Fixed a term encoding problem

See http://www.erlang.org/doc/man/ei.html#ei_decode_string

c_src/sqlite3_drv.c

@@ -403,11 +403,24 @@ static int bind_parameters(
   int i, cur_list_size = -1, param_index = 1, param_indices_are_explicit = 0, result = 0;
   long param_index_long;
   char param_name[MAXATOMLEN + 1]; // parameter names shouldn't be longer than 256!
+  char *acc_string;
   result = ei_decode_list_header(buffer, p_index, &cur_list_size);
   if (result) {
+    // probably all parameters are integers between 0 and 255
+    // and the list was encoded as string (see ei documentation)
+    ei_get_type(buffer, p_index, p_type, p_size);
+    if (*p_type != ERL_STRING_EXT) {
       return output_error(drv, SQLITE_ERROR,
                           "error while binding parameters");
     }
+    acc_string = driver_alloc(sizeof(char*) * (*p_size + 1));
+    ei_decode_string(buffer, p_index, acc_string);
+    for (param_index = 1; param_index <= *p_size; param_index++) {
+      sqlite3_bind_int(statement, param_index, (int) acc_string[param_index - 1]);
+    }
+    driver_free(acc_string);
+    return 0;
+  }
   for (i = 0; i < cur_list_size; i++) {
     if (*p_index >= buffer_size) {
       return output_error(drv, SQLITE_ERROR,

test/sqlite3_test.erl

@@ -47,7 +47,8 @@ all_test_() ->
       ?FuncTest(select_many_records),
       ?FuncTest(nonexistent_table_info),
       ?FuncTest(large_number),
-      ?FuncTest(unicode)]}.
+      ?FuncTest(unicode),
+      ?FuncTest(acc_string_encoding)]}.
 
 open_db() ->
     sqlite3:open(ct, [in_memory]).
@@ -216,6 +217,9 @@ unicode() ->
     sqlite3:write(ct, unicode, [{str, UnicodeString}]),
     ?assertEqual([{unicode:characters_to_binary(UnicodeString)}], rows(sqlite3:read_all(ct, unicode))). 
 
+acc_string_encoding() ->
+    ?assertEqual([{62}], rows(sqlite3:sql_exec(ct, "SELECT ? + ?", [30,32]))).
+
 prepared_test() ->
     Columns = ["id", "name", "age", "wage"],
     Abby = {1, <<"abby">>, 20, 2000},