sumif condition does not work with empty cells (regression)

Regression for Gnumeric 1.12.45 on Debian.

In sumif, the condition for an empty cell always returns false.

In the attached file the formulas in cells E3 and F3 should produce 1, but both produce 0 instead, which is wrong.

The same formulas produce the correct result when the file is read in Libreoffice 6.3.2 on Debian and in Gnumeric 1.10.17 on Ubuntu