From patchwork Thu May 26 21:47:21 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Jeff Hostetler X-Patchwork-Id: 12862860 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 9D53CC433F5 for ; Thu, 26 May 2022 21:50:35 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1349366AbiEZVud (ORCPT ); Thu, 26 May 2022 17:50:33 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:34128 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1349297AbiEZVth (ORCPT ); Thu, 26 May 2022 17:49:37 -0400 Received: from mail-wr1-x430.google.com (mail-wr1-x430.google.com [IPv6:2a00:1450:4864:20::430]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id F246EE8BA1 for ; Thu, 26 May 2022 14:49:35 -0700 (PDT) Received: by mail-wr1-x430.google.com with SMTP id p10so3627692wrg.12 for ; Thu, 26 May 2022 14:49:35 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20210112; h=message-id:in-reply-to:references:from:date:subject:fcc :content-transfer-encoding:mime-version:to:cc; bh=cTk9CmwWw4iGOz0CS3tNgQG+VGNLJ2QH91BcLkMnKNg=; b=dK3hBqPDm6zGvHkOKfVQ3guaLFL2NGLVftyaOFeqHnSFlMTee9jMzHfUcDEIVM0d/N 9E9Expi2Nuxec8+ziRNAgTO0oVXY7bD43wPpEtpzl0KnKbqY2DQGs8aulQ2AzKabEsgo GuuXxSipR9aJu3WoPaCag+nV5sZUiCisi6+UoNhgQSxtYlujCr8WmZBNk9dEZxskTe62 7zrIxjidQEa2uFJoL57yiTLRh3IZdox2Z77+tEBkZnmJEFNI7San7UZAV62CBOD5EogC Fe2Z41V8YR1bcGcfYtB6/4GeHlnNrkC0aPs0+4hNK7EYXzjhxlPf2UUBhndifEnqjAon 6tnA== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=x-gm-message-state:message-id:in-reply-to:references:from:date :subject:fcc:content-transfer-encoding:mime-version:to:cc; bh=cTk9CmwWw4iGOz0CS3tNgQG+VGNLJ2QH91BcLkMnKNg=; b=Eqi2RtSbpSWjOfDAqDOYBsNFTIn/CN4Ol/wnh0TGLGyUhx+Iuj9ylHQicwiW0+pMFs pbzHmmYh1rlqBEu9Ik1SiKrMEIfikHfawXnHTDGR7Gm/G79vXM+M7/2IpPh+aoKnV7Ev pS8TmDPul+BLpTBY0sc1lgQvvGMEsVQOsgLjnsh7rlHrfcJ8aRD+RHuEwCOKB+Z4K4k7 qW+7whcjOO6zz7MivRzSJq6CJLfWwTYEjbdTtmBYlBQSAxvjusjWCMfASLtMcHHonbP9 1/mE6E9cLQ+QFwC1gpmETVNO72Haj5uCqRVt7zHnEoE/+bDD8EyfLyeyfKHlWQVFVIyj 0htQ== X-Gm-Message-State: AOAM531q/NfCXCdpOdNWeOsxZC3wYWDP9QM2v+9AK8nkNFjuO2b9QTKD o5aKmwU4Rmv3y9zR2KZunKxYukVmwgI= X-Google-Smtp-Source: ABdhPJzeFJLVltElqHWux/QKYcvGaMW7m68h2NFYKBy6Lrnd5sGSA0d1QxdJkJRl9f1dLiDkeFAY9A== X-Received: by 2002:adf:fb4c:0:b0:20f:d4e7:b84f with SMTP id c12-20020adffb4c000000b0020fd4e7b84fmr19531533wrs.406.1653601774032; Thu, 26 May 2022 14:49:34 -0700 (PDT) Received: from [127.0.0.1] ([13.74.141.28]) by smtp.gmail.com with ESMTPSA id s22-20020a1cf216000000b003974ba5cacdsm223662wmc.35.2022.05.26.14.49.33 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Thu, 26 May 2022 14:49:33 -0700 (PDT) Message-Id: In-Reply-To: References: Date: Thu, 26 May 2022 21:47:21 +0000 Subject: [PATCH v9 27/30] t/lib-unicode-nfc-nfd: helper prereqs for testing unicode nfc/nfd Fcc: Sent MIME-Version: 1.0 To: git@vger.kernel.org Cc: Jeff Hostetler , Derrick Stolee , =?utf-8?b?w4Z2YXIgQXJuZmrDtnI=?= =?utf-8?b?w7A=?= Bjarmason , Torsten =?unknown-8bit?q?B?= =?unknown-8bit?q?=C3=B6gershausen?= , rsbecker@nexbridge.com, Bagas Sanjaya , Johannes Schindelin , Jeff Hostetler , Jeff Hostetler Precedence: bulk List-ID: X-Mailing-List: git@vger.kernel.org From: Jeff Hostetler From: Jeff Hostetler Create a set of prereqs to help understand how file names are handled by the filesystem when they contain NFC and NFD Unicode characters. Signed-off-by: Jeff Hostetler --- t/lib-unicode-nfc-nfd.sh | 162 +++++++++++++++++++++++++++++++++++++++ 1 file changed, 162 insertions(+) create mode 100755 t/lib-unicode-nfc-nfd.sh diff --git a/t/lib-unicode-nfc-nfd.sh b/t/lib-unicode-nfc-nfd.sh new file mode 100755 index 00000000000..22232247efc --- /dev/null +++ b/t/lib-unicode-nfc-nfd.sh @@ -0,0 +1,162 @@ +# Help detect how Unicode NFC and NFD are handled on the filesystem. + +# A simple character that has a NFD form. +# +# NFC: U+00e9 LATIN SMALL LETTER E WITH ACUTE +# UTF8(NFC): \xc3 \xa9 +# +# NFD: U+0065 LATIN SMALL LETTER E +# U+0301 COMBINING ACUTE ACCENT +# UTF8(NFD): \x65 + \xcc \x81 +# +utf8_nfc=$(printf "\xc3\xa9") +utf8_nfd=$(printf "\x65\xcc\x81") + +# Is the OS or the filesystem "Unicode composition sensitive"? +# +# That is, does the OS or the filesystem allow files to exist with +# both the NFC and NFD spellings? Or, does the OS/FS lie to us and +# tell us that the NFC and NFD forms are equivalent. +# +# This is or may be independent of what type of filesystem we have, +# since it might be handled by the OS at a layer above the FS. +# Testing shows on MacOS using APFS, HFS+, and FAT32 reports a +# collision, for example. +# +# This does not tell us how the Unicode pathname will be spelled +# on disk, but rather only that the two spelling "collide". We +# will examine the actual on disk spelling in a later prereq. +# +test_lazy_prereq UNICODE_COMPOSITION_SENSITIVE ' + mkdir trial_${utf8_nfc} && + mkdir trial_${utf8_nfd} +' + +# Is the spelling of an NFC pathname preserved on disk? +# +# On MacOS with HFS+ and FAT32, NFC paths are converted into NFD +# and on APFS, NFC paths are preserved. As we have established +# above, this is independent of "composition sensitivity". +# +test_lazy_prereq UNICODE_NFC_PRESERVED ' + mkdir c_${utf8_nfc} && + ls | test-tool hexdump >dump && + grep "63 5f c3 a9" dump +' + +# Is the spelling of an NFD pathname preserved on disk? +# +test_lazy_prereq UNICODE_NFD_PRESERVED ' + mkdir d_${utf8_nfd} && + ls | test-tool hexdump >dump && + grep "64 5f 65 cc 81" dump +' + +# The following _DOUBLE_ forms are more for my curiosity, +# but there may be quirks lurking when there are multiple +# combining characters in non-canonical order. + +# Unicode also allows multiple combining characters +# that can be decomposed in pieces. +# +# NFC: U+1f67 GREEK SMALL LETTER OMEGA WITH DASIA AND PERISPOMENI +# UTF8(NFC): \xe1 \xbd \xa7 +# +# NFD1: U+1f61 GREEK SMALL LETTER OMEGA WITH DASIA +# U+0342 COMBINING GREEK PERISPOMENI +# UTF8(NFD1): \xe1 \xbd \xa1 + \xcd \x82 +# +# But U+1f61 decomposes into +# NFD2: U+03c9 GREEK SMALL LETTER OMEGA +# U+0314 COMBINING REVERSED COMMA ABOVE +# UTF8(NFD2): \xcf \x89 + \xcc \x94 +# +# Yielding: \xcf \x89 + \xcc \x94 + \xcd \x82 +# +# Note that I've used the canonical ordering of the +# combinining characters. It is also possible to +# swap them. My testing shows that that non-standard +# ordering also causes a collision in mkdir. However, +# the resulting names don't draw correctly on the +# terminal (implying that the on-disk format also has +# them out of order). +# +greek_nfc=$(printf "\xe1\xbd\xa7") +greek_nfd1=$(printf "\xe1\xbd\xa1\xcd\x82") +greek_nfd2=$(printf "\xcf\x89\xcc\x94\xcd\x82") + +# See if a double decomposition also collides. +# +test_lazy_prereq UNICODE_DOUBLE_COMPOSITION_SENSITIVE ' + mkdir trial_${greek_nfc} && + mkdir trial_${greek_nfd2} +' + +# See if the NFC spelling appears on the disk. +# +test_lazy_prereq UNICODE_DOUBLE_NFC_PRESERVED ' + mkdir c_${greek_nfc} && + ls | test-tool hexdump >dump && + grep "63 5f e1 bd a7" dump +' + +# See if the NFD spelling appears on the disk. +# +test_lazy_prereq UNICODE_DOUBLE_NFD_PRESERVED ' + mkdir d_${greek_nfd2} && + ls | test-tool hexdump >dump && + grep "64 5f cf 89 cc 94 cd 82" dump +' + +# The following is for debugging. I found it useful when +# trying to understand the various (OS, FS) quirks WRT +# Unicode and how composition/decomposition is handled. +# For example, when trying to understand how (macOS, APFS) +# and (macOS, HFS) and (macOS, FAT32) compare. +# +# It is rather noisy, so it is disabled by default. +# +if test "$unicode_debug" = "true" +then + if test_have_prereq UNICODE_COMPOSITION_SENSITIVE + then + echo NFC and NFD are distinct on this OS/filesystem. + else + echo NFC and NFD are aliases on this OS/filesystem. + fi + + if test_have_prereq UNICODE_NFC_PRESERVED + then + echo NFC maintains original spelling. + else + echo NFC is modified. + fi + + if test_have_prereq UNICODE_NFD_PRESERVED + then + echo NFD maintains original spelling. + else + echo NFD is modified. + fi + + if test_have_prereq UNICODE_DOUBLE_COMPOSITION_SENSITIVE + then + echo DOUBLE NFC and NFD are distinct on this OS/filesystem. + else + echo DOUBLE NFC and NFD are aliases on this OS/filesystem. + fi + + if test_have_prereq UNICODE_DOUBLE_NFC_PRESERVED + then + echo Double NFC maintains original spelling. + else + echo Double NFC is modified. + fi + + if test_have_prereq UNICODE_DOUBLE_NFD_PRESERVED + then + echo Double NFD maintains original spelling. + else + echo Double NFD is modified. + fi +fi