#! /bin/sh

# Test whether \s matches SP and UTF-8 multi-byte white space characters.

#

# Copyright (C) 2013-2017 Free Software Foundation, Inc.

#

# Copying and distribution of this file, with or without modification,

# are permitted in any medium without royalty provided the copyright

# notice and this notice are preserved.

. "${srcdir=.}/init.sh"; path_prepend_ ../src

require_en_utf8_locale_

LC_ALL=en_US.UTF-8

export LC_ALL

# It would have been nice to be able to use all UTF8 characters

# with the Unicode WSpace=Y character property,

# https://en.wikipedia.org/wiki/Whitespace_character, but that

# would currently cause distracting failures everywhere I've tried.

# Instead, I've listed each with an indicator column, telling what

# this test should do if the system's locale/tools produce the

# wrong answer.

# The values in that column:

# X required on all systems (fail if \s or \S fail to work as expected)

# x required on "modern enough" systems

# O optional: \s or \S misbehavior elicits a warning, but never failure

utf8_space_characters=$(sed 's/.*: *//;s/  */\\x/g' <<\EOF

U+0009 Horizontal Tab:            X 09

U+000A Line feed:                 O 0a

U+000B Vertical Tab:              X 0b

U+000C Form feed:                 X 0c

U+000D Carriage return:           X 0d

U+0020 SPACE:                     X 20

U+0085 Next line:                 O 85

U+00A0 NO-BREAK SPACE:            O c2 a0

U+1680 OGHAM SPACE MARK:          x e1 9a 80

U+2000 EN QUAD:                   x e2 80 80

U+2001 EM QUAD:                   x e2 80 81

U+2002 EN SPACE:                  x e2 80 82

U+2003 EM SPACE:                  x e2 80 83

U+2004 THREE-PER-EM SPACE:        x e2 80 84

U+2005 FOUR-PER-EM SPACE:         x e2 80 85

U+2006 SIX-PER-EM SPACE:          x e2 80 86

U+2007 FIGURE SPACE:              O e2 80 87

U+2008 PUNCTUATION SPACE:         x e2 80 88

U+2009 THIN SPACE:                x e2 80 89

U+200A HAIR SPACE:                x e2 80 8a

U+200B ZERO WIDTH SPACE:          O e2 80 8b

U+202F NARROW NO-BREAK SPACE:     O e2 80 af

U+205F MEDIUM MATHEMATICAL SPACE: x e2 81 9f

U+3000 IDEOGRAPHIC SPACE:         x e3 80 80

EOF

)

fail=0

# On systems that are not "modern enough," simply warn when an "x"-marked

# character is not classified as white space.  Too many systems

# have inadequate UTF-8 tables in this respect, and that lack should not

# discourage/confuse those who consider whether to install grep.

# As for what constitutes "modern enough", I've arbitrarily started

# with "Fedora 20 or newer".  Tested additions welcome.

modern_enough=0

grep -iE 'fedora release [2-9][0-9]+\b' /etc/redhat-release >/dev/null 2>&1 \

  && modern_enough=1

for i in $utf8_space_characters; do

  eval 'fail() { fail=1; }'

  m=ERROR

  case $i in

      X*) ;;

      x*) test $modern_enough = 1 || { eval 'fail() { :; }'; m=warning; } ;;

      O*) m=warning; eval 'fail() { :; }' ;;

      *) warn_ "unexpected prefix: $i"; exit 1 ;;

  esac

  # Strip the prefix byte.

  i=${i#?}

  hex_printf_ "$i" | grep -q '^\s$' \

      || { warn_ " $m: \\s failed to match $i in the $LC_ALL locale"; fail; }

  hex_printf_ "$i" | returns_ 1 grep -q '\S' \

      || { warn_ " $m: \\S mistakenly matched $i in the $LC_ALL locale"; fail; }

done

# This is a separate test, only nominally related to \s.

# It is solely to get coverage of a code path (exercising dfa.c's

# match_mb_charset function) that would have otherwise been untouched.

# However, as of the change-set adding this new test, match_mb_charset

# is unreachable via grep.

printf '\0' | returns_ 1 grep -aE '^\s?$' > out 2>&1 || fail=1

compare /dev/null out

Exit $fail