Roundtrip fail

[miloyip]

Recently I encountered crash on some platform (Ubuntu/gcc-5) during a roundtrip of this JSON:

[-9223372036854775808]

I saved it in valid-0013.json and run the test, which reproduced the problem but did not crash on my machine (OS X El Capitan/clang):

...
Running test: valid-0013.json
measured len: 7
serialized len: 7
serialized:
[ -e ]
Failed to re-parse: 1:0: Expected digit after `e`

I found that several tests in test/main.cc are also failed. I make a note here as well.

...
Running test: valid-0003.json
measured len: 36
serialized len: 36
serialized:
{ "min": -1e+28.0, "max": 1e+28.0 }
Failed to re-parse: 1:0: Unexpected `.` in object
...
Running test: valid-0005.json
measured len: 106
serialized len: 106
serialized:
[ 12.0004, 1.7734, 15, -42, -1.7734, 1e+28.0, -1e+28.0, 1e-28.0, -1e-28.0, -18.3872, -2.1, -1.23457e+06 ]
Failed to re-parse: 1:0: Expected , before .
...
Running test: valid-0008.json
measured len: 59
serialized len: 59
serialized:
[ 400000.0, 4e-07.0, 400000.0, 4e+06.0, 4e-06.0, 4e+06.0 ]
Failed to re-parse: 1:0: Expected , before .
...

BTW, I discovered this during integrating Travis in https://github.com/miloyip/nativejson-benchmark .

[be5invis]

I've found some crashes either, especially when dealing with json_double values very close to an integer, which causes json_serialize_ex out-of-range.