More than 99 undo steps?

[GoogleCodeExporter]

Just yesterday I overwrote the wrong file and made more than 99 clicks before I 
noticed it, so I couldn't get back and restore it

I assume as with all seemingly arbitrary limitations, that the concern is 
compatibility with older platforms.
Is it possible to have more than 99 undo steps on systems with enough memory?

Original issue reported on code.google.com by ilija.melentijevic on 31 May 2012 at 1:38

• Merged into: #174

[GoogleCodeExporter]

When using layers or animations, and a big resolution, the memory use for 
backups can get huge quite fast.

We have problems with knowing the amount of free memory, because :
 * Some OS return weird values when we ask for it,
 * On linux, malloc will never say when there is no space. Instead, it will kill a random program !

So, with more undo steps, we risk grafx2 or any other program getting killed, 
or other weirdness.

In settings > File selector, there is a "backup" option. This will create a BAK 
file when you overwrite something. Does that help ?

I was also thinking about it and I think what we could do is trigger a save 
after 99 steps (when the undo list is full and we start dropping pages from it).

There is also the very old issue about delta-packing the very old undo steps so 
they don't waste as much memory: #174 . Going to reopen it, then ;)

Original comment by pulkoma...@gmail.com on 10 Jun 2012 at 8:20

• Changed state: Duplicate
• Added labels: Milestone-NotPlanned, OpSys-All
• Removed labels: Milestone-, OpSys-

[GoogleCodeExporter]

I confirm that on Windows too, we can't auto-detect a safe memory limit.
In practice, memory problems (system slowdown due to swapping) will only happen 
when working on huge images (ex: entire game levels), so if we increase the 
limit above 100 I'd feel safer if the user could set a second limit in 
Megabytes, according to his own system: Users of desktop computers could safely 
set 500Mb for example, which is enough for 6400 steps on a 320x256 image. As a 
number of Undos it's more than enough, and at the same time, after several 
hours of drawing Grafx2 will have a constant limit of memory usage.

In the case that iLKke described, it's indeed the "Backup" option that would 
have given a safety against the accidental overwrite of wrong file.

Original comment by yrizoud on 10 Jun 2012 at 2:57