Mark,

Recent upgrade instructions (1.1.1 -> 1.1.2) direct user to upgrade on file level as opposed to directory-level.
Upgrading the "minimal file set" is best solution when people 'mod' original release files, but a little cumbersome.
I've seen several bug reports that were the result of sloppiness (someone forgot to copy one file).

A more granular update check of vanilla-core could prevent many of these and make the process easier for less
technically inclined people (which would benefit the growth potential of Vanilla)

How difficult is this approach?

Pre-requisite: all official vanilla core release files contain a calculated CRC in the header (HCRC)

#1 - COLLECT
collect installed files list and CRC in header from user's server
retrieve list of file/CRC combos for latest release from Lussumo server

#2 - COMPARE
process list of installed files
a. if filename NOT in core release -> flag as 'custom' & skip (listing optional)
b. if in core release -> calculate CRC of installed file (CCRC)
compare CCRC with HCRC of installed file
if NOT the same -> file was modded -> flag 'user-modified', update optional (check box NOT set)
if the same -> this is an original file
COMPARE CCRC with HCRC of latest release version matching filename
if the same -> no update available, don't list
if different -> flag 'updated' and add update (check box IS set)

#3 - SELECT
- user reviews files to be included in download package using check boxes,
selection of updates to MODDED files allowed

#4a - DOWNLOAD
- user clicks 'update' and custom package is generated and sent as download

#4b - FUTURE: INSTALL
- put board in 'maintenance mode'
- back up files in download package to 'fall-back' install
- auto-update files
- in case of failure, user can revert to 'fall-back' install

I like it! How hard would it be to write this script (PHP or bash)?

Kinda sounds like SVN to me...

I do like the idea though :)

"Maybe next time around"

there's been 2 updates since then?? or does next time around now mean version 5.0

jk, this is only usually an issue for people who have edited core files ... in which case they're probably ok to do all of that on their own