new inference: most specific check according to spec, fixed testdata after JDK-8043734

java/java-psi-impl/src/com/intellij/psi/impl/source/resolve/graphInference/InferenceSession.java

@@ -1205,9 +1205,6 @@ public class InferenceSession {
       }
 
       final List<PsiExpression> returnExpressions = LambdaUtil.getReturnExpressions((PsiLambdaExpression)arg);
-      if (sReturnType == PsiType.VOID) {
-        return returnExpressions.isEmpty() && session == null;
-      }
 
       if (LambdaUtil.isFunctionalType(sReturnType) && LambdaUtil.isFunctionalType(tReturnType) && 
           !TypeConversionUtil.isAssignable(TypeConversionUtil.erasure(sReturnType), TypeConversionUtil.erasure(tReturnType)) &&
@@ -1263,10 +1260,6 @@ public class InferenceSession {
         return true;
       }
 
-      if (sReturnType == PsiType.VOID && session != null) {
-        return false;
-      }
-
       final boolean sPrimitive = sReturnType instanceof PsiPrimitiveType && sReturnType != PsiType.VOID;
       final boolean tPrimitive = tReturnType instanceof PsiPrimitiveType && tReturnType != PsiType.VOID;
 

java/java-tests/testData/codeInsight/daemonCodeAnalyzer/lambda/highlighting/Ambiguity1.java

@@ -12,7 +12,7 @@ class Ambiguity1 {
   static <T> void m(I2<T> i2) {}
 
   {
-    m<error descr="Ambiguous method call: both 'Ambiguity1.m(I1)' and 'Ambiguity1.m(I2<Object>)' match">(()->{throw new AssertionError();})</error>;
+    m(()->{throw new AssertionError();});
     m(() -> {});
     m(() -> {
         if (false) return;

java/java-tests/testData/codeInsight/daemonCodeAnalyzer/lambda/highlighting/AmbiguityRawGenerics.java

@@ -22,6 +22,6 @@ class AmbiguityRawGenerics {
     <Z> void foo(I3<Z> s) { }
 
     void bar() {
-        foo<error descr="Ambiguous method call: both 'AmbiguityRawGenerics.foo(I)' and 'AmbiguityRawGenerics.foo(I1)' match">(()-> { throw new RuntimeException(); })</error>;
+        foo<error descr="Ambiguous method call: both 'AmbiguityRawGenerics.foo(I1)' and 'AmbiguityRawGenerics.foo(I2)' match">(()-> { throw new RuntimeException(); })</error>;
     }
 }

java/java-tests/testData/codeInsight/daemonCodeAnalyzer/lambda/mostSpecific/NoReturnTypeResolutionForThrownException.java

@@ -7,7 +7,7 @@ class Test {
   void call(I2 p) { }
  
   void test() {
-    call<error descr="Ambiguous method call: both 'Test.call(I1)' and 'Test.call(I2)' match">(() -> { throw new RuntimeException(); })</error>;
+    call(() -> { throw new RuntimeException(); });
     call(() -> { if (true) return ""; throw new RuntimeException(); });
     call(() -> { if (true) return; throw new RuntimeException(); });
   }