The problem was mostly that, in the past, we did not worry if
question_attempt_step.id changed during regrade (because we deleted the
old step row and inserted a new one). However, now that steps can have
associated files, we can't be that slack, becuase the step id is used as
the file itemid.
So, now, we have to update the existing rows during a regrade. We do
this by having the question engine tell the question_engine_unit_of_work
that the step has first been deleted, and then added back. Then we make
the unit-of-work spot that delete + add = update.
This also means that during regrading, we have to pass around some extra
ids so that new steps know the id of the step they are replacing.
Naturally, this requires some quite trickly logic, so I finally got
around to writing unit tests for question_engine_unit_of_work, which is
a good thing.
Along the way I also got around to renaming
question_attempt->set_number_in_usage, which got missed out when
everthing else was renamed to slot ages ago.
Finally, while working on this code, I noticed and fixed some PHPdoc
comments.
This was one of those innocent seeming issues where, once you start
digging, you find a mess. In this case, the code that is now in
question_wizard_form::add_hidden_fields used to exist in four different
places, in four inconsistent versions. This is now all nicely
re-factored, and that solves the problem.
Along the way, I found and fixed some wrong string references in
qtype_random, and stripped out some unnecessary &s in function
declarations.
Without this, restoring backups made with the OU's custom 'restore from
1.9' feature, and possibly other people's custom converstion code, does
not work properly.
Also, fix poor recordset code.
Even if the site identifier is not defined in the source 1.9 backup then the
converted 2.0 version should still contain the element to prevent PHP
notices on direct assignment.
On 20120102 version was incorrectly bumped to 2012-02-02. So,
until then (< 1mo) we are going to be incrementing decimal digits
only and not date ones (first 8).
