change signature: fix reorder & making varargs at one step (IDEA-153052)

java/java-impl/src/com/intellij/refactoring/changeSignature/JavaChangeInfoImpl.java

@@ -186,9 +186,10 @@ public class JavaChangeInfoImpl extends UserDataHolderBase implements JavaChange
     }
     else {
       final ParameterInfoImpl lastNewParm = this.newParms[this.newParms.length - 1];
-      obtainsVarags = lastNewParm.isVarargType();
-      retainsVarargs = lastNewParm.oldParameterIndex >= 0 && obtainsVarags;
-      arrayToVarargs = retainsVarargs && oldParameterTypes[lastNewParm.oldParameterIndex].endsWith("[]");
+      boolean isVarargs = lastNewParm.isVarargType();
+      obtainsVarags = isVarargs && lastNewParm.oldParameterIndex < 0;
+      retainsVarargs = lastNewParm.oldParameterIndex >= 0 && oldParameterTypes[lastNewParm.oldParameterIndex].endsWith("...") && isVarargs;
+      arrayToVarargs = lastNewParm.oldParameterIndex >= 0 && oldParameterTypes[lastNewParm.oldParameterIndex].endsWith("[]") && isVarargs;
     }
 
     if (isNameChanged) {

java/java-tests/testData/refactoring/changeSignature/ReorderWithVarargsFromSimpleType.java

@@ -0,0 +1,7 @@
+class Test {
+    void <caret>foo(String[] s, int a) {}
+
+    {
+        foo("a", 1);
+    }
+}

java/java-tests/testData/refactoring/changeSignature/ReorderWithVarargsFromSimpleType_after.java

@@ -0,0 +1,7 @@
+class Test {
+    void foo(int a, String... s) {}
+
+    {
+        foo(1, "a");
+    }
+}

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

@@ -357,6 +357,13 @@ public class ChangeSignatureTest extends ChangeSignatureBaseTest {
     }, false);
   }
 
+  public void testReorderWithVarargsFromSimpleType() {
+    doTest(null, new ParameterInfoImpl[]{
+      new ParameterInfoImpl(1),
+      new ParameterInfoImpl(0, "s", myFactory.createTypeFromText("java.lang.String...", getFile()))
+    }, false);
+  }
+
   public void testIntroduceParameterWithDefaultValueInHierarchy() {
     doTest(null, new ParameterInfoImpl[]{new ParameterInfoImpl(-1, "i", PsiType.INT, "0")}, false);
   }