Created attachment 4884 patch to mainbox.c to hide empty tooltip "Location:" and "Notes:" lines. The tooltip on todos which do not have a location or notes currently show "Location: (null)" and "Notes: (null)", which is distracting, and also likely confusing to non-programmers. The following patch simply does not print the "Location:" or "Notes:" lines, if they are NULL. Note: This patch changes some translated strings.
Will implement soon. Thanks for the patch. (I will first release a small version with only non translation changes.)
This is now in git in 4.9.1.0 version. Thanks again for the patch1 (I had to change it a little as there were som eother changes to this code area.)
Fixed in 4.10.0