Parse error when arrays are empty

[mboelstra]

Hi,

The parser fails when the following JSON is provided: {"myArray": [] }

In code:
static char str[] = "{ "myArray": [] }";
json_value * root = json_parse(str, strlen(str));

This is because malloc is called with a size of 0, due to the empty array. However some implementations of malloc will return NULL when asked to allocate 0 bytes and in this case the parser stops. I think this is wrong. In my opinion the parser should not try to allocate 0 bytes. A simple check in the newValue method for the json_array case can prevent this:

In code:
if (value->u.array.length == 0) {
break;
}

With these three lines of code the parser can also handle the above input.

Regards,
Matthijs

[jamesamcl]

Thanks, I didn't know malloc could do that. In 63be13a I made it so that json_alloc allocates 1 byte if you request zero, just because I like the peace of mind that alloc always returns a valid pointer if it succeeds.

[jamesamcl]

And then changed my mind and did it your way in 8c4b18f because I realised my way violated the "[never] allocates more memory than it needs" claim.

Do you have a name for the AUTHORS file?

[mboelstra]

This website (http://www.cplusplus.com/reference/cstdlib/malloc/) says the return value of malloc is implementation defined when allocating 0 bytes.
You have to be sure the memory is freed. So just allocating 1 byte can be dangerous.

On 30 jun. 2014, at 18:27, James McLaughlin notifications@github.com wrote:

Thanks, I didn't know malloc could do that. In 63be13a I made it so that json_alloc allocates 1 byte if you request zero, just because I like the peace of mind that alloc always returns a valid pointer if it succeeds.

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[mboelstra]

My full name is: Matthijs Boelstra

Thanx!

On 30 jun. 2014, at 18:31, James McLaughlin notifications@github.com wrote:

And then changed my mind and did it your way in 8c4b18f because I realised my way violated the "[never] allocates more memory than it needs" claim.

Do you have a name for the AUTHORS file?

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[jamesamcl]

Thank you. 👍