From 5023698ddfa5227fa5c5952b7ddd3b6a6009e591 Mon Sep 17 00:00:00 2001
From: Niko Tyni <ntyni@debian.org>
Date: Tue, 19 Oct 2010 21:55:14 +0300
Subject: [PATCH] LC_NUMERIC documentation updates

Most of the confusion around LC_NUMERIC was fixed with commits
7e4353e96785be675a69a6886d154405dbfdc124 and
2095dafae09cfface71d4202b3188926ea0ccc1c
but two errors remain:

- the early parts of perllocale.pod still say printf() uses LC_NUMERIC
  with just 'use locale' when actually a POSIX::setlocale() call is
  also needed

- format() hasn't used LC_NUMERIC unconditionally since 5.005_03
  (commit 097ee67dff1c60f201bc09435bc6eaeeafcd8123).
---
 pod/perlform.pod   |   20 ++++++++------------
 pod/perllocale.pod |   15 ++++++---------
 2 files changed, 14 insertions(+), 21 deletions(-)

diff --git a/pod/perlform.pod b/pod/perlform.pod
index 3cfa1b7..df0f0a1 100644
--- a/pod/perlform.pod
+++ b/pod/perlform.pod
@@ -166,9 +166,9 @@ token on the first line.  If an expression evaluates to a number with a
 decimal part, and if the corresponding picture specifies that the decimal
 part should appear in the output (that is, any picture except multiple "#"
 characters B<without> an embedded "."), the character used for the decimal
-point is B<always> determined by the current LC_NUMERIC locale.  This
-means that, if, for example, the run-time environment happens to specify a
-German locale, "," will be used instead of the default ".".  See
+point is determined by the current LC_NUMERIC locale if C<use locale> is in
+effect.  This means that, if, for example, the run-time environment happens
+to specify a German locale, "," will be used instead of the default ".".  See
 L<perllocale> and L<"WARNINGS"> for more information.
 
 
@@ -442,15 +442,11 @@ Lexical variables (declared with "my") are not visible within a
 format unless the format is declared within the scope of the lexical
 variable.  (They weren't visible at all before version 5.001.)
 
-Formats are the only part of Perl that unconditionally use information
-from a program's locale; if a program's environment specifies an
-LC_NUMERIC locale, it is always used to specify the decimal point
-character in formatted output.  Perl ignores all other aspects of locale
-handling unless the C<use locale> pragma is in effect.  Formatted output
-cannot be controlled by C<use locale> because the pragma is tied to the
-block structure of the program, and, for historical reasons, formats
-exist outside that block structure.  See L<perllocale> for further
-discussion of locale handling.
+If a program's environment specifies an LC_NUMERIC locale and C<use
+locale> is in effect when the format is declared, the locale is used
+to specify the decimal point character in formatted output.  Formatted
+output cannot be controlled by C<use locale> at the time when write()
+is called. See L<perllocale> for further discussion of locale handling.
 
 Within strings that are to be displayed in a fixed length text field,
 each control character is substituted by a space. (But remember the
diff --git a/pod/perllocale.pod b/pod/perllocale.pod
index 0dbabe7..0bec423 100644
--- a/pod/perllocale.pod
+++ b/pod/perllocale.pod
@@ -115,8 +115,7 @@ ucfirst(), and lcfirst()) use C<LC_CTYPE>
 
 =item *
 
-B<The formatting functions> (printf(), sprintf() and write()) use
-C<LC_NUMERIC>
+B<Format declarations> (format()) use C<LC_NUMERIC>
 
 =item *
 
@@ -967,13 +966,11 @@ system's implementation of the locale system than by Perl.
 
 =head2 write() and LC_NUMERIC
 
-Formats are the only part of Perl that unconditionally use information
-from a program's locale; if a program's environment specifies an
-LC_NUMERIC locale, it is always used to specify the decimal point
-character in formatted output.  Formatted output cannot be controlled by
-C<use locale> because the pragma is tied to the block structure of the
-program, and, for historical reasons, formats exist outside that block
-structure.
+If a program's environment specifies an LC_NUMERIC locale and C<use
+locale> is in effect when the format is declared, the locale is used
+to specify the decimal point character in formatted output.  Formatted
+output cannot be controlled by C<use locale> at the time when write()
+is called.
 
