From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: by sourceware.org (Postfix, from userid 48) id A7F1D385DC0E; Wed, 14 Feb 2024 18:27:21 +0000 (GMT) DKIM-Filter: OpenDKIM Filter v2.11.0 sourceware.org A7F1D385DC0E DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=sourceware.org; s=default; t=1707935241; bh=o63ALTMtyFfcusNaJVCBDDlhM2d0pAfHC4akGaZtDC0=; h=From:To:Subject:Date:In-Reply-To:References:From; b=NAcKBibRpaJmZHbW1od2yv6EnIihiKnA3n7NsZmDuWnLdHit7WQAMFqdwwSdbv4Zd UmWDkq5cj3QothvLRcGtVLdph6N5AOfVHHnjlF5Fy4+ahrKlUIqBhejDnVsC4nkYiO lJHpR+qG1PtYcwleXRf7JgsPRuCrgAMH+YNLWJiE= From: "carlos at redhat dot com" To: glibc-bugs@sourceware.org Subject: [Bug localedata/31370] wcwidth() does not treat DEFAULT_IGNORABLE_CODE_POINTs as zero-width Date: Wed, 14 Feb 2024 18:27:21 +0000 X-Bugzilla-Reason: CC X-Bugzilla-Type: changed X-Bugzilla-Watch-Reason: None X-Bugzilla-Product: glibc X-Bugzilla-Component: localedata X-Bugzilla-Version: 2.40 X-Bugzilla-Keywords: X-Bugzilla-Severity: normal X-Bugzilla-Who: carlos at redhat dot com X-Bugzilla-Status: NEW X-Bugzilla-Resolution: X-Bugzilla-Priority: P2 X-Bugzilla-Assigned-To: maiku.fabian at gmail dot com X-Bugzilla-Target-Milestone: --- X-Bugzilla-Flags: X-Bugzilla-Changed-Fields: Message-ID: In-Reply-To: References: Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: quoted-printable X-Bugzilla-URL: http://sourceware.org/bugzilla/ Auto-Submitted: auto-generated MIME-Version: 1.0 List-Id: https://sourceware.org/bugzilla/show_bug.cgi?id=3D31370 --- Comment #4 from Carlos O'Donell --- (In reply to Jules Bertholet from comment #3) > > Please provide a patch to libc-alpha@sourceware.org >=20 > https://sourceware.org/pipermail/libc-alpha/2024-February/154574.html >=20 > > Please also provide justification for the zero width by quoting another= implementation that also provides zero width e.g. CLDR. >=20 > CLDR doesn't address width issues at all, this is defined by Unicode itse= lf. > The Unicode Standard, version 15.0, =C2=A75.21 - Characters Ignored for D= isplay > : What do the libicu APIs return for these characters? > > The list of characters which should be ignored for display in fallback = rendering is given by a character property: Default_Ignorable_Code_Point (D= I). Those characters include almost all format characters, all variation se= lectors, and a few other exceptional characters, such as Hangul fillers. Th= e exact list is defined in DerivedCoreProperties.txt in the Unicode Charact= er Database. >=20 > U+115F HANGUL CHOSEONG FILLER needs a carveout due to the unique behavior= of > the conjoining Korean jamo characters. One composed Hangul "syllable bloc= k" > like =E1=84=91=E1=85=B1=E1=86=B6 is made up of two to three individual co= mponent characters, or > "jamo". These are all assigned an `East_Asian_Width` of `Wide` by Unicode, > which would normally mean they would all be assigned width 2 by glibc; a > combination of (leading choseong jamo) + (medial jungseong jamo) + (trail= ing > jongseong jamo) would then have width 2 + 2 + 2 =3D 6. However, glibc (and > other wcwidth implementations) special-cases jungseong and jongseong, > assigning them all width 0, to ensure that the complete block has width 2= + > 0 + 0 =3D 2 as it should. U+115F is meant for use in syllable blocks that= are > intentionally missing a leading jamo; it must be assigned a width of 2 ev= en > though it has no visible display to ensure that the complete block has wi= dth > 2. Justification like this is *great* to have in the commit message e.g. here = in a v2. https://patchwork.sourceware.org/project/glibc/patch/20240211175840.228824-= 2-julesbertholet@quoi.xyz/ > You can read more about Unicode jamo in the Unicode spec, sections 3.12 > and 18.6 > . --=20 You are receiving this mail because: You are on the CC list for the bug.=