[Misc] Protect against null content (fix TPC)

xwiki-platform-core/xwiki-platform-rendering/xwiki-platform-rendering-parser/src/test/java/org/xwiki/rendering/internal/parser/DefaultContentParserTest.java

@@ -22,6 +22,7 @@
 import static org.hamcrest.CoreMatchers.any;
 import static org.hamcrest.CoreMatchers.equalTo;
 import static org.hamcrest.CoreMatchers.nullValue;
+import static org.junit.Assert.assertEquals;
 import static org.junit.Assert.assertThat;
 import static org.mockito.hamcrest.MockitoHamcrest.argThat;
 import static org.mockito.Mockito.when;
@@ -100,4 +101,11 @@ public void parseWhenNoParser() throws Exception
         thrown.expectCause(any(ComponentLookupException.class));
         mocker.getComponentUnderTest().parse("", Syntax.XWIKI_2_1, DOCUMENT_REFERENCE);
     }
+
+    @Test
+    public void parseWhenNullSource() throws Exception
+    {
+        XDOM xdom = mocker.getComponentUnderTest().parse(null, Syntax.PLAIN_1_0);
+        assertEquals(0, xdom.getChildren().size());
+    }
 }