fix #1668 (#1688)

Author: Andrin Meier

Rubberduck.Parsing/Symbols/IdentifierReferenceResolver.cs

@@ -550,44 +550,42 @@ public void Resolve(VBAParser.AsTypeClauseContext context)
 
         public void Resolve(VBAParser.ForNextStmtContext context)
         {
+            // In "For expr1 = expr2" the "expr1 = expr2" part is treated as a single expression.
+            var assignmentExpr = ((VBAParser.RelationalOpContext)context.expression()[0]);
+            var lExpr = assignmentExpr.expression()[0];
             var firstExpression = _bindingService.ResolveDefault(
                 _moduleDeclaration,
                 _currentParent,
-                context.expression()[0],
+                lExpr,
                 GetInnerMostWithExpression(),
                 StatementResolutionContext.Undefined);
-            if (firstExpression.Classification == ExpressionClassification.ResolutionFailed)
-            {
-                _boundExpressionVisitor.AddIdentifierReferences(
-                    firstExpression,
-                    _qualifiedModuleName,
-                    _currentScope,
-                    _currentParent);
-            }
-            else
+            _boundExpressionVisitor.AddIdentifierReferences(
+                firstExpression,
+                _qualifiedModuleName,
+                _currentScope,
+                _currentParent);
+            if (firstExpression.Classification != ExpressionClassification.ResolutionFailed)
             {
-                // In "For expr1 = expr2" the "expr1 = expr2" part is treated as a single expression.
-                var binOp = (BinaryOpExpression)firstExpression;
-                var assignmentExpr = binOp.Left;
-                var fromExpr = binOp.Right;
                 // each iteration counts as an assignment
                 _boundExpressionVisitor.AddIdentifierReferences(
-                    assignmentExpr,
+                    firstExpression,
                     _qualifiedModuleName,
                     _currentScope,
                     _currentParent,
                     true);
-                _boundExpressionVisitor.AddIdentifierReferences(
-                    assignmentExpr,
-                    _qualifiedModuleName,
-                    _currentScope,
-                    _currentParent);
-                _boundExpressionVisitor.AddIdentifierReferences(
-                    fromExpr,
-                    _qualifiedModuleName,
-                    _currentScope,
-                    _currentParent);
             }
+            var rExpr = assignmentExpr.expression()[1];
+            var secondExpression = _bindingService.ResolveDefault(
+                _moduleDeclaration,
+                _currentParent,
+                rExpr,
+                GetInnerMostWithExpression(),
+                StatementResolutionContext.Undefined);
+            _boundExpressionVisitor.AddIdentifierReferences(
+                secondExpression,
+                _qualifiedModuleName,
+                _currentScope,
+                _currentParent);
             for (int exprIndex = 1; exprIndex < context.expression().Count; exprIndex++)
             {
                 ResolveDefault(context.expression()[exprIndex]);

RubberduckTests/Grammar/ResolverTests.cs

@@ -752,6 +752,30 @@ End Sub
                 && item.IsAssignment));
         }
 
+        [TestMethod]
+        public void ForLoop_AddsReferenceEvenIfAssignmentResolutionFailure()
+        {
+            // arrange
+            var code = @"
+Public Sub DoSomething()
+    Dim i As Integer
+    For i = doesntExist To doesntExistEither
+    Next
+End Sub
+";
+            // act
+            var state = Resolve(code);
+
+            // assert
+            var declaration = state.AllUserDeclarations.Single(item =>
+                item.DeclarationType == DeclarationType.Variable && item.IdentifierName == "i");
+
+            Assert.IsNotNull(declaration.References.SingleOrDefault(item =>
+                item.ParentScoping.DeclarationType == DeclarationType.Procedure
+                && item.ParentScoping.IdentifierName == "DoSomething"
+                && item.IsAssignment));
+        }
+
         [TestMethod]
         public void ForEachLoop_IsReferenceToIteratorDeclaration()
         {