datafile no longer 1.8 compatible with r13734

[Christian Stimming]

The latest 1.9.x releases *used* to write a data file that could still be read 
by 1.8.12. That was a very convenient way to get used to the new version but 
all the while keep the 1.8.12 version around and working. My data file in 
question is quite simple -- no business features, no stocks, but nevertheless 
2-3 different currencies and extensive HBCI features.

However, with one of the "commodity namespace" related changes in the last 
days, this is now no longer the case. When reading the file as written by 
r13734 in 1.8.12, gnucash barfs with the error message below, and contrary to 
beforehand gnucash-1.8.12 will not open any data. (gnucash shows an empty 
account hierarchy.)

Do we consider this a bug or a feature? As long as there is no stable 2.0.x 
branch I consider it a bug! I certainly expect that 2.0.x offers me the 
option to test it on my data file, but in case anything doesn't work as 
expected, it should easily be possible to go back from 2.0.x to 1.8.12 and 
continue the work as I did during the last years.

In other words, I'd ask to either refrain from writing stuff into the file 
that cannot be read by 1.8.12 (and *only* 1.8.12; we don't need compatibility 
to anything before that IMHO), *or* we need some function "export to 1.8.x 
gnucash data file" really quickly. IMHO even in 2.0.0 we *must* give a user 
the option to give 2.0.0 a try but if for whatever reason it doesn't work 
he/she should be able to go back into 1.8.12 with her data. 

This can be dropped once the first 2.0.x have proven stable enough, but this 
is still in the future.

Regards,

Christian


Error message when opening a r13734 datafile in gnucash-1.8.12:

Warning: valid_commodity: Invalid commodity: 0 fraction
Warning: gnc_commodity_end_handler: Invalid commodity parsed
<gnc:commodity version="2.0.0">
  <cmdty:space>ISO4217</cmdty:space>
  <cmdty:id>EUR</cmdty:id>
  <cmdty:get_quotes/>
  <cmdty:quote_source>currency</cmdty:quote_source>
  <cmdty:quote_tz/>
</gnc:commodity>