Calc : Should not allow to compute out of an error

reactos-bootcd-0.4.15-dev-6658-g88808ba-x86-gcc-lin-dbg

• Open Calc
• Type : -1
• Sqrt
• Shows "Error"
• Type : 3
• Shows "Error3,"
• hit "back"
• letters are removed one by one
• When "NaN" is displayed, it should not be possible to enter digit or operator (Win 2K3) OR it should show "0" (Win 11)
• "Back" should not remove letter. Ideally,it should have no effect (Win 2K3) OR it should show "0" (Win 11)

Guilty code is : https://git.reactos.org/?p=reactos.git;a=blob;f=base/applications/calc/winmain.c;hb=fa4b38d902d13072b7b982a4411a31cb84ab24b3#l1630 where content shall be erased if NaN before processing a "digit" input

Fix : calc_nan.patch