makehistory can generate duplicate lines

[Julien ÉLIE]

Hi Kamil,

>> But I am almost sure that this is still something wrong with
>> makehistory/cnfs code.
>> It is not understandable for me that first article during scanning spool
>> has different cycle number than others. (On fully wrapped buffer)

Ah yes, there also was that 3rd bug!
1st - duplicate entry returned by makehistory on fully wrapped cycbuff
2nd - untimely expiry of the first article of a fully wrapped cycbuff
3rd - off-by-one cycle number of the first article of a fully wrapped 
cycbuff returned by makehistory


> --8<---------------cut here---------------start------------->8---
>      token = CNFSMakeToken(cycbuff->name, offset, cycbuff->blksz,
>                            (offset > cycbuff->free) ? cycbuff->cyclenum - 1
>                                                     : cycbuff->cyclenum,
>                            cah.class);
> --8<---------------cut here---------------end--------------->8---

Indeed, in cnfs_next() called by makehistory, the first article has 
offset == cycbuff->free, with cycle number already set to the next one. 
So I believe this patch fixes that 3rd bug.  I'll test it soon to make sure.

-- 
Julien ÉLIE

« Quand j'étais petit, je séchais la natation. » (Philippe Geluck)