json parser crash if having a large number integer in message

[alexhhj]

• What is the issue you have?

• Please describe the steps to reproduce the issue. Can you provide a small but working code example?
  I have a test case running on this json library .
  The message is as below
  {
  "testList": [
  {
  "id": "160013002243",
  "customerNumber": 111000000000000000009999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999977777777777777777777777777777777777774444444444444444444444444444444444444444444444444499999999999999999999999999444444444444444444444444444444444444444444444444444444444444444444444444444444444444444444444444,
  "name": "Alex Test for Json",
  },
  ]
  }
  Then the json parser crashes even with try-catch in C++.

It could work well if the "customer Number" is string type with "".

I am running on a Linux system on am335x.

Linux version 4.4.19 (jenkins@imvisionfw) (gcc version 5.2.0 (crosstool-NG crosstool-ng-1.22.0) ) #1 PREEMPT Thu May 16 04:11:13 CDT 2019

JSON for Modern C++ version is 3.5.0

[gregmarr]

It's probably throwing an out of range exception from the parser. How are you catching exceptions?

[alexhhj]

                        try 
			{  
				//valid_json = true;
				json::parse(request_post);
			}
			catch (json::parse_error& e)
			{
				//valid_json = false;
			printf("load JSON error %s %d message %s  n", __FUNCTION__, __LINE__, e.what());
				
			}

Just try and catch . But no error report just crash

[nickaein]

For out of range numbers, exception nlohmann::json::out_of_range will be thrown.

When in doubt, catch the base class nlohmann::json::exception to make sure you no exception can escape:

try 
{  
    json::parse(request_post);
}
catch (json::parse_error& e)
{
    std::cout << "Parse error:" << e.what() << std::endl;
}
catch (json::out_of_range& e)
{
    std::cout << "Out of range:" << e.what() << std::endl;
}
catch (json::exception& e)
{
    std::cout << "JSON exception: " << e.what() << std::endl;
}
// not really needed 
catch (std::exception& e)
{
    std::cout << "Unknown exception" << e.what() << std::endl;   
}

Note: The std::exception block is not needed since all library exceptions are derived from json::exception. If in some case the library throws std::exception, I believe it is considered as a bug.

[alexhhj]

Thanks