lambda: do not distinguish between ellipsis and arrays for formal lambda params checks (IDEA-117124)

(cherry picked from commit 03b253b084ddb93ce485b1997d47a4b00284eb74)

java/java-analysis-impl/src/com/intellij/codeInsight/daemon/impl/analysis/HighlightVisitorImpl.java

@@ -314,7 +314,7 @@ public class HighlightVisitorImpl extends JavaElementVisitor implements Highligh
                     final PsiSubstitutor substitutor = LambdaUtil.getSubstitutor(interfaceMethod, resolveResult);
                     if (expression.hasFormalParameterTypes()) {
                       for (int i = 0; i < lambdaParameters.length; i++) {
-                        if (!Comparing.equal(lambdaParameters[i].getType(), substitutor.substitute(parameters[i].getType()))) {
+                        if (!PsiTypesUtil.compareTypes(lambdaParameters[i].getType(), substitutor.substitute(parameters[i].getType()), true)) {
                           HighlightInfo result = HighlightInfo.newHighlightInfo(HighlightInfoType.ERROR)
                             .range(lambdaParameters[i])
                             .descriptionAndTooltip(incompatibleTypesMessage)

java/java-psi-api/src/com/intellij/psi/util/PsiTypesUtil.java

@@ -17,6 +17,7 @@ package com.intellij.psi.util;
 
 import com.intellij.lang.ASTNode;
 import com.intellij.openapi.project.Project;
+import com.intellij.openapi.util.Comparing;
 import com.intellij.openapi.util.Condition;
 import com.intellij.pom.java.LanguageLevel;
 import com.intellij.psi.*;
@@ -215,4 +216,16 @@ public class PsiTypesUtil {
     }
     return null;
   }
+  
+  public static boolean compareTypes(PsiType leftType, PsiType rightType, boolean ignoreEllipsis) {
+    if (ignoreEllipsis) {
+      if (leftType instanceof PsiEllipsisType) {
+        leftType = ((PsiEllipsisType)leftType).toArrayType();
+      }
+      if (rightType instanceof PsiEllipsisType) {
+        rightType = ((PsiEllipsisType)rightType).toArrayType();
+      }
+    }
+    return Comparing.equal(leftType, rightType);
+  }
 }

java/java-tests/testData/codeInsight/daemonCodeAnalyzer/lambda/newLambda/Ellipsis.java

@@ -0,0 +1,9 @@
+interface Var {
+    void var(int... ps);
+}
+
+class Abc {
+    void foo() {
+        Var var = (int[] ps) -> {};
+    }
+}

java/java-tests/testSrc/com/intellij/codeInsight/daemon/lambda/NewLambdaHighlightingTest.java

@@ -86,6 +86,10 @@ public class NewLambdaHighlightingTest extends LightDaemonAnalyzerTestCase {
     doTest();
   }
 
+  public void testEllipsis() throws Exception {
+    doTest();
+  }
+
   private void doTest() {
     doTest(false);
   }