Snapshot idea/138.1503 from git://git.jetbrains.org/idea/community.git

Change-Id: Ie01af1d8710ec0ff51d90301bda1a18b0b5c0faf

1 files changed, 20 insertions, 1 deletions

diff --git a/java/java-analysis-impl/src/com/intellij/codeInspection/dataFlow/ContractInference.java b/java/java-analysis-impl/src/com/intellij/codeInspection/dataFlow/ContractInference.java
index a1c908837ad0..bd207e58a0fe 100644
--- a/java/java-analysis-impl/src/com/intellij/codeInspection/dataFlow/ContractInference.java
+++ b/java/java-analysis-impl/src/com/intellij/codeInspection/dataFlow/ContractInference.java
@@ -71,7 +71,23 @@ class ContractInferenceInterpreter {
     if (statements.length == 1) {
       if (statements[0] instanceof PsiReturnStatement) {
         List<MethodContract> result = handleDelegation(((PsiReturnStatement)statements[0]).getReturnValue(), false);
-        if (result != null) return result;
+        if (result != null) {
+          PsiTypeElement typeElement = myMethod.getReturnTypeElement();
+          final boolean returningObject = typeElement == null || !(typeElement.getType() instanceof PsiClassType);
+          return ContainerUtil.findAll(result, new Condition<MethodContract>() {
+            @Override
+            public boolean value(MethodContract contract) {
+              if ((contract.returnValue == NULL_VALUE || contract.returnValue == NOT_NULL_VALUE) && returningObject) {
+                return false;
+              }
+              if ((contract.returnValue == TRUE_VALUE || contract.returnValue == FALSE_VALUE) && !returningObject) {
+                return false;
+              }
+
+              return true;
+            }
+          });
+        }
       }
       else if (statements[0] instanceof PsiExpressionStatement && ((PsiExpressionStatement)statements[0]).getExpression() instanceof PsiMethodCallExpression) {
         List<MethodContract> result = handleDelegation(((PsiExpressionStatement)statements[0]).getExpression(), false);
@@ -132,6 +148,9 @@ class ContractInferenceInterpreter {
                 }
                 else {
                   answer = withConstraint(answer, paramIndex, argConstraint);
+                  if (answer == null) {
+                    return null;
+                  }
                 }
               }
             }