Default [Q][test] change your rom without flashing anything [DUALBOOT ONLY]

Hi,

when i download some roms, release after release, i saw that, sometimes, only some files are changed.

if i make a little zip with only the differencies comparing two zip, and if i change updater-script
(deleting "delete system" process , deleting flashing kernel lines, generaly, at end of script and managing other things)
can someone confirm that if my updater-script never delete /system/ , i have no risk to "kill" my device ?

i have an idea about the reply but its good to have a thread about this question, no ?



i have test this following when i run a 2nd rom with dorimanx kernel.

- I search about differencies on two spirit releases rom. (using 7zip , good interface to compare and you have the total size of each folder in zip)
- On a structured folder, i keep only the new files from new release.
(apk, binary,priv-app,framework..., comparing them using size files essentialy because using the date as comparison filter never help in this way)
- i run my 2nd rom

1 - Remember us, with dorimanx kernel, when we are dualbooting roms, no matter the position rom you are run at a moment (1rst or 2nd), you will be able to see /system/ and /data/ partitions from the other rom which generaly sleep
2 - On PC, i generaly use WINSCP soft to acces easily on all structured folders of my device. (just let you know)


So,

- i launch WINSCP on PC, then i can log-in as root on my device, 2nd rom runing.
- in the interface gui of WINSCP, on left side, i see my extracted differencies structured with all files and in right side, i can see all folders from my device.
- with the interface gui from WINSCP, i can copy all that i need in /system_pri_rom/ and /data_pri_rom/ , which are the auto-mounted partitons from 1rst rom
- if DEV have moving some apks from /system/app/ to /system/priv-app/ , i move the files too. If DEV have delete some files, i delete too.
- when i reboot my 1rst rom, it booted without any trouble.

result :

the +
i dont flash anything
i dont change kernel

the -
looking for differencies between 2 zip take time

the +/-
i dont format/delete entire system and maybe with time, this can be corrupted.

If someone can help me this way by making a little script which can make the differencies with an output zip , it will be much appreciated

thanks.
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