`diagnostic_information_what` returns 0 when no `error_info` is added to exception

[Pavel Machyniak <machyniak@…>]

Scenario:

• throwing derived exception from both boost::exception and std::exception
• catching as std::exception
• logging with e.what(), what is overridden and uses boost::diagnostic_information_what
• when throwing such exception with error_info added, everything is fine
• when throwing such exception without error_info added, no string is returned from diagnostic_information_what, at least I would expect the string like "Dynamic exception type: struct TestException"

Observations: In diagnostic_information_what implementation is correct string generated by exception_detail::diagnostic_information_impl but is trashed and exception_detail::get_diagnostic_information returns 0 in described case.

Workaround: We are using internal boost::exception_detail::diagnostic_information_impl instead of boost::diagnostic_information_what.

[Emil Dotchevski]

fixed, trunk revision 70988