From: nobu@... Date: 2016-12-21T01:32:45+00:00 Subject: [ruby-core:78745] [Ruby trunk Bug#12548][Open] Rounding modes inconsistency between round versus sprintf Issue #12548 has been updated by Nobuyoshi Nakada. Description updated Status changed from Closed to Open Probably, [Feature #10000] can add `half` option to `String#%`. ---------------------------------------- Bug #12548: Rounding modes inconsistency between round versus sprintf https://bugs.ruby-lang.org/issues/12548#change-62119 * Author: Kieran McCusker * Status: Open * Priority: Normal * Assignee: * Target version: * ruby -v: 2.4.0 * Backport: 2.1: UNKNOWN, 2.2: UNKNOWN, 2.3: UNKNOWN ---------------------------------------- Hi I've found this possible bug with `sprintf` in our production code, but it seems very odd that no one has reported it so I'm doubting myself. I've tested a few versions (CRuby 2.3.1 and 2.1.9) and it was present in both. To reproduce in irb: ```ruby sprintf('%1.0f', 12.5) ``` Expected result 13 actual 12 In fact if you look at the number sequence 0.5 -> 99.5 you find the even half will all round down and the odd half round up. 12.5.round produces the correct result (13) If you do the same in jruby 2.2.1 you get the expected result of 13. Many thanks Kieran ---Files-------------------------------- round_even.patch (4.43 KB) -- https://bugs.ruby-lang.org/ Unsubscribe: