suggest functional: ensure only exact types are suggested for primitives

SAM types with primitive parameters should be checked for exact matching, boxed types accept passing primitives

java/java-impl/src/com/intellij/codeInsight/FunctionalInterfaceSuggester.java

@@ -106,7 +106,10 @@ public class FunctionalInterfaceSuggester {
         }
 
         for (int i = 0; i < interfaceMethodParameters.length; i++) {
-          if (!TypeConversionUtil.isAssignable(parameters[i].getType(), substitutor.substitute(interfaceMethodParameters[i].getType()))) {
+          PsiType paramType = parameters[i].getType();
+          PsiType interfaceParamType = substitutor.substitute(interfaceMethodParameters[i].getType());
+          if (!(interfaceParamType instanceof PsiPrimitiveType
+                ? paramType.equals(interfaceParamType) : TypeConversionUtil.isAssignable(paramType, interfaceParamType))) {
             return null;
           }
         }
@@ -117,7 +120,7 @@ public class FunctionalInterfaceSuggester {
           return null;
         }
         
-        if (returnType instanceof PsiPrimitiveType && !returnType.equals(interfaceMethodReturnType)) {
+        if (interfaceMethodReturnType instanceof PsiPrimitiveType && !interfaceMethodReturnType.equals(returnType)) {
           return null;
         }
 

java/java-tests/testSrc/com/intellij/java/refactoring/FunctionalInterfaceSuggesterTest.java

@@ -39,8 +39,8 @@ public class FunctionalInterfaceSuggesterTest extends LightCodeInsightFixtureTes
       .stream()
       .map(type -> type.getCanonicalText())
       .collect(Collectors.toList());
-    Assert.assertTrue(suggestedTypes.containsAll(Arrays.asList("java.util.function.IntToDoubleFunction", 
+    Assert.assertEquals(4, suggestedTypes.size());
+    Assert.assertTrue(suggestedTypes.containsAll(Arrays.asList("java.util.function.ToDoubleFunction<java.lang.Double>",
                                                                "java.util.function.DoubleUnaryOperator")));
-    Assert.assertFalse(suggestedTypes.contains("java.util.function.LongToIntFunction"));
   }
 }