 =head2 Freely available locale definitions
 
-- 
1.7.1

From 8fe1e0991520cf973f8fd5d492e8d0750a681e93 Mon Sep 17 00:00:00 2001
From: Niko Tyni <ntyni@debian.org>
Date: Wed, 27 Oct 2010 09:49:38 +0300
Subject: [PATCH 1/2] Refactor LC_NUMERIC test out of t/run/fresh_perl.t

Neither lib/locale.t nor t/run/fresh_perl.t should be used for new tests,
so take the locale related tests and the setup code from fresh_perl.t
to make ground for more.
---
 MANIFEST           |    1 +
 t/run/fresh_perl.t |   36 ------------------------------------
 t/run/locale.t     |   50 ++++++++++++++++++++++++++++++++++++++++++++++++++
 3 files changed, 51 insertions(+), 36 deletions(-)
 create mode 100644 t/run/locale.t

diff --git a/MANIFEST b/MANIFEST
index a69f37a..2f83e7f 100644
--- a/MANIFEST
+++ b/MANIFEST
@@ -4801,6 +4801,7 @@ t/re/uniprops.t			Test unicode \p{} regex constructs
 t/run/cloexec.t			Test close-on-exec.
 t/run/exit.t			Test perl's exit status.
 t/run/fresh_perl.t		Tests that require a fresh perl.
+t/run/locale.t		Tests related to locale handling
 t/run/noswitch.t		Test aliasing ARGV for other switch tests
 t/run/runenv.t			Test if perl honors its environment variables.
 t/run/script.t			See if script invocation works
diff --git a/t/run/fresh_perl.t b/t/run/fresh_perl.t
index 3666f09..927d7f6 100644
--- a/t/run/fresh_perl.t
+++ b/t/run/fresh_perl.t
@@ -565,42 +565,6 @@ EOT
 EXPECT
 ok
 ########
-# This test is here instead of lib/locale.t because
-# the bug depends on in the internal state of the locale
-# settings and pragma/locale messes up that state pretty badly.
-# We need a "fresh run".
-BEGIN {
-    eval { require POSIX };
-    if ($@) {
-	exit(0); # running minitest?
-    }
-}
-use Config;
-my $have_setlocale = $Config{d_setlocale} eq 'define';
-$have_setlocale = 0 if $@;
-# Visual C's CRT goes silly on strings of the form "en_US.ISO8859-1"
-# and mingw32 uses said silly CRT
-$have_setlocale = 0 if (($^O eq 'MSWin32' || $^O eq 'NetWare') && $Config{cc} =~ /^(cl|gcc)/i);
-exit(0) unless $have_setlocale;
-my @locales;
-if (-x "/usr/bin/locale" && open(LOCALES, "/usr/bin/locale -a 2>/dev/null|")) {
-    while(<LOCALES>) {
-        chomp;
-        push(@locales, $_);
-    }
-    close(LOCALES);
-}
-exit(0) unless @locales;
-for (@locales) {
-    use POSIX qw(locale_h);
-    use locale;
-    setlocale(LC_NUMERIC, $_) or next;
-    my $s = sprintf "%g %g", 3.1, 3.1;
-    next if $s eq '3.1 3.1' || $s =~ /^(3.+1) \1$/;
-    print "$_ $s\n";
-}
-EXPECT
-########
 # [ID 20001202.002] and change #8066 added 'at -e line 1';
 # reversed again as a result of [perl #17763]
 die qr(x)
diff --git a/t/run/locale.t b/t/run/locale.t
new file mode 100644
index 0000000..9f9d32c
--- /dev/null
+++ b/t/run/locale.t
@@ -0,0 +1,50 @@
+#!./perl
+BEGIN {
+    chdir 't' if -d 't';
+    @INC = '../lib';
+    require './test.pl';    # for fresh_perl_is() etc
+}
+
+use strict;
+
+########
+# This test is here instead of lib/locale.t because
+# the bug depends on in the internal state of the locale
+# settings and pragma/locale messes up that state pretty badly.
+# We need a "fresh run".
+BEGIN {
+    eval { require POSIX };
+    if ($@) {
+	skip_all("could not load the POSIX module"); # running minitest?
+    }
+}
+use Config;
+my $have_setlocale = $Config{d_setlocale} eq 'define';
+$have_setlocale = 0 if $@;
+# Visual C's CRT goes silly on strings of the form "en_US.ISO8859-1"
+# and mingw32 uses said silly CRT
+$have_setlocale = 0 if (($^O eq 'MSWin32' || $^O eq 'NetWare') && $Config{cc} =~ /^(cl|gcc)/i);
+skip_all("no setlocale available") unless $have_setlocale;
+my @locales;
+if (-x "/usr/bin/locale" && open(LOCALES, "/usr/bin/locale -a 2>/dev/null|")) {
+    while(<LOCALES>) {
+        chomp;
+        push(@locales, $_);
+    }
+    close(LOCALES);
+}
+skip_all("no locales available") unless @locales;
+
+plan tests => &last;
+fresh_perl_is("for (qw(@locales)) {\n" . <<'EOF',
+    use POSIX qw(locale_h);
+    use locale;
+    setlocale(LC_NUMERIC, "$_") or next;
+    my $s = sprintf "%g %g", 3.1, 3.1;
+    next if $s eq '3.1 3.1' || $s =~ /^(3.+1) \1$/;
+    print "$_ $s\n";
+}
+EOF
+    "", {}, "no locales where LC_NUMERIC breaks");
+
+sub last { 1 }
-- 
1.7.2.3

