test of a fix

runtime/interpreter/decode.go

@@ -1118,6 +1118,29 @@ func (d *Decoder) decodeLocationAndTypeID(
 	}
 	typeID := sema.TypeID(encodedTypeID)
 
+	// Special case: The decoded location is an address location without name.
+	//
+	// In the first version of the storage format, accounts could only store one contract
+	// instead of several contracts (separated by name), so composite's locations were
+	// address locations without a name, i.e. just the bare address.
+	//
+	// An update added support for multiple contracts per account, which added names to address locations:
+	// Each contract of an account is stored in a distinct location.
+	//
+	// So to keep backwards-compatibility:
+	// If the location is an address location without a name,
+	// then infer the name from the type ID.
+
+	if addressLocation, ok := location.(ast.AddressLocation); ok && addressLocation.Name == "" {
+		qualifiedIdentifier := location.QualifiedIdentifier(typeID)
+		parts := strings.SplitN(qualifiedIdentifier, ".", 2)
+
+		location = ast.AddressLocation{
+			Address: addressLocation.Address,
+			Name:    parts[0],
+		}
+	}
+
 	return location, typeID, nil
 }