KT-3574 Assertion error when using ?: in for range

#KT-3574 Fixed

Do not assert that resolvedCall is non-null, since getRangeAsBinaryCall can
return a BinaryCall that doesn't represent a range at all (as specified by the
comment in getRangeAsBinaryCall)

compiler/backend/src/org/jetbrains/jet/codegen/ExpressionCodegen.java

@@ -466,12 +466,11 @@ public class ExpressionCodegen extends JetVisitor<StackValue, StackValue> implem
         RangeCodegenUtil.BinaryCall binaryCall = RangeCodegenUtil.getRangeAsBinaryCall(forExpression);
         if (binaryCall != null) {
             ResolvedCall<? extends CallableDescriptor> resolvedCall = bindingContext.get(RESOLVED_CALL, binaryCall.op);
-            assert resolvedCall != null;
-
-            CallableDescriptor rangeTo = resolvedCall.getResultingDescriptor();
-            if (RangeCodegenUtil.isOptimizableRangeTo(rangeTo)) {
-                generateForLoop(new ForInRangeLiteralLoopGenerator(forExpression, binaryCall));
-                return StackValue.none();
+            if (resolvedCall != null) {
+                if (RangeCodegenUtil.isOptimizableRangeTo(resolvedCall.getResultingDescriptor())) {
+                    generateForLoop(new ForInRangeLiteralLoopGenerator(forExpression, binaryCall));
+                    return StackValue.none();
+                }
             }
         }
 

compiler/testData/codegen/box/controlStructures/kt3574.kt

@@ -0,0 +1,9 @@
+fun nil() = null
+
+fun list() = java.util.Arrays.asList("1")
+
+fun box(): String {
+    for (x in nil()?:list()) {
+    }
+    return "OK"
+}

compiler/tests/org/jetbrains/jet/codegen/generated/BlackBoxCodegenTestGenerated.java

@@ -1436,6 +1436,11 @@ public class BlackBoxCodegenTestGenerated extends AbstractBlackBoxCodegenTest {
             doTest("compiler/testData/codegen/box/controlStructures/kt3280.kt");
         }
         
+        @TestMetadata("kt3574.kt")
+        public void testKt3574() throws Exception {
+            doTest("compiler/testData/codegen/box/controlStructures/kt3574.kt");
+        }
+        
         @TestMetadata("kt416.kt")
         public void testKt416() throws Exception {
             doTest("compiler/testData/codegen/box/controlStructures/kt416.kt");