KT-2841 Can't infer a type for function literal parameter if the return type is error

#KT-2841 fixed

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

@@ -378,9 +378,7 @@ public class CallResolver {
 
 
         if (!constraintSystem.isSuccessful()) {
-            if (constraintSystemWithoutExpectedTypeConstraint.isSuccessful()) {
+            resolvedCall.setResultingSubstitutor(constraintSystemWithoutExpectedTypeConstraint.getResultingSubstitutor());
-                resolvedCall.setResultingSubstitutor(constraintSystemWithoutExpectedTypeConstraint.getResultingSubstitutor());
-            }
             List<JetType> argumentTypes = checkValueArgumentTypes(context, resolvedCall, resolvedCall.getTrace()).argumentTypes;
             JetType receiverType = resolvedCall.getReceiverArgument().exists() ? resolvedCall.getReceiverArgument().getType() : null;
             context.tracing.typeInferenceFailed(resolvedCall.getTrace(),

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

@@ -40,6 +40,7 @@ import static org.jetbrains.jet.lang.types.Variance.*;
 public class ConstraintSystemImpl implements ConstraintSystem {
 
     public static final JetType DONT_CARE = ErrorUtils.createErrorTypeWithCustomDebugName("DONT_CARE");
+    private static final JetType CANT_INFER = ErrorUtils.createErrorType("CANT_INFER");
 
     private final Map<TypeParameterDescriptor, TypeConstraintsImpl> typeParameterConstraints = Maps.newLinkedHashMap();
     private final Set<ConstraintPosition> errorConstraintPositions = Sets.newHashSet();
@@ -48,7 +49,7 @@ public class ConstraintSystemImpl implements ConstraintSystem {
     private boolean hasErrorInConstrainingTypes;
 
     public ConstraintSystemImpl() {
-        this.resultingSubstitutor = createTypeSubstitutorWithDefaultForUnknownTypeParameter(null);
+        this.resultingSubstitutor = createTypeSubstitutorWithDefaultForUnknownTypeParameter(new TypeProjection(CANT_INFER));
         this.currentSubstitutor = createTypeSubstitutorWithDefaultForUnknownTypeParameter(new TypeProjection(DONT_CARE));
     }
 
@@ -154,16 +155,20 @@ public class ConstraintSystemImpl implements ConstraintSystem {
             @Nullable JetType constrainingType,
             @NotNull ConstraintPosition constraintPosition) {
 
-        if (constrainingType == null || (ErrorUtils.isErrorType(constrainingType) && constrainingType != DONT_CARE)) {
+        if (constrainingType == TypeUtils.NO_EXPECTED_TYPE
+            || TypeUtils.identityEqualsOrContainsAsArgument(constrainingType, DONT_CARE)
+            || TypeUtils.identityEqualsOrContainsAsArgument(constrainingType, CANT_INFER)) {
+            return;
+        }
+
+        if (constrainingType == null || ErrorUtils.containsErrorType(constrainingType)) {
             hasErrorInConstrainingTypes = true;
             return;
         }
 
         assert subjectType != TypeUtils.NO_EXPECTED_TYPE : "Subject type shouldn't be NO_EXPECTED_TYPE (in position " + constraintPosition + " )";
+        if (ErrorUtils.isErrorType(subjectType)) return;
 
-        if (constrainingType == DONT_CARE || ErrorUtils.isErrorType(subjectType) || constrainingType == TypeUtils.NO_EXPECTED_TYPE) {
-            return;
-        }
 
         DeclarationDescriptor constrainingTypeDescriptor = constrainingType.getConstructor().getDeclarationDescriptor();
         DeclarationDescriptor subjectTypeDescriptor = subjectType.getConstructor().getDeclarationDescriptor();

compiler/frontend/src/org/jetbrains/jet/lang/types/TypeUtils.java

@@ -472,4 +472,14 @@ public class TypeUtils {
         }
         return false;
     }
+
+    public static boolean identityEqualsOrContainsAsArgument(@Nullable JetType type, @NotNull JetType argumentType) {
+        if (type == null) return false;
+        if (type == argumentType) return true;
+        if (type instanceof NamespaceType) return false;
+        for (TypeProjection projection : type.getArguments()) {
+            if (identityEqualsOrContainsAsArgument(projection.getType(), argumentType)) return true;
+        }
+        return false;
+    }
 }

