Check delete permission on every page in a wiki subtree delete

wiki/src/org/labkey/wiki/WikiController.java

@@ -392,7 +392,8 @@ public ModelAndView getConfirmView(WikiNameForm form, BindException errors)
             if (!perms.allowDelete(_wiki))
                 throw new UnauthorizedException("You do not have permissions to delete this wiki page");
 
-            return new JspView<>("/org/labkey/wiki/view/wikiDelete.jsp", _wiki);
+            // GH Issue 1468: warn up front, rather than failing on submit, when the subtree can't be deleted
+            return new JspView<>("/org/labkey/wiki/view/wikiDelete.jsp", new WikiDeleteBean(_wiki, findUndeletableDescendant(perms, _wiki)));
         }
 
         @Override
@@ -407,10 +408,23 @@ public boolean handlePost(WikiNameForm form, BindException errors) throws Except
             if (!perms.allowDelete(_wiki))
                 throw new UnauthorizedException("You do not have permissions to delete this wiki page");
 
+            // GH Issue 1468: permission on the root page (e.g., as its creator) doesn't extend to descendants created by
+            // others. Check the whole subtree up front so the delete is all-or-nothing, then check each page again just
+            // before it's deleted to catch any child added concurrently.
+            if (form.getIsDeletingSubtree())
+            {
+                Wiki blocked = findUndeletableDescendant(perms, _wiki);
+                if (null != blocked)
+                    throw undeletableDescendantException(blocked);
+            }
+
             try
             {
                 //delete page and all versions
-                getWikiManager().deleteWiki(getUser(), c, _wiki, form.getIsDeletingSubtree());
+                getWikiManager().deleteWiki(getUser(), c, _wiki, form.getIsDeletingSubtree(), descendant -> {
+                    if (!perms.allowDelete(descendant))
+                        throw undeletableDescendantException(descendant);
+                });
             }
             catch (OptimisticConflictException e)
             {
@@ -419,6 +433,27 @@ public boolean handlePost(WikiNameForm form, BindException errors) throws Except
             return true;
         }
 
+        // Returns the first descendant (depth-first) the user cannot delete, or null if all are deletable.
+        // A single blocked page prevents the subtree delete, so there's no need to collect every blocked page.
+        private @Nullable Wiki findUndeletableDescendant(BaseWikiPermissions perms, Wiki wiki)
+        {
+            for (Wiki child : wiki.children())
+            {
+                if (!perms.allowDelete(child))
+                    return child;
+
+                Wiki blocked = findUndeletableDescendant(perms, child);
+                if (null != blocked)
+                    return blocked;
+            }
+            return null;
+        }
+
+        private UnauthorizedException undeletableDescendantException(Wiki descendant)
+        {
+            return new UnauthorizedException("You do not have permissions to delete the child wiki page '" + descendant.getName() + "', so this wiki subtree can't be deleted");
+        }
+
         @Override
         public void validateCommand(WikiNameForm wikiNameForm, Errors errors)
         {
@@ -443,6 +478,8 @@ public ActionURL getFailURL(WikiNameForm wikiNameForm, BindException errors)
         }
     }
 
+    public record WikiDeleteBean(Wiki wiki, @Nullable Wiki undeletableDescendant){}
+
     public enum NextAction
     {
         page(PageAction.class), manage(ManageAction.class), edit(EditWikiAction.class);

wiki/src/org/labkey/wiki/WikiManager.java

@@ -95,6 +95,7 @@
 import java.util.Objects;
 import java.util.concurrent.CopyOnWriteArrayList;
 import java.util.concurrent.atomic.AtomicInteger;
+import java.util.function.Consumer;
 
 import static org.labkey.api.action.SpringActionController.ERROR_MSG;
 import static org.labkey.api.security.WikiTermsOfUseProvider.TERMS_OF_USE_WIKI_NAME;
@@ -373,9 +374,19 @@ public void replaceAliases(Wiki wiki, Collection<String> newAliases, @Nullable B
     }
 
     public void deleteWiki(User user, Container c, Wiki wiki, boolean isDeletingSubtree) throws SQLException
+    {
+        deleteWiki(user, c, wiki, isDeletingSubtree, null);
+    }
+
+    /**
+     * @param descendantCheck when deleting a subtree, invoked on each descendant immediately before it's deleted; it
+     *                        should throw to prevent the deletion. Pages deleted before the throw stay deleted, but a
+     *                        page is never deleted before its descendants, so the remaining tree is never orphaned.
+     */
+    public void deleteWiki(User user, Container c, Wiki wiki, boolean isDeletingSubtree, @Nullable Consumer<Wiki> descendantCheck) throws SQLException
     {
         //shift children to new parent, or delete recursively if deleting the whole subtree
-        handleChildren(user, c, wiki, isDeletingSubtree);
+        handleChildren(user, c, wiki, isDeletingSubtree, descendantCheck);
 
         DbScope scope = comm.getSchema().getScope();
 
@@ -405,7 +416,7 @@ public void deleteWiki(User user, Container c, Wiki wiki, boolean isDeletingSubt
     }
 
 
-    private void handleChildren(User user, Container c, Wiki wiki, boolean isDeletingSubtree) throws SQLException
+    private void handleChildren(User user, Container c, Wiki wiki, boolean isDeletingSubtree, @Nullable Consumer<Wiki> descendantCheck) throws SQLException
     {
         //shift any children upward so they are not orphaned
 
@@ -417,7 +428,11 @@ private void handleChildren(User user, Container c, Wiki wiki, boolean isDeletin
             if(isDeletingSubtree)
             {
                 for(Wiki childWiki : children)
-                    deleteWiki(user, c, childWiki, true);
+                {
+                    if (null != descendantCheck)
+                        descendantCheck.accept(childWiki);
+                    deleteWiki(user, c, childWiki, true, descendantCheck);
+                }
             }
             else
             {

wiki/src/org/labkey/wiki/view/wikiDelete.jsp

@@ -18,15 +18,21 @@
 <%@ taglib prefix="labkey" uri="http://www.labkey.org/taglib" %>
 <%@ page import="org.labkey.api.view.HttpView" %>
 <%@ page import="org.labkey.api.view.JspView" %>
+<%@ page import="org.labkey.wiki.WikiController.WikiDeleteBean" %>
 <%@ page import="org.labkey.wiki.model.Wiki" %>
 <%@ page extends="org.labkey.api.jsp.JspBase" %>
 <%
-    JspView<Wiki> me = HttpView.currentView();
-    Wiki wiki = me.getModelBean();
+    JspView<WikiDeleteBean> me = HttpView.currentView();
+    WikiDeleteBean bean = me.getModelBean();
+    Wiki wiki = bean.wiki();
+    Wiki undeletableDescendant = bean.undeletableDescendant();
 %>
 
 Are you sure you want to delete this page?
 <p/>
 <b>name: <%=h(wiki.getName())%></b><br/>
 <b>title: <%=h(wiki.getLatestVersion().getTitle())%></b><br/>
-<br/><labkey:checkbox id="isDeletingSubtree" name="isDeletingSubtree" value="true" checked="false"/> Delete Entire Wiki Subtree
+<br/><labkey:checkbox id="isDeletingSubtree" name="isDeletingSubtree" value="true" checked="false" disabled="<%=null != undeletableDescendant%>"/> Delete Entire Wiki Subtree
+<% if (null != undeletableDescendant) { %>
+<br/><span class="labkey-error">You can't delete the entire subtree because you don't have permission to delete the child page '<%=h(undeletableDescendant.getName())%>'.</span>
+<% } %>