XLSX-export: trailing zeros make trouble with Excel

[TobWen]

(as discussed on IRC)

When writing XLSX using ogr2ogr, double get casted to float. These floats might create problems when loading the file in Microsoft Excel.

Here is a working patch to fix this problem. Thanks to the guys in #c++ on freenode.

[Even Rouault]

%.16g instead of %.16f should be equivalent to your patch. But did you check that Excel will be happy with the scientific notation that will be output for small or big numbers, like 1.23456e-20

[TobWen]

Yeah, I wrote about %.16g in the channel yesterday. But it might work up to 10^{16 only. I'll try and report soon. My patch works for 100%, tested on some hundred thousand lines :)}

[Even Rouault]

In 41414:

XLSX: on writing, use %.16g formatting for floating point numbers (fixes #7230, patch by TobWen)

[Even Rouault]

In 41415:

XLSX: on writing, use %.16g formatting for floating point numbers (fixes #7230, patch by TobWen)