Dangling pointer

[jacobwilliams]

From another ticket:

 Test removing data from the json structure:
Runtime Error: /home/themos/json-fortran/src/json_value_module.F90, line
1991: Dangling pointer P%PREVIOUS used as argument to intrinsic function
ASSOCIATED
Target was DEALLOCATEd at line 1995 of
/home/themos/json-fortran/src/json_value_module.F90
Program terminated by fatal error
/home/themos/json-fortran/src/json_value_module.F90, line 1991: Error
occurred in JSON_VALUE_MODULE:JSON_VALUE_DESTROY
/home/themos/json-fortran/src/json_value_module.F90, line 1978: Called by
JSON_VALUE_MODULE:JSON_VALUE_DESTROY
/home/themos/json-fortran/src/json_value_module.F90, line 2099: Called by
JSON_VALUE_MODULE:JSON_VALUE_REMOVE
/home/themos/json-fortran/src/tests/jf_test_1.f90, line 293: Called by
JF_TEST_1_MOD:TEST_1
/home/themos/json-fortran/src/tests/jf_test_1.f90, line 500: Called by
JF_TEST_1
Aborted (core dumped)

May be related to something mentioned here: https://software.intel.com/en-us/forums/intel-fortran-compiler-for-linux-and-mac-os-x/topic/270495

Note: I don't have access to the NAG compiler, but it does work with both the Intel and Gfortran compilers.

[jacobwilliams]

@ThemosTsikas Could you try the 307-nag-fix branch and tell me if that fixes this issue on the NAG compiler?

Or anyone else who has access to the NAG compiler?

[jacobwilliams]

Note: this was a dangling pointer bug (as indicated in the link above) caused in the destroy routine. I think the same or similar crash is happening in the latest Intel compiler. The change in #350 fixes it.