KT-597 Type inference failed

Resolution rules changed: now autocast and non-autocast candidates are judged together

compiler/frontend/src/org/jetbrains/jet/lang/resolve/calls/TaskPrioritizer.java

@@ -64,20 +64,8 @@ import static org.jetbrains.jet.lang.resolve.scopes.receivers.ReceiverDescriptor
             scope = explicitReceiver.getType().getMemberScope();
             explicitReceiver = NO_RECEIVER;
         }
-        doComputeTasks(scope, explicitReceiver, call, name, result, AutoCastService.NO_AUTO_CASTS);
+        doComputeTasks(scope, explicitReceiver, call, name, result, new AutoCastServiceImpl(dataFlowInfo, bindingContext));
 
-        List<ReceiverDescriptor> receivers;
-        if (explicitReceiver.exists()) {
-            receivers = Collections.singletonList(explicitReceiver);
-        }
-        else {
-            receivers = Lists.newArrayList();
-            scope.getImplicitReceiversHierarchy(receivers);
-        }
-        for (ReceiverDescriptor receiverToCast : receivers) {
-            assert receiverToCast.exists();
-            doComputeTasks(scope, receiverToCast, call, name, result, new AutoCastServiceImpl(dataFlowInfo, bindingContext));
-        }
         return result;
     }
 
@@ -87,7 +75,7 @@ import static org.jetbrains.jet.lang.resolve.scopes.receivers.ReceiverDescriptor
         scope.getImplicitReceiversHierarchy(implicitReceivers);
         if (receiver.exists()) {
             List<ReceiverDescriptor> variantsForExplicitReceiver = autoCastService.getVariantsForReceiver(receiver);
-
+            
             Collection<ResolvedCallImpl<D>> extensionFunctions = convertWithImpliedThis(scope, variantsForExplicitReceiver, getExtensionsByName(scope, name));
             List<ResolvedCallImpl<D>> nonlocals = Lists.newArrayList();
             List<ResolvedCallImpl<D>> locals = Lists.newArrayList();

compiler/frontend/src/org/jetbrains/jet/lang/resolve/calls/autocasts/AutoCastServiceImpl.java

@@ -1,5 +1,6 @@
 package org.jetbrains.jet.lang.resolve.calls.autocasts;
 
+import com.google.common.collect.Lists;
 import org.jetbrains.annotations.NotNull;
 import org.jetbrains.jet.lang.resolve.BindingContext;
 import org.jetbrains.jet.lang.resolve.scopes.receivers.ReceiverDescriptor;
@@ -21,7 +22,9 @@ public class AutoCastServiceImpl implements AutoCastService {
     @NotNull
     @Override
     public List<ReceiverDescriptor> getVariantsForReceiver(@NotNull ReceiverDescriptor receiverDescriptor) {
-        return AutoCastUtils.getAutoCastVariants(bindingContext, dataFlowInfo, receiverDescriptor);
+        List<ReceiverDescriptor> variants = Lists.newArrayList(AutoCastUtils.getAutoCastVariants(bindingContext, dataFlowInfo, receiverDescriptor));
+        variants.add(receiverDescriptor);
+        return variants;
     }
 
     @NotNull

compiler/frontend/src/org/jetbrains/jet/lang/resolve/calls/autocasts/AutoCastUtils.java

@@ -17,6 +17,9 @@ public class AutoCastUtils {
 
     private AutoCastUtils() {}
 
+    /**
+     * @return variants @param receiverToCast may be cast to according to @param dataFlowInfo, @param receiverToCast itself is NOT included
+     */
     public static List<ReceiverDescriptor> getAutoCastVariants(@NotNull final BindingContext bindingContext, @NotNull final DataFlowInfo dataFlowInfo, @NotNull ReceiverDescriptor receiverToCast) {
         return receiverToCast.accept(new ReceiverDescriptorVisitor<List<ReceiverDescriptor>, Object>() {
             @Override

compiler/frontend/src/org/jetbrains/jet/lang/resolve/calls/autocasts/DataFlowInfo.java

@@ -102,7 +102,7 @@ public class DataFlowInfo {
 
         boolean changed = false;
         changed |= putNullability(builder, a, nullabilityOfA.refine(nullabilityOfB.invert()));
-        changed |= putNullability(builder, b, nullabilityOfA.refine(nullabilityOfA.invert()));
+        changed |= putNullability(builder, b, nullabilityOfB.refine(nullabilityOfA.invert()));
         return changed ? new DataFlowInfo(ImmutableMap.copyOf(builder), typeInfo) : this;
     }
 

compiler/testData/checkerWithErrorTypes/quick/regressions/kt597.jet

@@ -0,0 +1,20 @@
+//KT-597 Type inference failed
+// +JDK
+
+fun <T> Array<T>?.get(i: Int) : T {
+    if (this != null)
+        return this.get(i) // <- inferred type is Any? but &T was excepted
+    else throw NullPointerException()
+}
+
+fun Int?.inc() : Int {
+    if (this != null)
+        return this.inc()
+    else
+        throw NullPointerException()
+}
+
+fun test() {
+   var i : Int? = 10
+   var <!UNUSED_VARIABLE!>i_inc<!> = <!UNUSED_CHANGED_VALUE!>i++<!> // <- expected Int?, but returns Any?
+}

idea/testData/checker/infos/Autocasts.jet

@@ -216,7 +216,7 @@ fun declarationInsidePattern(x: (Any, Any)): String = when(x) { is (val a is Str
 fun mergeAutocasts(a: Any?) {
   if (a is String || a is Int) {
     a.<error descr="Unresolved reference: compareTo">compareTo</error>("")
-    a.toString()
+    <info descr="Automatically cast to Any">a</info>.toString()
   }
   if (a is Int || a is String) {
     a.<error descr="Unresolved reference: compareTo">compareTo</error>("")