#914 Fix changing subject in new form could cause parent change in e…

browser/CHANGELOG.md

@@ -20,6 +20,7 @@ This changelog covers all five packages, as they are (for now) updated as a whol
 - Moved the resource context menu to the top of the page.
 - [#861](https://github.com/atomicdata-dev/atomic-server/issues/861) Fix long usernames overflowing on the share page.
 - [#906](https://github.com/atomicdata-dev/atomic-server/issues/906) Reset changes after clicking the cancel button in a form or navigating away.
+- [#914](https://github.com/atomicdata-dev/atomic-server/issues/914) Fix an issue where changing the subject in a new resource form could update the parent of existing resources if their subject matched the new subject.
 
 ### @tomic/lib
 

browser/data-browser/src/components/forms/NewForm/useNewForm.ts

@@ -41,6 +41,11 @@ export const useNewForm = (args: UseNewForm) => {
   // When the resource is created or updated, make sure that the parent and class are present
   useEffect(() => {
     (async () => {
+      if (!resource.new) {
+        // The resource we are trying to create already exists, don't update any values.
+        return;
+      }
+
       if (parentVal !== parent) {
         await resource.set(core.properties.parent, parent);
       }

lib/src/commit.rs

@@ -128,6 +128,9 @@ impl Commit {
         if opts.validate_timestamp {
             check_timestamp(self.created_at)?;
         }
+
+        self.check_for_circular_parents()?;
+
         let commit_resource: Resource = self.into_resource(store)?;
         let mut is_new = false;
         // Create a new resource if it doens't exist yet
@@ -263,6 +266,20 @@ impl Commit {
         Ok(commit_response)
     }
 
+    fn check_for_circular_parents(&self) -> AtomicResult<()> {
+        // Check if the set hashset has a parent property and if it matches with this subject.
+        if let Some(set) = self.set.clone() {
+            if let Some(parent) = set.get(urls::PARENT) {
+                if parent.to_string() == self.subject {
+                    return Err("Circular parent reference".into());
+                }
+            }
+        }
+
+        // TODO: Check for circular parents by going up the parent tree.
+        Ok(())
+    }
+
     /// Updates the values in the Resource according to the `set`, `remove`, `push`, and `destroy` attributes in the Commit.
     /// Optionally also updates the index in the Store.
     /// The Old Resource is only needed when `update_index` is true, and is used for checking