1.18.00.00 Crash in sample editor.

[Paul Legovitch]

Full Version:
OpenMPT v1.18.00.00

Has the bug occured in previous versions? If yes, please specify version(s):
1.17.03.03 is also crashing, but 1.17.03.02 works fine.

Description of the bug:
In the sample editor, ompt crashes after 2 or 3 operations from the sample toolbar (normalize, amplify, etc.) or from shortcuts (Ctrl+X, etc).

How often does it happen?:
Everytime I use the sample editor in 1.18.00.00 or 1.17.03.03 (never in 1.17.03.02)
I use linux+wine but I have the exact same behaviour in winXP.

How to reproduce (step by step description):
Ex : open a module with a few samples. Ctrl+X to cut a sample, go to another sample, click downsample, then normalize and the crash occurs.

[Saga Musix]

That's very strange. Does it also happen in the latest "stuff" build?

[Paul Legovitch]

Yes, the latest .01 has the same behaviour.
I'm going to take a wild guess and say this bug has to do with the sample undo feature introduced in 1.17.03.03 and 1.18.00.00.
I have a laptop with only 256 Mo Ram, so maybe it's related though the crashes occur with short samples and few changes (not memory demanding).

[Saga Musix]

Please add the section "[Sample Editor]" to your mptrack.ini and play around a bit with the "UndoBufferSize" value in this section. The value is in Megabytes, the default on your system should be 64mb, so you could try something like UndoBufferSize=1 or UndoBufferSize=10 to see if it helps.

[Paul Legovitch]

I had a hard time finding the mptrack.ini file : I thought I would find it with the .exe but it was in a hidden folder called Application Data.
Anyway I tested UndoBufferSize=1 and 10 and both seems to solve the problem, I couldn't make ompt crash while clicking on every sample editing tools like a mad man !
So it's great ! But what's the difference between 1 and 10 ?

[Saga Musix]

I had a hard time finding the mptrack.ini file : I thought I would find it with the .exe but it was in a hidden folder called Application Data.

The official release (as you might know, releases 1.17.03 through 1.18 were all just testing releases) will contain a link to the AppData directory in the tracker's directory, so the files will be easier to locate.

The difference between 1 and 10 is easy: UndoBufferSize=1 will restrict the undo buffer size to 1 MiB, 10 will restrict it to 10 MiB.

In the meanwhile, I have found (and fixed) a problem related to this (the maximum size was not set to 64 MiB in your case, but something close to 256 MiB), but I will dig into this some more to find out why OpenMPT actually crashes.

EDIT: Please try again with the latest "stuff" version. If it works alright without the UndoBufferSize variable being set, please try again with UndoBufferSize=512 and see if the problem occurs again.

[Paul Legovitch]

The latest version does not crash, either with or without UndoBufferSize=512 (as a comparison I tested the same operations on the same samples with 1.18.00.00, the crash occurs after 3-4 clicks).
So it works, plus I can undo multiple times (only one time with UndoBufferSize=1 but here I did not encounter any limit).

[Saga Musix]

Hmm, it's strange that it does not crash anymore at all as the "other" fix I applied was a fix in the undo code for deleting sample selections. But good to know that it doesn't crash anymore.

I guess you can close this bug report then.