mongodb/mongo-csharp-driver — pull request #193 by carducci (2014-10-28 16:00:28+00:00)
Title: The query builder was generating invalid queries when ANDing two or more

conditions that both exist in a in an array of objects.

Assuming a document like this
{
_objectid:...,
Item:555,
MetaData: [{
Foo: Bar
},
{
Baz: Bat
}]...
}
Query.And with two conditons in that array would generate invalid syntax.
I found the solution was to promote to $and everytime. There is certainly
a more elegant solution, but this solved my immediate problem with no ill
effects.