Calc functions and Calc option 'convert text to number'

[winfried.libreoffice@xxxxxxxxx (Winfried Donkers)]

Hi Eike,

I'm working on tdf64132, which is about SUM and text values that are not 
converted to numbers.

SUM uses ScInterpreter::IterateParameters(), which is used by various 
other Calc functions as well.

ScInterpreter::IterateParameters() does not handle the configuration 
settings for converting text to numbers properly.

For stack type svString I have a patch ready (gerrit #57346). The unit 
test is a problem for me, as the 'convert text to numbers' configuration 
is not in the test document and therefore unknown. This is illustrated 
by a test passing on my computer and failing for Jenkins.

But the larger challenge lies with stack type svDoubleRef (probably the 
most used one). Here a sc::ColumnSpanSet is used with 
sc::ColumnSpanSet::ColumnAction (a.o. FuncSum), which in turn uses 
NumericCellAccumulator. And that class handles only 
sc::element_type_numeric and sc::element_type_formula, so text is 
discarded. I could add sc::element_type_string and the conversion to 
numbers depending on the configuration settings.

As that will have consequences beyond the Calc functions SUM and the 
like, I would like you opinion on this before I start implementing.

And all this leads to the question if all Calc functions expecting 
numeric arguments handle the 'convert text to numbers' configuration as 
advertised. It looks like I can keep myself occupied for quite some time 
with this ;-)

Winfried