Bug#38486: Crash when using cursor protocol

Post-merge fix: mysql_client_test.c is compiled by C compilers
and some C compilers don't support mixed declarations and code
and it's explicitly forbidden by ISO C90.

tests/mysql_client_test.c:
  Don't mix declarations and code.

tests/mysql_client_test.c

@@ -16196,25 +16196,28 @@ static void test_bug32265()
 
 static void test_bug38486(void)
 {
+  MYSQL_STMT *stmt;
+  const char *stmt_text;
+  unsigned long type= CURSOR_TYPE_READ_ONLY;
+
+  DBUG_ENTER("test_bug38486");
   myheader("test_bug38486");
 
-    MYSQL_STMT *stmt;
   stmt= mysql_stmt_init(mysql);
-    unsigned long type= CURSOR_TYPE_READ_ONLY;
   mysql_stmt_attr_set(stmt, STMT_ATTR_CURSOR_TYPE, (void*)&type);
-    const char *sql= "CREATE TABLE t1 (a INT)";
-    mysql_stmt_prepare(stmt,sql,strlen(sql));
-    
+  stmt_text= "CREATE TABLE t1 (a INT)";
+  mysql_stmt_prepare(stmt, stmt_text, strlen(stmt_text));
   mysql_stmt_execute(stmt);
   mysql_stmt_close(stmt);
 
   stmt= mysql_stmt_init(mysql);
   mysql_stmt_attr_set(stmt, STMT_ATTR_CURSOR_TYPE, (void*)&type);
-    const char *sql2= "INSERT INTO t1 VALUES (1)";
-    mysql_stmt_prepare(stmt,sql2,strlen(sql2));
+  stmt_text= "INSERT INTO t1 VALUES (1)";
+  mysql_stmt_prepare(stmt, stmt_text, strlen(stmt_text));
   mysql_stmt_execute(stmt);
-    
   mysql_stmt_close(stmt);
+
+  DBUG_VOID_RETURN;
 }