XWIKI-22222: Add the concept of "request effective author"

* Make the request effective author optional (while keeping the event listener that sets it to the currently authenticated user by default)

(cherry picked from commit 6510f9da)

xwiki-platform-core/xwiki-platform-oldcore/src/main/java/com/xpn/xwiki/web/PreviewAction.java

@@ -140,7 +140,7 @@ public String render(XWikiContext context) throws XWikiException
         // Make sure the current user doesn't use the programming rights of the previous content author (by editing a
         // document saved with programming rights, changing it and then previewing it). Also make sure the code
         // requiring programming rights is executed in preview mode if the current user has programming rights.
-        editedDocument.getAuthors().setEffectiveMetadataAuthor(context.getRequest().getEffectiveAuthor());
+        context.getRequest().getEffectiveAuthor().ifPresent(editedDocument.getAuthors()::setEffectiveMetadataAuthor);
         if (editedDocument.isContentDirty()) {
             editedDocument.getAuthors().setContentAuthor(editedDocument.getAuthors().getEffectiveMetadataAuthor());
         }

xwiki-platform-core/xwiki-platform-oldcore/src/main/java/com/xpn/xwiki/web/SaveAction.java

@@ -241,7 +241,7 @@ public boolean save(XWikiContext context) throws XWikiException
 
         UserReference currentUserReference = this.currentUserResolver.resolve(CurrentUserReference.INSTANCE);
         tdoc.getAuthors().setOriginalMetadataAuthor(currentUserReference);
-        tdoc.getAuthors().setEffectiveMetadataAuthor(request.getEffectiveAuthor());
+        request.getEffectiveAuthor().ifPresent(tdoc.getAuthors()::setEffectiveMetadataAuthor);
 
         if (tdoc.isNew()) {
             tdoc.getAuthors().setCreator(currentUserReference);

xwiki-platform-core/xwiki-platform-oldcore/src/main/java/com/xpn/xwiki/web/WrappingXWikiRequest.java

@@ -27,6 +27,7 @@
 import java.util.Enumeration;
 import java.util.Locale;
 import java.util.Map;
+import java.util.Optional;
 
 import javax.servlet.AsyncContext;
 import javax.servlet.DispatcherType;
@@ -498,7 +499,7 @@ public Cookie getCookie(String cookieName)
     }
 
     @Override
-    public UserReference getEffectiveAuthor()
+    public Optional<UserReference> getEffectiveAuthor()
     {
         return this.request.getEffectiveAuthor();
     }

xwiki-platform-core/xwiki-platform-oldcore/src/main/java/com/xpn/xwiki/web/XWikiRequest.java

@@ -19,11 +19,12 @@
  */
 package com.xpn.xwiki.web;
 
+import java.util.Optional;
+
 import javax.servlet.http.Cookie;
 import javax.servlet.http.HttpServletRequest;
 
 import org.xwiki.stability.Unstable;
-import org.xwiki.user.GuestUserReference;
 import org.xwiki.user.UserReference;
 
 public interface XWikiRequest extends HttpServletRequest
@@ -36,16 +37,16 @@ public interface XWikiRequest extends HttpServletRequest
 
     /**
      * @return the user that holds the responsibility, in terms of access rights, for the submitted data and the changes
-     *         triggered by this request. By default the effective author is the user that gets authenticated with the
-     *         information provided by this request. If the request doesn't indicate an effective author and no user is
-     *         authenticated then the {@link GuestUserReference} is returned.
+     *         triggered by this request. If the request doesn't indicate an effective author then the user that gets
+     *         authenticated with the information provided by this request (or the guest user, if authentication
+     *         information is missing) should be considered the effective author.
      * @since 15.10.11
      * @since 16.4.1
      * @since 16.5.0RC1
      */
     @Unstable
-    default UserReference getEffectiveAuthor()
+    default Optional<UserReference> getEffectiveAuthor()
     {
-        return GuestUserReference.INSTANCE;
+        return Optional.empty();
     }
 }

xwiki-platform-core/xwiki-platform-oldcore/src/main/java/com/xpn/xwiki/web/XWikiServletRequest.java

@@ -19,6 +19,8 @@
  */
 package com.xpn.xwiki.web;
 
+import java.util.Optional;
+
 import javax.servlet.http.Cookie;
 import javax.servlet.http.HttpServletRequest;
 import javax.servlet.http.HttpServletRequestWrapper;
@@ -107,8 +109,8 @@ public String getRemoteHost()
     }
 
     @Override
-    public UserReference getEffectiveAuthor()
+    public Optional<UserReference> getEffectiveAuthor()
     {
-        return (UserReference) getAttribute(ATTRIBUTE_EFFECTIVE_AUTHOR);
+        return Optional.ofNullable((UserReference) getAttribute(ATTRIBUTE_EFFECTIVE_AUTHOR));
     }
 }

xwiki-platform-core/xwiki-platform-oldcore/src/main/java/com/xpn/xwiki/web/XWikiServletRequestStub.java

@@ -34,6 +34,7 @@
 import java.util.Locale;
 import java.util.Map;
 import java.util.Objects;
+import java.util.Optional;
 import java.util.TreeMap;
 import java.util.Vector;
 import java.util.stream.Collectors;
@@ -918,8 +919,8 @@ public void setDaemon(boolean daemon)
     }
 
     @Override
-    public UserReference getEffectiveAuthor()
+    public Optional<UserReference> getEffectiveAuthor()
     {
-        return (UserReference) getAttribute(XWikiServletRequest.ATTRIBUTE_EFFECTIVE_AUTHOR);
+        return Optional.ofNullable((UserReference) getAttribute(XWikiServletRequest.ATTRIBUTE_EFFECTIVE_AUTHOR));
     }
 }

xwiki-platform-core/xwiki-platform-oldcore/src/test/java/com/xpn/xwiki/web/SaveActionTest.java

@@ -33,6 +33,7 @@
 import java.util.Collections;
 import java.util.Date;
 import java.util.List;
+import java.util.Optional;
 
 import javax.inject.Named;
 
@@ -148,7 +149,7 @@ void setup()
         this.context.setWiki(this.xWiki);
 
         this.mockRequest = mock(XWikiRequest.class);
-        when(this.mockRequest.getEffectiveAuthor()).thenReturn(this.effectiveAuthor);
+        when(this.mockRequest.getEffectiveAuthor()).thenReturn(Optional.of(this.effectiveAuthor));
         this.context.setRequest(this.mockRequest);
 
         this.mockResponse = mock(XWikiResponse.class);

xwiki-platform-core/xwiki-platform-wysiwyg/xwiki-platform-wysiwyg-api/src/main/java/org/xwiki/wysiwyg/script/WysiwygEditorScriptService.java

@@ -397,7 +397,7 @@ private XWikiDocument createSecurityDocument()
         XWikiContext xwikiContext = this.xcontextProvider.get();
         // We clone the document in order to not impact the environment (the document cache for example).
         XWikiDocument clonedDocument = xwikiContext.getDoc().clone();
-        clonedDocument.getAuthors().setContentAuthor(xwikiContext.getRequest().getEffectiveAuthor());
+        xwikiContext.getRequest().getEffectiveAuthor().ifPresent(clonedDocument.getAuthors()::setContentAuthor);
         this.injectTemoraryAttachments(clonedDocument);
         return clonedDocument;
     }