Round this
September 28th, 2007 by WesI can usually look at a bug and see at least one way the code could be borked. But this one just boggles me.
Yesterday evening we were alerted to an issue in Excel 2007 (and Excel Services 2007) involving calculation of numbers around 65,535. The first example that we heard about was =77.1*850, but it became clear from our testing as well as additional reports that this was just one instance where Excel 2007 would return a value of 100,000 instead of 65,535. The majority of these additional reports were focused on multiplication (ex. =5.1*12850; =10.2*6425; =20.4*3212.5 ), but our testing showed that this really didn’t have anything do to with multiplication - it manifested itself with many but not all calculations in Excel that should have resulted in 65,535 (=65535*1 and =16383.75*4 worked for instance). Further testing showed a similar phenomenon with 65,536 as well. This issue only exists in Excel 2007, not previous versions.
See also: Explaining the Excel Bug from Joel on Software
And let’s face it — do you really want the bright sparks who work there now, and manage to break lots of perfectly good working code — rewriting the core calculating engine in Excel? Better keep them busy adding and removing dancing paper clips all day long.