[MATH-1241] Digamma calculation produces SOE on NaN argument

• Type: Bug
• Status: Closed
• Priority: Minor
• Resolution: Fixed
• Affects Version/s: 3.5
• Fix Version/s: 4.0, 3.6
• Assignee: Unassigned
• Reporter: Aleksei Dievskii
• Created: 24/Jun/15 12:49
• Updated: 25/Jan/16 20:27
• Resolved: 24/Jun/15 13:43

Description

Digamma doesn't work particularly well with NaNs.

How to reproduce: call Gamma.digamma(Double.NaN)

Expected outcome: returns NaN or throws a meaningful exception

Real outcome: crashes with StackOverflowException, as digamma enters infinite recursion.