fixed bug in renderer for violated upper bound error

compiler/frontend/src/org/jetbrains/jet/lang/diagnostics/rendering/Renderers.java

@@ -267,7 +267,8 @@ public class Renderers {
 
         TypeParameterDescriptor typeParameterDescriptor = null;
         ConstraintSystemImpl constraintSystem = (ConstraintSystemImpl) inferenceErrorData.constraintSystem;
-        assert constraintSystem.getStatus().hasViolatedUpperBound();
+        ConstraintSystemStatus status = constraintSystem.getStatus();
+        assert status.hasViolatedUpperBound();
 
         ConstraintSystem systemWithoutWeakConstraints = constraintSystem.getSystemWithoutWeakConstraints();
         for (TypeParameterDescriptor typeParameter : inferenceErrorData.descriptor.getTypeParameters()) {
@@ -275,6 +276,9 @@ public class Renderers {
                 typeParameterDescriptor = typeParameter;
             }
         }
+        if (typeParameterDescriptor == null && status.hasConflictingConstraints()) {
+            return renderConflictingSubstitutionsInferenceError(inferenceErrorData, result);
+        }
         assert typeParameterDescriptor != null : errorMessage;
 
         JetType inferredValueForTypeParameter = systemWithoutWeakConstraints.getTypeBounds(typeParameterDescriptor).getValue();

compiler/testData/diagnostics/tests/inference/upperBounds/conflictingSubstitutionsFromUpperBound.kt

@@ -0,0 +1,10 @@
+package g
+
+import java.util.HashSet
+fun <T, C: Collection<T>> convert(src: Collection<T>, dest: C): C = throw Exception("$src $dest")
+
+fun test(l: List<Int>) {
+    //todo should be inferred
+    val r = <!TYPE_INFERENCE_UPPER_BOUND_VIOLATED!>convert<!>(l, <!TYPE_INFERENCE_NO_INFORMATION_FOR_PARAMETER!>HashSet<!>())
+    <!DEBUG_INFO_ELEMENT_WITH_ERROR_TYPE!>r<!>: Int
+}

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

@@ -3907,6 +3907,11 @@ public class JetDiagnosticsTestGenerated extends AbstractJetDiagnosticsTest {
                     JetTestUtils.assertAllTestsPresentByMetadata(this.getClass(), "org.jetbrains.jet.generators.tests.TestsPackage", new File("compiler/testData/diagnostics/tests/inference/upperBounds"), Pattern.compile("^(.+)\\.kt$"), true);
                 }
                 
+                @TestMetadata("conflictingSubstitutionsFromUpperBound.kt")
+                public void testConflictingSubstitutionsFromUpperBound() throws Exception {
+                    doTest("compiler/testData/diagnostics/tests/inference/upperBounds/conflictingSubstitutionsFromUpperBound.kt");
+                }
+                
                 @TestMetadata("doNotInferFromBoundsOnly.kt")
                 public void testDoNotInferFromBoundsOnly() throws Exception {
                     doTest("compiler/testData/diagnostics/tests/inference/upperBounds/doNotInferFromBoundsOnly.kt");

core/descriptors/src/org/jetbrains/jet/renderer/DescriptorRendererImpl.java

@@ -36,6 +36,7 @@ import java.util.*;
 
 import static org.jetbrains.jet.lang.types.TypeUtils.CANT_INFER_LAMBDA_PARAM_TYPE;
 import static org.jetbrains.jet.lang.types.TypeUtils.CANT_INFER_TYPE_PARAMETER;
+import static org.jetbrains.jet.lang.types.TypeUtils.DONT_CARE;
 
 public class DescriptorRendererImpl implements DescriptorRenderer {
     private final boolean shortNames;
@@ -213,7 +214,7 @@ public class DescriptorRendererImpl implements DescriptorRenderer {
     }
 
     private String renderTypeWithoutEscape(@NotNull JetType type) {
-        if (type == CANT_INFER_LAMBDA_PARAM_TYPE || type == CANT_INFER_TYPE_PARAMETER) {
+        if (type == CANT_INFER_LAMBDA_PARAM_TYPE || type == CANT_INFER_TYPE_PARAMETER || type == DONT_CARE) {
             return "???";
         }
         if (type.isError()) {