[NO ISSUE] Fix reading of external function identifiers from metadata

Change-Id: I266ee48079d93f783baed3245a42902b23ceb38c
Reviewed-on: https://asterix-gerrit.ics.uci.edu/c/asterixdb/+/8947
Integration-Tests: Jenkins <jenkins@fulliautomatix.ics.uci.edu>
Reviewed-by: Dmitry Lychagin <dmitry.lychagin@couchbase.com>
Contrib: Ian Maxon <imaxon@uci.edu>
Tested-by: Jenkins <jenkins@fulliautomatix.ics.uci.edu>
diff --git a/asterixdb/asterix-metadata/src/main/java/org/apache/asterix/metadata/entitytupletranslators/FunctionTupleTranslator.java b/asterixdb/asterix-metadata/src/main/java/org/apache/asterix/metadata/entitytupletranslators/FunctionTupleTranslator.java
index 0672906..81c654b2 100644
--- a/asterixdb/asterix-metadata/src/main/java/org/apache/asterix/metadata/entitytupletranslators/FunctionTupleTranslator.java
+++ b/asterixdb/asterix-metadata/src/main/java/org/apache/asterix/metadata/entitytupletranslators/FunctionTupleTranslator.java
@@ -151,7 +151,7 @@
             externalIdentifier = new ArrayList<>(externalIdentifierList.size());
             IACursor externalIdentifierCursor = externalIdentifierList.getCursor();
             while (externalIdentifierCursor.next()) {
-                externalIdentifierList.add(externalIdentifierCursor.get());
+                externalIdentifier.add(((AString) externalIdentifierCursor.get()).getStringValue());
             }
             libraryName = getString(functionRecord, MetadataRecordTypes.FIELD_NAME_LIBRARY_NAME);
             String libraryDataverseCanonicalName = getString(functionRecord, FIELD_NAME_LIBRARY_DATAVERSE_NAME);