Missing null writes when writing Object[] values

[georgewfraser]

When writing arrays to CSV, if there is a null, columns get written out of order. Reproduced in 2.7.1 with this test: https://gist.github.com/georgewfraser/164647fbaca61aadf9ee

Possibly related to #68

[cowtowncoder]

Thank you for reporting this, providing test case. Hope to look into this soon.

[cowtowncoder]

I can reproduce this locally; looks like "all nulls" somehow does not work as expected.

[cowtowncoder]

More likely related to #106: looks like nulls for "array in array" are suppressed. This could be somewhat problematic even for other entries since "null value" would not get written.

[cowtowncoder]

This may be tricky to fix. The problem is that suppression serves a function (2 tests fail if it's removed), but I hope there's a way to refine heuristics further to support all usage -- perhaps by further separating output of the first column or something like that (and not just by "array in array" structure).

[cowtowncoder]

moved: FasterXML/jackson-dataformats-text#10