compiler/testData/diagnostics/tests/inference/regressions/kt2841.kt

@@ -0,0 +1,15 @@
+package a
+
+trait Closeable {}
+class C : Closeable {}
+
+public inline fun <T: Closeable, R> T.use1(block: (T)-> R) : R {
+    return block(this)
+}
+
+fun main(args: Array<String>) {
+    C().<!TYPE_INFERENCE_NO_INFORMATION_FOR_PARAMETER!>use1<!> {
+        w ->  // ERROR here
+        <!UNRESOLVED_REFERENCE!>x<!>
+    }
+}

compiler/testData/diagnostics/tests/inference/regressions/kt2841_it.kt

@@ -0,0 +1,18 @@
+package a
+
+trait Closeable {
+    fun close() {}
+}
+
+class C : Closeable
+
+public inline fun <T: Closeable, R> T.use(block: (t: T)-> R) : R {
+    return block(this)
+}
+
+fun test() {
+    C().<!TYPE_INFERENCE_NO_INFORMATION_FOR_PARAMETER!>use<!> {
+        it.close()
+        <!UNRESOLVED_REFERENCE!>x<!>
+    }
+}

compiler/testData/diagnostics/tests/inference/regressions/kt2841_it_this.kt

@@ -0,0 +1,19 @@
+package a
+
+trait Closeable {
+    fun close() {}
+}
+
+class C : Closeable
+
+public inline fun <T: Closeable, R> use(t: T, block: T.(T)-> R) : R {
+    return t.block(t)
+}
+
+fun test() {
+    <!TYPE_INFERENCE_NO_INFORMATION_FOR_PARAMETER!>use<!>(C()) {
+        this.close()
+        it.close()
+        <!UNRESOLVED_REFERENCE!>xx<!>
+    }
+}

compiler/testData/diagnostics/tests/inference/regressions/kt2841_this.kt

@@ -0,0 +1,18 @@
+package a
+
+trait Closeable {
+    fun close() {}
+}
+
+class C : Closeable
+
+public inline fun <T: Closeable, R> T.use(block: T.()-> R) : R {
+    return this.block()
+}
+
+fun test() {
+    C().<!TYPE_INFERENCE_NO_INFORMATION_FOR_PARAMETER!>use<!> {
+        this.close()
+        <!UNRESOLVED_REFERENCE!>x<!>
+    }
+}

compiler/tests/org/jetbrains/jet/checkers/JetDiagnosticsTestGenerated.java

@@ -13,16 +13,18 @@
  * See the License for the specific language governing permissions and
  * limitations under the License.
  */
-
 package org.jetbrains.jet.checkers;
 
+import junit.framework.Assert;
 import junit.framework.Test;
 import junit.framework.TestSuite;
+
+import java.io.File;
 import org.jetbrains.jet.JetTestUtils;
 import org.jetbrains.jet.test.InnerTestClasses;
 import org.jetbrains.jet.test.TestMetadata;
 
-import java.io.File;
+import org.jetbrains.jet.checkers.AbstractDiagnosticsTestWithEagerResolve;
 
 /** This class is generated by {@link org.jetbrains.jet.checkers.AbstractDiagnosticsTestWithEagerResolve}. DO NOT MODIFY MANUALLY */
 @InnerTestClasses({JetDiagnosticsTestGenerated.Tests.class, JetDiagnosticsTestGenerated.Script.class})
@@ -1889,6 +1891,26 @@ public class JetDiagnosticsTestGenerated extends AbstractDiagnosticsTestWithEage
                     doTest("compiler/testData/diagnostics/tests/inference/regressions/kt2514.kt");
                 }
                 
+                @TestMetadata("kt2841.kt")
+                public void testKt2841() throws Exception {
+                    doTest("compiler/testData/diagnostics/tests/inference/regressions/kt2841.kt");
+                }
+                
+                @TestMetadata("kt2841_it.kt")
+                public void testKt2841_it() throws Exception {
+                    doTest("compiler/testData/diagnostics/tests/inference/regressions/kt2841_it.kt");
+                }
+                
+                @TestMetadata("kt2841_it_this.kt")
+                public void testKt2841_it_this() throws Exception {
+                    doTest("compiler/testData/diagnostics/tests/inference/regressions/kt2841_it_this.kt");
+                }
+                
+                @TestMetadata("kt2841_this.kt")
+                public void testKt2841_this() throws Exception {
+                    doTest("compiler/testData/diagnostics/tests/inference/regressions/kt2841_this.kt");
+                }
+                
                 @TestMetadata("kt2842.kt")
                 public void testKt2842() throws Exception {
                     doTest("compiler/testData/diagnostics/tests/inference/regressions/kt2842.kt");