Ticket #47750 - Creating a glue fails if one above level is a conflict or missing
    
    Description: Poring changes made to 1.2.11 branch to newer versions.
    1) Enabiling cache lock in cache_is_in_cache and cache_has_otherref.
    2) Removing unused field new_entry_in_cache from "struct _modify_context".
    
    (cherry picked from commit 5ae13072330e9a769a5949b2e8a91085b38ac4e1)