there is some problem with the function "encode_string_as_pointer"!!!!!

[AIChangjiang]

it shoud change "~" to "0"，but this function has change "" to "~1", there also have problem with the "/";
the right implement may be as follow.

static void encode_string_as_pointer(unsigned char *destination, const unsigned char *source)
{
for (; source[0] != '\0'; (void)source++, destination++)
{
if (source[0] == '/')
{
destination[1] = '';
destination[1] = '1';
destination++;
}
else if (source[0] == '')
{
destination[0] = '~';
destination[1] = '0';
destination++;
}
else
{
destination[0] = source[0];
}
}

destination[0] = '\0';

}

[Alanscut]

Hi, @AIChangjiang , can you provide more information about it, what would happen if not change the original implementation and what bug you occurred when use this function.

[AIChangjiang]

Hello. Thank you for your reply.
I had a problem when getting the JSON PONTER，For example, there is a json body like this
{"m~n", "test"}
I will get the json poniter "/m~1n"，according to the rfc6901，i should get the result is "/m~0n",
so i think the function encode_string_as_pointer is something wrong.

[Alanscut]

Hi @AIChangjiang , yes, you are right. encode_string_as_pointer seems has some problem according to the rfc6901.

Here is a snippet I extracted from the rfc6901 document:

   A JSON Pointer is a Unicode string (see [RFC4627], Section 3)
   containing a sequence of zero or more reference tokens, each prefixed
   by a '/' (%x2F) character.

   Because the characters '~' (%x7E) and '/' (%x2F) have special
   meanings in JSON Pointer, '~' needs to be encoded as '~0' and '/'
   needs to be encoded as '~1' when these characters appear in a
   reference token.

According to this, I think the right implement may be as follow:

static void encode_string_as_pointer(unsigned char *destination, const unsigned char *source)
{
    for (; source[0] != '\0'; (void)source++, destination++)
    {
        if (source[0] == '/')
        {
            destination[0] = '~';
            destination[1] = '1';
            destination++;
        }
        else if (source[0] == '~')
        {
            destination[0] = '~';
            destination[1] = '0';
            destination++;
        }
        else
        {
            destination[0] = source[0];
        }
    }

    destination[0] = '\0';
}

What's you opinion?

[AIChangjiang]

yes, I think your modifications are correct. That's what I thought.
Thanks for your attention.