From: mame@... Date: 2019-05-09T07:35:06+00:00 Subject: [ruby-core:92610] [Ruby trunk Bug#15816] String#casecmp compares uppercase characters instead of lowercase Issue #15816 has been updated by mame (Yusuke Endoh). Until ruby 1.8.7, it seemed to use downcase. It was changed at r14227 to support encoding. I think the behavior change was not intended, so this is merely a bug? ``` # ./bin/ruby-1.8.7-p374 -e 'p "a".casecmp("[")' 1 # ./bin/ruby-1.9.0-0 -e 'p "a".casecmp("[")' -1 ``` ---------------------------------------- Bug #15816: String#casecmp compares uppercase characters instead of lowercase https://bugs.ruby-lang.org/issues/15816#change-77970 * Author: jonathanhefner (Jonathan Hefner) * Status: Open * Priority: Normal * Assignee: * Target version: * ruby -v: * Backport: 2.4: UNKNOWN, 2.5: UNKNOWN, 2.6: UNKNOWN ---------------------------------------- The current implementation of `String#casecmp` converts characters to uppercase before comparing them. However, all references I've found for `strcasecmp` (the C function on which `String#casecmp` is based) indicate characters should be converted to lowercase before being compared. For example, [this man page](http://manpages.ubuntu.com/manpages/eoan/man3/strcasecmp.3.html) says: > The POSIX.1-2008 standard says ... shall behave as if the strings had been converted to lowercase and then a byte comparison performed. The difference in behavior is apparent when comparing / sorting strings containing `[`, `\`, `]`, `^`, `_`, or `` ` `` (the characters that occur between `Z` and `a`). Converting to lowercase sorts these punctuation characters before `A`-`z` along with most of the other punctuation in ASCII, but converting to uppercase sorts these characters after `A`-`z` instead. ---Files-------------------------------- casecmp-lowercase.patch (1.3 KB) -- https://bugs.ruby-lang.org/ Unsubscribe: