D-Programming-Language/phobos — pull request #2304 by DmitryOlshansky (2014-07-04 21:40:43+00:00)
Title: Fix issue 12455 [reg]Bad lowercase mapping for 'LATIN CAPITAL LETTER I W...

...ITH DOT ABOVE'

Bugzilla: https://issues.dlang.org/show_bug.cgi?id=12455

Also as part of a fix restores a test case in string.d
to exactly match older behaviour.