This was a complex change requiring three new functions:
file_merge_files_from_draft_area_into_filearea - To just add files from a draft area into a real one (just adding or updating, not deleting)
file_merge_draft_area_into_draft_area - To merge files from two draft areas, used by the latest for creating a draft area with all the original files plus the new ones.
file_overwrite_existing_draftfile - Required to update existing files not losing metadata or references.
The whole process is the following:
User uploads a file (upload.php)
Client gets a new draftid A containing the file only (return of upload.php)
Client requests to merge that draftid in the user's private files (core_user_add_user_private_files)
Server prepares a new UNUSED draftid B from existing area
Server merges A into B
Server saves the draft B into the final area
1. Implement core_course_get_contents web service
2. Implement callbacks in folder, resource, page and url modules
3. Implement download script for web service
Refactoring and improvements of the accesslib.php library including prevention of access for not-logged-in users when forcelogin enabled, improved context caching, OOP refactoring of contexts, fixed context loading, deduplication of role definitions in user sessions, installation improvements, decoupling of enrolment checking from capability loading, added detection of deleted and non-existent users in has_capability(), new function accesslib test, auth and enrol upgrade notes.
More details are available in tracker subtasks.
Andrew Nicols