When I create a tristate check box control with the default state "Not defined" (which should correspond to NULL), the chosen default state is not reflected in a newly opened form. Instead of a default NULL state the checkbox is by default in the 0 state, when one starts a new record. This makes it impossible to make a form enter NULL by default for a boolean field.
@impocta : - which version of LibreOffice ? - are you using a distrib-provided version or the TDF version (download from LibreOffice website) ? Setting to NEEDINFO, please set back to UNCONFIRMED once you have provided these details.
See also bug 56612 and bug 45606 - I think this current report is a DUPLICATE of one of those two bugs.
Per comment 1 on bug 56612, please provide the database definition of the boolean field to which you are assigning a tristate checkbox. In fact, it would be better to provide us with a sample database that illustrates the problem.
The more I read bug 56612, the more it appears that this current report is a DUP of that bug - setting as such. *** This bug has been marked as a duplicate of bug 56612 ***
Confirmed reproduced in Version: 5.2.3.3 Build ID: d54a8868f08a7b39642414cf2c8ef2f228f780cf Threads CPU : 2; Version de l'OS :Mac OS X 10.12.1; UI Render : par défaut; Locale : fr-FR (fr_FR.UTF-8); Calc: group