[grisbi-bugs] [Grisbi 0001961]: rounds JPY to EUR exchange fees value incorrectly when saving gsb file to disk

[Grisbi Bug Tracker]

The following issue has been ASSIGNED. 
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http://www.grisbi.org/bugsreports/view.php?id=1961 
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Reported By:                LudovicRousseau
Assigned To:                pbiava
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Project:                    Grisbi
Issue ID:                   1961
Category:                   Main
Reproducibility:            have not tried
Severity:                   minor
Priority:                   normal
Status:                     assigned
OS:                         Debian 
Unstable Impact:            Yes 
Version OS:                 Stretch 
Version GTK:                 
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Date Submitted:             2019-08-06 17:59 CEST
Last Modified:              2019-08-14 09:22 CEST
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Summary:                    rounds JPY to EUR exchange fees value incorrectly
when saving gsb file to disk
Description: 
Dear Maintainer,

I'm using grisbi for a long time now. Recently I registered a few 
currency exchange debit transactions. From JPY to EUR and each time I 
save+close my gsb file, and then reopen it, I get rounded exchange fee 
(EXF) in my transactions. This behaviour completely messes up my accounting.

In order to be better understood, I attached to the present mail one 
file named exf_bug.gsb.

This file contains 4 transactions:

1. [OK] One Initial credit transaction of +100 EUR
2. [OK] One EUR debit transaction of : -15 EUR
3. [KO] One JPY debit transaction of : -1000 JPY (-13,33EUR + 1.67EUR
   (EXF))
4. [OK] One last EUR debit transaction of : -10 EUR

Before I close my gsb file, everything is OK in grisbi HMI.
I.e. There remains 60,00 EUR on the bank account (expected result).

If I save+close my gsb file and reopen it, grisbi shows 59,67 EUR as 
remaining on the bank account (KO).
If I give a look at the echange (rate) dialog box of the transaction n°3 
(upon 4), the exchange fees have been rounded from 1.67 EUR to 2.0 EUR. 
And in fact, the gsb file content shows an exf="2.0" for that transaction.

Moreover, I registered older currency exchange transactions in the past 
(e.g. of kind DKK to EUR).
Those DKK to EUR transactions works OK. Exchange fees are not rounded 
unexpectedly.
But the one we are talking about are the first one of kind JPY to EUR 
I'm registering.

The only difference between those three currencies is :

 * EUR : 2 digits max. after floating point
 * DKK : 2 digits max. after floating point
 * JPY : *0* digits after floating point

Following that analysis, it appears that when floating point formats of 
both currency source and destination are equal, grisbi behaves great 
(OK). E.g. DKK to EUR.
Nevertheless, it appears that when floating point formats of both 
currency source and destination are different, grisbi behaves oddly 
(KO). E.g. JPY to EUR.

So, I'm wondering if grisbi is not rounding exchange fees value based on 
the currency floating point format of the source (instead of the 
floating point format of the destination -- that applies in my case (as 
my exchange fees are expressed in EUR and as grisbi exchange (rate) 
window also seems to express them).

As I said, I would have expected that grisbi would have rounded exchange 
fees value based on the currency floating point format of the destination.
Or, in order to be more cautious, I would expect grisbi to round 
exhcange fees value repecting the biggest of the two max. digits after 
floating point values. E.g. when exchanging JPY(0) to EUR(2) or EUR(2) 
to JPY(0), always round to the biggest (0<2) : 2 digits max. after 
floating point.
As I don't know all grisbi usage, I would suggest the last solution not 
to break the initial behaviour.

Thanks a lot in advance for your support.

Best regards,

Additional Information: 
This is Debian bug #933872
https://bugs.debian.org/cgi-bin/bugreport.cgi?bug=933872
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Issue History 
Date Modified    Username       Field                    Change               
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2019-08-06 17:59 LudovicRousseauNew Issue                                    
2019-08-06 17:59 LudovicRousseauFile Added: exf_bug-obfuscated.gsb              
     
2019-08-14 09:22 pbiava         Assigned To               => pbiava          
2019-08-14 09:22 pbiava         Status                   new => assigned     
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