IG: don't expect an array of generic type in "Suspicious 'Collection.toArray()' call" inspection

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

@@ -1,5 +1,5 @@
 /*
- * Copyright 2005-2013 Bas Leijdekkers
+ * Copyright 2005-2015 Bas Leijdekkers
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -20,6 +20,7 @@ import com.intellij.psi.util.InheritanceUtil;
 import com.siyeh.InspectionGadgetsBundle;
 import com.siyeh.ig.BaseInspection;
 import com.siyeh.ig.BaseInspectionVisitor;
+import com.siyeh.ig.psiutils.TypeUtils;
 import org.jetbrains.annotations.NonNls;
 import org.jetbrains.annotations.NotNull;
 
@@ -124,6 +125,22 @@ public class SuspiciousToArrayCallInspection extends BaseInspection {
         if (componentType.isAssignableFrom(parameter)) {
           return;
         }
+        if (parameter instanceof PsiClassType) {
+          final PsiClassType classType = (PsiClassType)parameter;
+          final PsiClass aClass = classType.resolve();
+          if (aClass instanceof PsiTypeParameter) {
+            final PsiTypeParameter typeParameter = (PsiTypeParameter)aClass;
+            final PsiReferenceList extendsList = typeParameter.getExtendsList();
+            final PsiClassType[] types = extendsList.getReferencedTypes();
+            if (types.length == 0) {
+              registerError(argument, TypeUtils.getObjectType(argument));
+            }
+            else if (types.length == 1) {
+              registerError(argument, types[0]);
+            }
+            return;
+          }
+        }
         registerError(argument, parameter);
       }
     }

plugins/InspectionGadgets/testsrc/com/siyeh/ig/bugs/SuspiciousToArrayCallInspectionTest.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2000-2013 JetBrains s.r.o.
+ * Copyright 2000-2015 JetBrains s.r.o.
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -35,6 +35,17 @@ public class SuspiciousToArrayCallInspectionTest extends LightInspectionTestCase
                  "}");
   }
 
+  public void testGenerics() {
+    doTest("import java.util.*;" +
+           "class K<T extends Integer> {\n" +
+           "    List<T> list = new ArrayList<>();\n" +
+           "\n" +
+           "    String[] m() {\n" +
+           "        return list.toArray(/*Array of type 'java.lang.Integer[]' expected*/new String[list.size()]/**/);\n" +
+           "    }\n" +
+           "}");
+  }
+
   @Override
   protected InspectionProfileEntry getInspection() {
     return new SuspiciousToArrayCallInspection();