CSHARP-1734: fixing issue related to nested Any clauses with conjunctions.

Author: craiggwilson

src/MongoDB.Driver/Linq/Translators/PredicateTranslator.cs

@@ -1628,6 +1628,11 @@ protected internal override Expression VisitDocument(DocumentExpression node)
             {
                 return new FieldExpression("", node.Serializer);
             }
+
+            protected internal override Expression VisitPipeline(PipelineExpression node)
+            {
+                return node;
+            }
         }
     }
 }

tests/MongoDB.Driver.Tests/Linq/Translators/PredicateTranslatorTests.cs

@@ -135,6 +135,16 @@ public void Any_with_a_nested_Any()
                 x => x.G.Any(g => g.S.Any(s => s.D == "Delilah")),
                 1,
                 "{\"G.S.D\": \"Delilah\"}");
+
+            Assert(
+                x => x.G.Any(g => g.D == "Don't" && g.S.Any(s => s.D == "Delilah")),
+                1,
+                "{G: {$elemMatch: {D: \"Don't\", \"S.D\": \"Delilah\" }}}");
+
+            Assert(
+                x => x.G.Any(g => g.D == "Don't" && g.S.Any(s => s.E == null && s.D == "Delilah")),
+                1,
+                "{G: {$elemMatch: {D: \"Don't\", \"S\": {$elemMatch: {E: null, D: \"Delilah\" }}}}}");
         }
 
         [Fact]