Add ExprAggregate as a negative edge in getConjunctionParentRec

Author: atorralba

ql/ql/src/codeql_ql/style/ConjunctionParent.qll

@@ -28,6 +28,7 @@ module ConjunctionParent<checkAstNodeSig/1 checkAstNode> {
     not result instanceof Implication and
     not result instanceof Negation and
     not result instanceof Predicate and
+    not result instanceof ExprAggregate and
     not result instanceof FullAggregate and
     not result instanceof Forex and
     not result instanceof Forall

ql/ql/test/queries/style/OmittableExists/OmittableExists.expected

@@ -1 +1 @@
-| Test.qll:18:10:18:14 | i | This exists variable can be omitted by using a don't-care expression $@. | Test.qll:18:29:18:29 | i | in this argument |
+| Test.qll:20:10:20:14 | i | This exists variable can be omitted by using a don't-care expression $@. | Test.qll:20:29:20:29 | i | in this argument |

ql/ql/test/queries/style/OmittableExists/Test.qll

@@ -6,6 +6,8 @@ predicate yetAnotherPredicate(int i, int y) { none() }
 
 predicate dbTypePredicate(@location l) { none() }
 
+string predicateWithResult(int i) { none() }
+
 class SmallInt extends int {
   SmallInt() { this = [0 .. 10] }
 }
@@ -23,6 +25,8 @@ predicate test() {
   or
   exists(int i | aPredicate(i) and exists(int i2 | i = i2)) // GOOD
   or
+  exists(int i | count(predicateWithResult(i)) = 0) // GOOD
+  or
   exists(int i | count(int y | yetAnotherPredicate(i, y)) > 0) // GOOD
   or
   exists(int i | forex(int y | yetAnotherPredicate(i, y))) // GOOD