Created attachment 46227 [details]
Zero results don't appear when this workbook is opened.
When you save a workbook zero values are not saved if they are formula results.
This is not a big issue when "Tools / Cell Contents / AutoCalculate" is on since, when opening the workbook, formulas are recalculated and their results are shown.
However, if "AutoCalculate" is off, then recalculation doesn't happen and zero results are left blank (even if "Tools / Options / LibreOffice Calc / View / Zero values" is checked).
In attachment an example workbook. A zero appears on A1 because it's not a formula. Zeros should appear in cells A2, A3, A4 and A5 but they don't. Press F9 to force calculation and you will see all zero values.
1) I've first noticed this bug in OOo 3.3.0 and I reported it in OOo's issue tracker (106135). It has been confirmed there.
2) The same problem happens on Windows Vista x86-64.
Created attachment 46228 [details]
Patch to fix bug 36748.
Also sent to the dev mailing list:
Released under LGPLv3+ / MPL.
Pretty safe fix. I pushed it to the 3.4 branch. Thanks a lot.