Bug 15965 - Random.Next([maxValue == zero]) throws DivideByZeroException
Summary: Random.Next([maxValue == zero]) throws DivideByZeroException
Alias: None
Product: Class Libraries
Classification: Mono
Component: mscorlib ()
Version: 3.2.x
Hardware: PC Mac OS
: --- normal
Target Milestone: Untriaged
Assignee: Bugzilla
Depends on:
Reported: 2013-11-06 09:45 UTC by Gabriël van der Kruijk
Modified: 2014-01-22 21:26 UTC (History)
2 users (show)

Is this bug a regression?: ---
Last known good build:

Notice (2018-05-24): bugzilla.xamarin.com is now in read-only mode.

Please join us on Visual Studio Developer Community and in the Xamarin and Mono organizations on GitHub to continue tracking issues. Bugzilla will remain available for reference in read-only mode. We will continue to work on open Bugzilla bugs, copy them to the new locations as needed for follow-up, and add the new items under Related Links.

Our sincere thanks to everyone who has contributed on this bug tracker over the years. Thanks also for your understanding as we make these adjustments and improvements for the future.

Please create a new report on GitHub or Developer Community with your current version information, steps to reproduce, and relevant error messages or log files if you are hitting an issue that looks similar to this resolved bug and you do not yet see a matching new report.

Related Links:

Description Gabriël van der Kruijk 2013-11-06 09:45:36 UTC
When you call:

Random r = new Random();

You'll get an exception (division by zero), should return 0:

Return Value
Type: System.Int32
A 32-bit signed integer greater than or equal to zero, and less than maxValue; that is, the range of return values ordinarily includes zero but not maxValue. However, if maxValue equals zero, maxValue is returned.

Source: http://msdn.microsoft.com/en-us/library/zd1bc8e5%28v=vs.110%29.aspx

Btw: Is it still possible to look at the source of MonoTouch somewhere? Or is that now closed?
Comment 1 Sebastien Pouliot 2014-01-22 21:26:57 UTC
That should already be fixed [1] but maybe it was not released in the version of Mono[Touch] you're using. It's hard to say without knowing the exact version numbers (in doubt please provide them* and I'll double check).

* The easiest way to get exact version information is to use the "Xamarin Studio" menu, "About Xamarin Studio" item, "Show Details" button and copy/paste the version informations (you can use the "Copy Information" button).

> Btw: Is it still possible to look at the source of MonoTouch somewhere? 

MonoTouch source code was never open/public. However a large part of the BCL (including Random [2] from mscorlib.dll) comes from the Mono project - which is open source and publicly visible on github.

[1] https://github.com/mono/mono/commit/edbcf074ce6cb21301a1a43d72f5c5b44694ac84
[2] https://github.com/mono/mono/blob/master/mcs/class/corlib/System/Random.cs