Re: [Rosegarden-devel] Where is synthpluginmanager.rc

[Dave P. <dp...@we...>]

On 04/28/2010 11:18 AM, Chris Cannam wrote:
> Turns out to be fairly simple, and a very typical bug for us -- poor
> management of pointers-into-things when those things are switched
> about.
>
> When setting the synth instrument in the first document, the
> instrument parameter panel (the thing at the bottom-left of the main
> window) was told to display that synth instrument.  Then a new
> document was loaded, as a consequence of which that instrument was
> deleted, and a plugin assignment was made from the synth plugin
> manager.  That invoked a slot on the instrument parameter panel which
> attempted to do something with the (now deleted) instrument.
>
> The underlying cause was that the instrument pointer in the parameter
> panel was not being reset when the document was changed.  Fixed in rev
> 11881.
>
> Incidentally, the reason you had to go through the synth plugin
> manager to make this crash happen was that that way you can set a
> plugin without selecting a particular instrument in the parameter
> panel first, so that the invalid pointer is still sitting around in
> the panel.  Once you know the mechanics of it, you can actually crash
> it in various different ways, for example:
>
> 1. Start RG
> 2. Assign the first track to an audio instrument
> 3. File -> New
> 4. Open the audio mixer window
> 5. Click one of the plugin buttons for the first audio instrument
> 6. kersplat
>
> (Also fixed in that revision.)
>
> This is quite a significant bug, then, which could have bitten quite a
> few users.
>
>
> Chris
>
>   
There was two bugs open from Michel Munnix caused by this, glad it's
fixed at last. There's another one about a segfault in notation editor
when splitting a note in the main window with notation editor open. It's
a nasty difficult to reproduce one, Here's how it happens pasted direct
from the bug :-
I can reproduce if I reopen the file and do the following:
ctrl-A (select all)
N open notation editor
set font size to 14 (perhaps not important)
go to measure 26, select last note from track 2 (the upper one)
get main window in front, click on split track tool
click on track 2 separation between measures 26 and 27
-> got the segfault

I've attached his backtrace and the file he was working on. I haven't
managed to reproduce it myself but he's reproduced with 10.02 release,
10.04 release and the last 10.06 svn 11879.
There's two other bugs and an enhancement request still open, if you
have the time you can browse them at :-
https://bugzilla.novell.com/buglist.cgi?bug_status=ASSIGNED&bug_status=REOPENED&assigned_to=dav...@gm...
Thanks
Dave P