ICU4C executor uses JSON-C, which has problems parsing null character \u0000 and surrogate pairs

[sven-oly]

This may be the source of problems parsing the the SHORT and NON_IGNORABLE data. Each of these has > 600 test failures. E.g., C-string input stops on a null byte.

Suggest that we use a better JSON parser that handle null bytes and UTF-16.

[sven-oly]

Marked as known issue in PR #493

[sffc]

We fixed the nul byte issue, but there is another issue involving certain ranges of supplemental code points, fixed upstream in json-c/json-c#893.

[sven-oly]

Should we download the code for JSON-C and package it with our application?

[sffc]

nah, if we wait some time, json-c will be released and the fix will become available. Why make more work for ourselves; it is what we have the Known Issue mechanism for.

[sffc]

I'll keep this open until the fixed json-c is released and widely available in package managers.