Re: finally caught an error on crash

[Jack <ostroffjh users sourceforge net>]

On 2019.02.05 19:48, Jack wrote:
> Hello all,
>
> Very randomly, after downloading (POP3) and reading some messages, if  
> I click the button to expunge deleted messages (and this has only  
> happened in the Inbox, but I have no idea if that matters) Balsa will  
> just disappear.  I finally managed to get a launch icon capturing  
> stderr, and got
>
> ERROR:../balsa-git/libbalsa/mailbox_mbox.c:280:message_info_from_msgno:  
> assertion failed: (msgno > 0 && msgno <= mbox->msgno_2_msg_info->len)
>
> I haven't fully delved into the code, but I do assume the len is the  
> length of the array msgno_2_msg_info (not the length of some string,  
> as I first mis-assumed) which seems to be the number of messages in  
> the mailbox, so could something be happening out of order during the  
> expunge?  This is an mbox mailbox.
>
> I don't really see any G_MESSAGES_DEBUG values which would be  
> particularly useful.  I suppose I could run under gdb and set a  
> breakpoint on that function - but this happens rarely enough that I'm  
> not sure it would be worth the effort.  I suppose running under gdb  
> with no breakpoints would at least let me do a backtrace if I do  
> catch the crash again.
>
> Any thoughts or suggestions?
This continues to happen at a low, but still annoying frequency.  The  
line number in the error is now 247, having been 249 for a while,  
presumably just due to other edits to that file.  As I can remember, it  
happens after either deleting message(s) from the inbox, and/or moving  
message(s) to different mailboxes, in case that points to any  
possibilities.

Given the recent changes (in the cleanup-logging branch) I'm wondering  
if I might just for my own use add some additional debug statements,  
either in the function where the g-assert fails, or else before the  
calls to that function.  Any quick pointers (or even just a pointer to  
an example line or two) would be helpful, and also advice on which  
debug domain to use (or even to set for current testing) or how  to go  
about adding a new domain.

Thanks.

Jack