From patchwork Tue Mar 8 22:15:25 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Jeff Hostetler X-Patchwork-Id: 12774466 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 DC1C4C433FE for ; Tue, 8 Mar 2022 22:16:39 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1350706AbiCHWRf (ORCPT ); Tue, 8 Mar 2022 17:17:35 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:51500 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1350724AbiCHWRA (ORCPT ); Tue, 8 Mar 2022 17:17:00 -0500 Received: from mail-wr1-x42c.google.com (mail-wr1-x42c.google.com [IPv6:2a00:1450:4864:20::42c]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id EDCC758390 for ; Tue, 8 Mar 2022 14:15:56 -0800 (PST) Received: by mail-wr1-x42c.google.com with SMTP id r10so271170wrp.3 for ; Tue, 08 Mar 2022 14:15:56 -0800 (PST) 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=mvnJNku/ci6QCsp+2rYRjooUfFEeT0Zt7IFMOmtffic=; b=KiK6Xnrx5tcrRCkxoWdx9nvv/sRLIJMeuYHZ3GNqQuNSwDsKwLl0NGgvYccPZhqj1c 15CNQWuldzJk0HK8Y3yoeaYSPae2Aa4j9jJqyc0AOudmO8Ksc3RsMi2VC3PoMrikJyzp MGJKa5PmMMULbIPXB41DnVU+BHzPJZbcJQnOP+NHC/eyjm+I2Ls8F3CEVW+HzBkH8gOx s9Ekf4gQGEWDu1CpxB2+U3nQf50BZkVugq+VKrsTfzFV/mBM7qDe6h+gJsqfLPVRIrcy DwAFcxBzearMeVOxWwmMOXc+m9IJqyES0PxbYVjrvAKSHKQKMwRjChjd4L87Tn1SlxsS /TXw== 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=mvnJNku/ci6QCsp+2rYRjooUfFEeT0Zt7IFMOmtffic=; b=qB+Vg1glYUEEiDF/4eY/EfLeykf1f8g+u+QeUzemsiEFPD4zXtm4zV8OQisxfQNz8J mjKguZZfQSqXGtPp8igbzS6B+NWbEHPiist5GIutRthyFTnG7L/FU0OoFeu67anwghI2 Lgd7bK4OPQIkrJ+coVIr4TSJk51aFoi4XTBc8D//75EEacDt3Y41iXc01SHBCX9afqz/ x+QN/VzWilw0fmiw9DIaEf0HXNeDvxAvep/y612+hMfHwxcbEb9AwWm4vw6TUSAKGS1C E54ho/ZiHEMrpneEVuutbTNpL1DvNOrmxk/NWnZp7Xkk99tlhZoSjgg8bIQ6F+djm1t6 i9ng== X-Gm-Message-State: AOAM531S5qxHeP1FNrE87BLI9gwU47JQM6fbL+DmKsYQOeieeUFAS9Xj IsLMd7m6HUcfxy3BIwAjZM/WqGxYLM4= X-Google-Smtp-Source: ABdhPJxW8xyLCO4cr97JqU8eTI/Z/MQKlTPClWvayiz9UtDx2h8iAtxCh0DcW9hLohQVha18zGznVg== X-Received: by 2002:a5d:6c61:0:b0:203:70ec:e77c with SMTP id r1-20020a5d6c61000000b0020370ece77cmr3129349wrz.692.1646777755353; Tue, 08 Mar 2022 14:15:55 -0800 (PST) Received: from [127.0.0.1] ([13.74.141.28]) by smtp.gmail.com with ESMTPSA id f11-20020a7bcc0b000000b0037e0c362b6dsm62079wmh.31.2022.03.08.14.15.54 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Tue, 08 Mar 2022 14:15:54 -0800 (PST) Message-Id: <5a0c1b7a2873accc6db4b34493962378819eacd4.1646777728.git.gitgitgadget@gmail.com> In-Reply-To: References: Date: Tue, 08 Mar 2022 22:15:25 +0000 Subject: [PATCH v2 25/27] 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?= , 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 | 159 +++++++++++++++++++++++++++++++++++++++ 1 file changed, 159 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..a09e910c302 --- /dev/null +++ b/t/lib-unicode-nfc-nfd.sh @@ -0,0 +1,159 @@ +# 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". +# +# 0000000 63 5f c3 a9 +# +# (/usr/bin/od output contains different amount of whitespace +# on different platforms, so we need the wildcards here.) +# +test_lazy_prereq UNICODE_NFC_PRESERVED ' + mkdir c_${utf8_nfc} && + ls | od -t x1 | grep "63 *5f *c3 *a9" +' + +# Is the spelling of an NFD pathname preserved on disk? +# +# 0000000 64 5f 65 cc 81 +# +test_lazy_prereq UNICODE_NFD_PRESERVED ' + mkdir d_${utf8_nfd} && + ls | od -t x1 | grep "64 *5f *65 *cc *81" +' + mkdir c_${utf8_nfc} && + mkdir d_${utf8_nfd} && + +# 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 | od -t x1 | grep "63 *5f *e1 *bd *a7" +' + +# See if the NFD spelling appears on the disk. +# +test_lazy_prereq UNICODE_DOUBLE_NFD_PRESERVED ' + mkdir d_${greek_nfd2} && + ls | od -t x1 | grep "64 *5f *cf *89 *cc *94 *cd *82" +' + +if test $unicode_debug = 1 +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