From 954257213d7277918ce61eac4edf7dbced233c62 Mon Sep 17 00:00:00 2001
From: Niko Tyni <ntyni@debian.org>
Date: Tue, 19 Oct 2010 21:55:14 +0300
Subject: [PATCH 2/2] LC_NUMERIC documentation updates + tests

Most of the confusion around LC_NUMERIC was fixed with commits
7e4353e96785be675a69a6886d154405dbfdc124 and
2095dafae09cfface71d4202b3188926ea0ccc1c
but two errors remain:

- the early parts of perllocale.pod still say printf() uses LC_NUMERIC
  with just 'use locale' when actually a POSIX::setlocale() call is
  also needed

- format() hasn't used LC_NUMERIC unconditionally since 5.005_03
  (commit 097ee67dff1c60f201bc09435bc6eaeeafcd8123).

Update the documentation and test the claims in t/run/locale.t.
---
 pod/perlform.pod   |   20 ++++-------
 pod/perllocale.pod |   15 +++-----
 t/run/locale.t     |   93 +++++++++++++++++++++++++++++++++++++++++++++++++---
 3 files changed, 102 insertions(+), 26 deletions(-)

diff --git a/pod/perlform.pod b/pod/perlform.pod
index 3cfa1b7..df0f0a1 100644
--- a/pod/perlform.pod
+++ b/pod/perlform.pod
@@ -166,9 +166,9 @@ token on the first line.  If an expression evaluates to a number with a
 decimal part, and if the corresponding picture specifies that the decimal
 part should appear in the output (that is, any picture except multiple "#"
 characters B<without> an embedded "."), the character used for the decimal
-point is B<always> determined by the current LC_NUMERIC locale.  This
-means that, if, for example, the run-time environment happens to specify a
-German locale, "," will be used instead of the default ".".  See
+point is determined by the current LC_NUMERIC locale if C<use locale> is in
+effect.  This means that, if, for example, the run-time environment happens
+to specify a German locale, "," will be used instead of the default ".".  See
 L<perllocale> and L<"WARNINGS"> for more information.
 
 
@@ -442,15 +442,11 @@ Lexical variables (declared with "my") are not visible within a
 format unless the format is declared within the scope of the lexical
 variable.  (They weren't visible at all before version 5.001.)
 
-Formats are the only part of Perl that unconditionally use information
-from a program's locale; if a program's environment specifies an
-LC_NUMERIC locale, it is always used to specify the decimal point
-character in formatted output.  Perl ignores all other aspects of locale
-handling unless the C<use locale> pragma is in effect.  Formatted output
-cannot be controlled by C<use locale> because the pragma is tied to the
-block structure of the program, and, for historical reasons, formats
-exist outside that block structure.  See L<perllocale> for further
-discussion of locale handling.
+If a program's environment specifies an LC_NUMERIC locale and C<use
+locale> is in effect when the format is declared, the locale is used
+to specify the decimal point character in formatted output.  Formatted
+output cannot be controlled by C<use locale> at the time when write()
+is called. See L<perllocale> for further discussion of locale handling.
 
 Within strings that are to be displayed in a fixed length text field,
 each control character is substituted by a space. (But remember the
diff --git a/pod/perllocale.pod b/pod/perllocale.pod
index 0dbabe7..0bec423 100644
--- a/pod/perllocale.pod
+++ b/pod/perllocale.pod
@@ -115,8 +115,7 @@ ucfirst(), and lcfirst()) use C<LC_CTYPE>
 
 =item *
 
-B<The formatting functions> (printf(), sprintf() and write()) use
-C<LC_NUMERIC>
+B<Format declarations> (format()) use C<LC_NUMERIC>
 
 =item *
 
@@ -967,13 +966,11 @@ system's implementation of the locale system than by Perl.
 
