Designed Incompatibility

In certain circles, Microsoft is usually blamed for "extend, embrace, extinguish" where the "embrace" stands for purposefully changing a specification to create incompatibilities. This post is not addressing Microsoft but another group that is usually more standards compliant: the Apache Foundation.

In the release notes of the new Apache OpenOffice release, changes to the TIME function are advertised:

Spreadsheet: TIME function returns values 00:00:00 <= x <= 23:59:59.999
The TIME spreadsheet function returns values between 00:00:00 and 23:59:59.999... inclusive and wraps values equal to or greater than 24:00:00.

It is easy to verify that Apache OpenOffice saves this function as the ODF OpenFormula function TIME:

<table:table-cell table:formula="of:=TIME(48;0;0)" office:value-type="time" office:time-value="PT00H00M00S"><text:p>00:00:00</text:p></table:table-cell>

This means that normally this function should be compatible with the ODF 1.2 part 2 specification as outlined in 6.10.17, where it says:

Syntax: TIME( Number hours ; Number minutes ; Number seconds )
Semantics: Returns the fraction of the day consumed by the given time, i.e.: ((hours*60*60)+(minutes*60)+seconds)/(24*60*60)
Hours, minutes, and seconds may be any number (they shall not be limited to the ranges 0..24,0..59, or 0..60 respectively).

So ODF requires TIME(48;0;0) to evaluate to 2, while in the new Apache OpenOffice it evaluates to 0.

Note that this is the value calculated, depending on the cell format this value could look differently.  Both LibreOffice and Gnumeric evaluate TIME(48;0;0) as 2, but LibreOffice shows it as 48:0:0 while Gnumeric shows it as 00:00.


The Illusion of ODF Interoperability

We recently saw the first release of Apache OpenOffice, one of the branches of the fork. Since the tangled mess usually known as the Open Document Format (ODF) was initially based on the file format, one could reasonably expect that Apache OpenOffice and LibreOffice are both quite successful in implementing that file format. Especially since Apache OpenOffice was according to the initial Apache incubator proposal intended to

serve as a reference implementation of the Open Document Format standard

one should have expected an attempt to provide a correct ODF 1.2 implementation.

In 2009, a bug was filed against That bug report was later moved to Apache OpenOffice and duplicated to LibreOffice. Essentially this bug is related to how errors return by OpenFormula formulas are saved inside the ODF file. It should have been relatively easy to fix this bug. Unfortunately the recent Apache OpenOffice release shill exhibits the faulty behaviour. As a consequence other implementations that endeavour to provide interoperability still have to work around this bug.

It has abundantly clear to me that both Apache OpenOffice and LibreOffice at most provide lip service with regard to interoperability.