @@ bool MADB_Dbc::CheckConnection()
 SQLRETURN MADB_SQLDisconnect(SQLHDBC ConnectionHandle)
 {
   SQLRETURN ret= SQL_ERROR;
-  MADB_Dbc* Connection= (MADB_Dbc*)ConnectionHandle;
-  MADB_List* Element, * NextElement;
+  MADB_Dbc *Connection= (MADB_Dbc*)ConnectionHandle;
+  MADB_List *Element, *NextElement;
 
   MDBUG_C_ENTER(Connection, "SQLDisconnect");
   MDBUG_C_DUMP(Connection, ConnectionHandle, 0x);
@@ -161,7 +161,9 @@ SQLRETURN MADB_SQLDisconnect(SQLHDBC ConnectionHandle)
     NextElement= Element->next;
     MADB_DescFree((MADB_Desc*)Element->data, FALSE);
   }
-
+  // Even if the handle is re-used - we won't need this Dsn
+  MADB_DSN_Free(Connection->Dsn);
+  Connection->Dsn= nullptr;
   Connection->mariadb= nullptr;
   if (Connection->guard && !Connection->guard->isClosed())
   {

driver/ma_dsn.c

@@ -407,7 +407,7 @@ my_bool MADB_ReadDSN(MADB_Dsn *Dsn, const char *KeyValue, my_bool OverWrite)
     {
       unsigned int KeyIdx= DsnKeys[i].IsAlias ? DsnKeys[i].DsnOffset : i;
 
-      if (SQLGetPrivateProfileString(Dsn->DSNName, DsnKeys[i].DsnKey, "", KeyVal, 1024, "ODBC.INI") > 0)
+      if (SQLGetPrivateProfileString(Dsn->DSNName, DsnKeys[i].DsnKey, "", KeyVal, sizeof(KeyVal), "ODBC.INI") > 0)
       {
         if (!MADB_DsnStoreValue(Dsn, KeyIdx, KeyVal, OverWrite))
           return FALSE;

test/bulk.c

@@ -728,6 +728,8 @@ ODBC_TEST(t_odbc235)
     (SQLPOINTER)1, 0));
 
   OK_SIMPLE_STMT(Stmt, "DROP TABLE IF EXISTS t_odbc235");
+  CHECK_STMT_RC(wStmt, SQLFreeStmt(wStmt, SQL_DROP));
+
   return OK;
 }
 

test/tap.h

@@ -1228,7 +1228,11 @@ int run_tests_ex(MA_ODBC_TESTS *tests, BOOL ProvideWConnection)
     /* reset Statement */
     fflush(stdout);
   }
-
+  if (wConnection)
+  {
+    SQLDisconnect(wConnection);
+    SQLFreeHandle(SQL_HANDLE_DBC, wConnection);
+  }
   ODBC_Disconnect(Env,Connection,Stmt);
 
   if (failed)

test/unicode.c

@@ -258,11 +258,14 @@ ODBC_TEST(sqlchar)
   FAIL_IF(SQLFetch(hstmt1) != SQL_NO_DATA_FOUND, "eof expected");
 
   CHECK_STMT_RC(hstmt1, SQLFreeStmt(hstmt1, SQL_DROP));
+// This check creates lots of noise with valgrind from inside unixODBC
+#ifndef MEMCHECK_SKIP_TEST
   // We probably could do that in driver as well, TODO: but do we really need
   if (using_dm())
   {
     is_num(SQLFreeHandle(SQL_HANDLE_STMT, hstmt1), SQL_INVALID_HANDLE);
   }
+#endif
   CHECK_DBC_RC(hdbc1, SQLDisconnect(hdbc1));
   CHECK_DBC_RC(hdbc1, SQLFreeConnect(hdbc1));