 =head2 write() and LC_NUMERIC
 
-Formats are the only part of Perl that unconditionally use information
-from a program's locale; if a program's environment specifies an
-LC_NUMERIC locale, it is always used to specify the decimal point
-character in formatted output.  Formatted output cannot be controlled by
-C<use locale> because the pragma is tied to the block structure of the
-program, and, for historical reasons, formats exist outside that block
-structure.
+If a program's environment specifies an LC_NUMERIC locale and C<use
+locale> is in effect when the format is declared, the locale is used
+to specify the decimal point character in formatted output.  Formatted
+output cannot be controlled by C<use locale> at the time when write()
+is called.
 
 =head2 Freely available locale definitions
 
diff --git a/t/run/locale.t b/t/run/locale.t
index 9f9d32c..483123f 100644
--- a/t/run/locale.t
+++ b/t/run/locale.t
@@ -8,12 +8,12 @@ BEGIN {
 use strict;
 
 ########
-# This test is here instead of lib/locale.t because
-# the bug depends on in the internal state of the locale
+# These tests are here instead of lib/locale.t because
+# some bugs depend on in the internal state of the locale
 # settings and pragma/locale messes up that state pretty badly.
-# We need a "fresh run".
+# We need "fresh runs".
 BEGIN {
-    eval { require POSIX };
+    eval { require POSIX; POSIX->import("locale_h") };
     if ($@) {
 	skip_all("could not load the POSIX module"); # running minitest?
     }
@@ -47,4 +47,87 @@ fresh_perl_is("for (qw(@locales)) {\n" . <<'EOF',
 EOF
     "", {}, "no locales where LC_NUMERIC breaks");
 
-sub last { 1 }
+fresh_perl_is("for (qw(@locales)) {\n" . <<'EOF',
+    use POSIX qw(locale_h);
+    use locale;
+    my $in = 4.2;
+    my $s = sprintf "%g", $in; # avoid any constant folding bugs
+    next if $s eq "4.2";
+    print "$_ $s\n";
+}
+EOF
+    "", {}, "LC_NUMERIC without setlocale() has no effect in any locale");
+
+# try to find out a locale where LC_NUMERIC makes a difference
+my $original_locale = setlocale(LC_NUMERIC);
+
+my ($base, $different, $difference);
+for ("C", @locales) { # prefer C for the base if available
+    use locale;
+    setlocale(LC_NUMERIC, $_) or next;
+    my $in = 4.2; # avoid any constant folding bugs
+    if ((my $s = sprintf("%g", $in)) eq "4.2")  {
+	$base ||= $_;
+    } else {
+	$different ||= $_;
+	$difference ||= $s;
+    }
+
+    last if $base && $different;
+}
+setlocale(LC_NUMERIC, $original_locale);
+
+SKIP: {
+    skip("no locale available where LC_NUMERIC makes a difference", &last - 2)
+	if !$different;
+    note("using the '$different' locale for LC_NUMERIC tests");
+    for ($different) {
+	local $ENV{LC_NUMERIC} = $_;
+	local $ENV{LC_ALL}; # so it never overrides LC_NUMERIC
+
+	fresh_perl_is(<<'EOF', "4.2", {},
+format STDOUT =
+@.#
+4.179
+.
+write;
+EOF
+	    "format() does not look at LC_NUMERIC without 'use locale'");
+
+        {
+	    fresh_perl_is(<<'EOF', $difference, {},
+use locale;
+format STDOUT =
+@.#
+4.179
+.
+write;
+EOF
+	    "format() looks at LC_NUMERIC with 'use locale'");
+        }
+
+        {
+	    fresh_perl_is(<<'EOF', "4.2", {},
+format STDOUT =
+@.#
+4.179
+.
+{ use locale; write; }
+EOF
+	    "too late to look at the locale at write() time");
+        }
+
+        {
+	    fresh_perl_is(<<'EOF', $difference, {},
+use locale; format STDOUT =
+@.#
+4.179
+.
+{ no locale; write; }
+EOF
+	    "too late to ignore the locale at write() time");
+        }
+    }
+} # SKIP
+
+sub last { 6 }
-- 
1.7.2.3