an improvement could be in the specification of a multiplier area and a multiplicand area.
The multiplier area and the multiplicand area must have:
  the same size,
  either be in column or in line,
  or one could be in column and the other in line and vice versa.
Each cell in the multiplier area have to be multiplied by the corresponding cell in the multiplicand area.
Corresponding cells are: first cell of the multiplier area with the first cell of the multiplicand area, second one with the second one, etc

That wouldn't deliver a single return value though like SUMIF() (note it's not SUM.IF() that was probably because in French it's SOMME.SI()) but an array/matrix and that can already be accomplished by entering
=range1*range2*condition
as array formula, i.e. closing it with Shift+Ctrl+Enter instead of Enter.
Example: =A1:A5*B1:B5*(C1:C5<>23)
multiplies cells of A1:B5 with cells of B1:B5 if the corresponding value in C1:C5 does not equal 23; returns an array of 5 values, 0 if condition is not met.

If in comment 0 you meant to multiply all values of a range for a condition, that can be accomplished similar using
=PRODUCT(IF(C1:C5<>23;A1:A5;""))
as array formula (French PRODUIT()).

@ Eike Rathke
waouh, so great!
I don't have this description in my french documentation. Thanks a lot Eike

Considering the final response copied below, I believe this is resolved. Possibly an opportunity for French version documentation enhancement.

Also it does not appear to be a bug submission but an enhancement request.

@ Eike Rathke
waouh, so great!
I don't have this description in my french documentation. Thanks a lot Eike