GUID fallback for custom field value lookup

src/changes/changes.xml

@@ -8,6 +8,7 @@
 		<release date="unreleased" version="13.5.2">
 			<action dev="joniles" type="update">Added the `Task.getBaselineTask()` methods. For applications where a separate baseline schedule is present or a baseline has been manually added to the `ProjectFile` instance, these methods will allow you to access the underlying baseline task instance from the current task instance.</action>
 			<action dev="joniles" type="update">Added the Activity Percent Complete attribute to the `Task` class. The value of this attribute will be the Duration, Physical or Units percent complete value, based on the Percent Complete Type setting. This attribute is provided as a convenience to match the Activity Percent Complete type value shown in P6.</action>
+			<action dev="joniles" type="update">Improve retrieval of custom field values for certain MPP files.</action>
 		</release>
 		<release date="2024-10-28" version="13.5.1">
 			<action dev="joniles" type="update">Fix CVE-2024-49771: Potential Path Traversal Vulnerability</action>

src/main/java/net/sf/mpxj/mpp/VarDataFieldReader.java

@@ -96,6 +96,11 @@ private Object getValueByID(byte[] data)
       else
       {
          item = m_customFields.getCustomFieldValueItemByUniqueID(uniqueId);
+         if (item == null)
+         {
+            // If the unique ID doesn't give us a result, fall back on the guid
+            item = m_customFields.getCustomFieldValueItemByGuid(guid);
+         }
       }
 
       return item == null ? guid : coerceValue(item.getValue());