Only emit annotation changes if it's a hash change

unison-share-api/src/Unison/Server/Backend/DefinitionDiff.hs

@@ -59,5 +59,17 @@ diffSyntaxText (AnnotatedText fromST) (AnnotatedText toST) =
     detectSpecialCase fromSegment toSegment
       | fromSegment == toSegment = Left fromSegment
       | AT.annotation fromSegment == AT.annotation toSegment = Right (SegmentChange (AT.segment fromSegment, AT.segment toSegment) (AT.annotation fromSegment))
-      | AT.segment fromSegment == AT.segment toSegment = Right (AnnotationChange (AT.segment fromSegment) (AT.annotation fromSegment, AT.annotation toSegment))
+      -- We only emit an annotation change if it's a change in just the hash of the element (optionally the KIND of hash reference can change too).
+      | AT.segment fromSegment == AT.segment toSegment,
+        Just _fromHash <- AT.annotation fromSegment >>= elementHash,
+        Just _toHash <- AT.annotation toSegment >>= elementHash =
+          Right (AnnotationChange (AT.segment fromSegment) (AT.annotation fromSegment, AT.annotation toSegment))
       | otherwise = error "diffSyntaxText: found Syntax Elements in 'both' which have nothing in common."
+      where
+        elementHash :: Syntax.Element -> Maybe Syntax.UnisonHash
+        elementHash = \case
+          Syntax.TypeReference hash -> Just hash
+          Syntax.TermReference hash -> Just hash
+          Syntax.DataConstructorReference hash -> Just hash
+          Syntax.AbilityConstructorReference hash -> Just hash
+          _ -> Nothing