[entity] ensure the .related(entities=False) parameter is honored all the way down (closes #2755994)
As of today, such a call will always fill the relation cache by
calling .entities() on every single related rset entry.
As a consequence, the `limit` parameter handling also had to be fixed.
It was bogus in the following ways:
* not used in the related_rql, hence potentially huge database
requests, but also actually
* foolishly used in the .entities()-calling cache routine we now
bypass (this changeset ticket's main topic)
Now:
* we set a limit on the rql expression, and
* forbid caching if given a non-None limit (as we don't want to make
the cache handling code more complicated than it is already)
With this, entity.unrelated gets a better limit implementation (so the
code in related/unrelated is nice and symmetric)
Risk:
* _cw_relation_cache disappears completely, which is good, but this is
Python, so you never know ...
function datetuple(d) {
return [d.getFullYear(), d.getMonth()+1, d.getDate(),
d.getHours(), d.getMinutes()];
}
function pprint(obj) {
print('{');
for(k in obj) {
print(' ' + k + ' = ' + obj[k]);
}
print('}');
}
function arrayrepr(array) {
return '[' + array.join(', ') + ']';
}
function assertArrayEquals(array1, array2) {
if (array1.length != array2.length) {
throw new crosscheck.AssertionFailure(array1.join(', ') + ' != ' + array2.join(', '));
}
for (var i=0; i<array1.length; i++) {
if (array1[i] != array2[i]) {
throw new crosscheck.AssertionFailure(arrayrepr(array1) + ' and ' + arrayrepr(array2)
+ ' differs at index ' + i);
}
}
}