SLING-12697 do not check for violations when the response is commited… (#58)

* SLING-12697 do not check for violations when the response is commited as the content type header change will be ignored according to the servlet api specification - avoid false positives
* SLING-12697 fix sonar issue

Author: RemoLiechti

src/main/java/org/apache/sling/engine/impl/SlingHttpServletResponseImpl.java

@@ -325,7 +325,7 @@ private String getCurrentStackTrace() {
 
     @Override
     public void setContentType(final String type) {
-        if (!isInclude()) {
+        if (super.getResponse().isCommitted() || !isInclude()) {
             super.setContentType(type);
         } else {
             Optional<String> message = checkContentTypeOverride(type);
@@ -358,7 +358,7 @@ public void setContentType(final String type) {
      * @param contentType the 'Content-Type' value that is being set
      * @return an optional message to log
      */
-    private Optional<String> checkContentTypeOverride(@Nullable String contentType) {
+    protected Optional<String> checkContentTypeOverride(@Nullable String contentType) {
         if (requestData.getSlingRequestProcessor().getContentTypeHeaderState() == ContentTypeHeaderState.VIOLATED) {
             // return immediatly as the content type header has already been violated
             // prevoiously, no more checks needed

src/test/java/org/apache/sling/engine/impl/SlingHttpServletResponseImplTest.java

@@ -87,6 +87,24 @@ public class SlingHttpServletResponseImplTest {
         "4749 LOG Adding bindings took 4 microseconds"
     };
 
+    @Test
+    public void testNoViolationChecksOnCommitedResponse() {
+        final SlingHttpServletResponse orig = Mockito.mock(SlingHttpServletResponse.class);
+        Mockito.when(orig.isCommitted()).thenReturn(true);
+
+        final RequestData requestData = mock(RequestData.class);
+        final DispatchingInfo info = new DispatchingInfo(DispatcherType.INCLUDE);
+        when(requestData.getDispatchingInfo()).thenReturn(info);
+        info.setProtectHeadersOnInclude(true);
+
+        final SlingHttpServletResponseImpl include = new SlingHttpServletResponseImpl(requestData, orig);
+        SlingHttpServletResponseImpl spyInclude = Mockito.spy(include);
+
+        spyInclude.setContentType("someOtherType");
+        Mockito.verify(orig, times(1)).setContentType(Mockito.any());
+        Mockito.verify(spyInclude, never()).checkContentTypeOverride(Mockito.any());
+    }
+
     @Test
     public void testReset() {
         final SlingHttpServletResponse orig = mock(SlingHttpServletResponse.class);