fix spurious resolved predicate expressions

Author: erik-krogh

ql/ql/src/codeql_ql/ast/internal/Predicate.qll

@@ -49,7 +49,8 @@ private module Cached {
       m = pe.getQualifier().getResolvedModule() and
       public = true
     |
-      definesPredicate(m, pe.getName(), p.getArity(), p, public)
+      definesPredicate(m, pe.getName(), p.getArity(), p, public) and
+      p.getArity() = pe.getArity()
     )
   }
 
@@ -200,7 +201,12 @@ module PredConsistency {
   }
 
   query predicate multipleResolvePredicateExpr(PredicateExpr pe, int c, ClasslessPredicate p) {
-    c = strictcount(ClasslessPredicate p0 | resolvePredicateExpr(pe, p0)) and
+    c =
+      strictcount(ClasslessPredicate p0 |
+        resolvePredicateExpr(pe, p0) and
+        // aliases are expected to resolve to multiple.
+        not exists(p0.(ClasslessPredicate).getAlias())
+      ) and
     c > 1 and
     resolvePredicateExpr(pe, p)
   }

ql/ql/src/queries/diagnostics/EmptyConsistencies.ql

@@ -24,6 +24,9 @@ where
   or
   PredConsistency::multipleResolveCall(node, _, _) and msg = "PredConsistency::multipleResolveCall"
   or
+  PredConsistency::multipleResolvePredicateExpr(node, _, _) and
+  msg = "PredConsistency::multipleResolvePredicateExpr"
+  or
   TypeConsistency::exprNoType(node) and msg = "TypeConsistency::exprNoType"
   or
   TypeConsistency::varDefNoType(node) and msg = "TypeConsistency::varDefNoType"

ql/ql/test/callgraph/callgraph.expected

@@ -49,6 +49,5 @@ exprPredicate
 | Foo.qll:47:55:47:62 | predicate | Foo.qll:42:20:42:27 | NewTypeBranch MkRoot |
 | Foo.qll:47:65:47:70 | predicate | Foo.qll:44:9:44:56 | ClasslessPredicate edge |
 | MultiResolve.qll:12:19:12:23 | predicate | MultiResolve.qll:1:1:4:1 | ClasslessPredicate foo |
-| MultiResolve.qll:12:19:12:23 | predicate | MultiResolve.qll:6:1:10:1 | ClasslessPredicate foo |
 | ParamModules.qll:4:18:4:25 | predicate | ParamModules.qll:2:13:2:36 | ClasslessPredicate fooSig |
 | ParamModules.qll:10:34:10:40 | predicate | ParamModules.qll:8:3:8:35 | ClasslessPredicate myFoo |