IG: highlight constructor call problems too (IDEA-173852)

plugins/InspectionGadgets/InspectionGadgetsAnalysis/src/com/siyeh/ig/bugs/NullArgumentToVariableArgMethodInspection.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2003-2016 Dave Griffith, Bas Leijdekkers
+ * Copyright 2003-2017 Dave Griffith, Bas Leijdekkers
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -83,9 +83,12 @@ public class NullArgumentToVariableArgMethodInspection extends BaseInspection {
   private static class NullArgumentToVariableArgVisitor extends BaseInspectionVisitor {
 
     @Override
-    public void visitMethodCallExpression(@NotNull PsiMethodCallExpression call) {
-      super.visitMethodCallExpression(call);
+    public void visitCallExpression(PsiCallExpression call) {
+      super.visitCallExpression(call);
       final PsiExpressionList argumentList = call.getArgumentList();
+      if (argumentList == null) {
+        return;
+      }
       final PsiExpression[] arguments = argumentList.getExpressions();
       if (arguments.length == 0) {
         return;

plugins/InspectionGadgets/test/com/siyeh/igtest/bugs/null_argument_to_variable_arg_method/NullArgumentToVariableArgMethod.java

@@ -25,4 +25,11 @@ class X {
     public static String join(CharSequence delimiter, CharSequence... elements) {
         return "";
     }
+}
+class AB {
+    AB(String msg, Object... args) {}
+
+    void m(String e) {
+        new AB("reactor", <warning descr="Confusing argument 'null', unclear if a varargs or non-varargs call is desired">null</warning>);
+    }
 }