From 21c24a73e0b36f89878627b6f4ea9d2ff13eaa42 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?K=C5=8Dan?= <koan.bot@atoomic.org>
Date: Thu, 7 May 2026 06:49:00 -0600
Subject: [PATCH] =?UTF-8?q?fix:=20@Dsuf=20arrays=20too=20short=20=E2=80=94?=
 =?UTF-8?q?=20format=5Fo=20drops=20suffix=20for=20day=2031?=
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20 language modules had @Dsuf with only 31 elements (indices 0-30).
format_o accesses $dsuf->[$day] where $day is 1-31, so day 31
reads index 31 which was undef — producing "31" with no suffix
and an uninitialized value warning.

Visible in 8 modules without format_o overrides (Romanian, Amharic,
Tigrinya, TigrinyaEritrean, TigrinyaEthiopian, Arabic, Occitan,
Spanish). The remaining 12 modules had the same short array but
were masked by custom format_o implementations.

Fix: extend all @Dsuf arrays to 32 elements. Tighten the
lang-data.t validation threshold from >= 31 to >= 32 and add
a regression test exercising format_o on day 31 for every language.

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>
---
 lib/Date/Language/Amharic.pm           |  4 ++--
 lib/Date/Language/Arabic.pm            |  2 +-
 lib/Date/Language/Chinese.pm           |  2 +-
 lib/Date/Language/Chinese_GB.pm        |  2 +-
 lib/Date/Language/Czech.pm             |  2 +-
 lib/Date/Language/Dutch.pm             |  2 +-
 lib/Date/Language/Finnish.pm           |  2 +-
 lib/Date/Language/Greek.pm             |  2 +-
 lib/Date/Language/Hungarian.pm         |  2 +-
 lib/Date/Language/Occitan.pm           |  2 +-
 lib/Date/Language/Romanian.pm          |  2 +-
 lib/Date/Language/Russian.pm           |  2 +-
 lib/Date/Language/Russian_cp1251.pm    |  2 +-
 lib/Date/Language/Russian_koi8r.pm     |  2 +-
 lib/Date/Language/Spanish.pm           |  2 +-
 lib/Date/Language/Swedish.pm           |  2 +-
 lib/Date/Language/Tigrinya.pm          |  2 +-
 lib/Date/Language/TigrinyaEritrean.pm  |  4 ++--
 lib/Date/Language/TigrinyaEthiopian.pm |  4 ++--
 lib/Date/Language/Turkish.pm           |  2 +-
 t/lang-data.t                          | 19 ++++++++++++++++++-
 21 files changed, 41 insertions(+), 24 deletions(-)

diff --git a/lib/Date/Language/Amharic.pm b/lib/Date/Language/Amharic.pm
index 95e62d8..bb6b9e8 100644
--- a/lib/Date/Language/Amharic.pm
+++ b/lib/Date/Language/Amharic.pm
@@ -43,7 +43,7 @@ if ( $] >= 5.006 ) {
 @MoYs = map { substr($_,0,3) } @MoY;
 @AMPM = ( "\x{1320}\x{12cb}\x{1275}", "\x{12a8}\x{1230}\x{12d3}\x{1275}" );
 
-@Dsuf = ("\x{129b}") x 31;
+@Dsuf = ("\x{129b}") x 32;
 }
 else {
 @DoW = (
@@ -73,7 +73,7 @@ else {
 @MoYs = map { substr($_,0,9) } @MoY;
 @AMPM = ( "ጠዋት", "ከሰዓት" );
 
-@Dsuf = ("ኛ") x 31;
+@Dsuf = ("ኛ") x 32;
 }
 
 Date::Language::_build_lookups();
diff --git a/lib/Date/Language/Arabic.pm b/lib/Date/Language/Arabic.pm
index 7764845..9375cbb 100644
--- a/lib/Date/Language/Arabic.pm
+++ b/lib/Date/Language/Arabic.pm
@@ -18,7 +18,7 @@ our (@DoW, @DoWs, @MoY, @MoYs, @AMPM, @Dsuf, %MoY, %DoW);
 $MoYs[6] = 'يوليو';
 @AMPM = qw(صباحا مساءا);
 
-@Dsuf = ((qw(er e e e e e e e e e)) x 3, 'er'); #To be amended
+@Dsuf = ((qw(er e e e e e e e e e)) x 3, 'er', 'e'); #To be amended
 
 Date::Language::_build_lookups();
 
diff --git a/lib/Date/Language/Chinese.pm b/lib/Date/Language/Chinese.pm
index e85b4f1..f09ff8a 100644
--- a/lib/Date/Language/Chinese.pm
+++ b/lib/Date/Language/Chinese.pm
@@ -21,7 +21,7 @@ our @DoWs = map { $_ } @DoW;
 our @MoYs = map { $_ } @MoY;
 our @AMPM = qw(上午 下午);
 
-our @Dsuf = ("日") x 31;
+our @Dsuf = ("日") x 32;
 
 our ( %MoY, %DoW );
 Date::Language::_build_lookups();
diff --git a/lib/Date/Language/Chinese_GB.pm b/lib/Date/Language/Chinese_GB.pm
index c6c3916..d7263b3 100644
--- a/lib/Date/Language/Chinese_GB.pm
+++ b/lib/Date/Language/Chinese_GB.pm
@@ -49,7 +49,7 @@ our (@DoW, @DoWs, @MoY, @MoYs, @AMPM, @Dsuf, %MoY, %DoW);
     "\xcf\xc2\xce\xe7",  # 下午
 );
 
-@Dsuf = ("\xc8\xd5") x 31;  # 日
+@Dsuf = ("\xc8\xd5") x 32;  # 日
 
 Date::Language::_build_lookups();
 
diff --git a/lib/Date/Language/Czech.pm b/lib/Date/Language/Czech.pm
index c4b345b..634035f 100644
--- a/lib/Date/Language/Czech.pm
+++ b/lib/Date/Language/Czech.pm
@@ -26,7 +26,7 @@ our @DoW = qw(neděle pondělí úterý středa čtvrtek pátek sobota);
 our @DoWs = qw(Ne Po Út St Čt Pá So);
 
 our @AMPM = qw(dop. odp.);
-our @Dsuf = ('.') x 31;
+our @Dsuf = ('.') x 32;
 
 our ( %MoY, %DoW );
 Date::Language::_build_lookups();
diff --git a/lib/Date/Language/Dutch.pm b/lib/Date/Language/Dutch.pm
index 5c865f9..8512963 100644
--- a/lib/Date/Language/Dutch.pm
+++ b/lib/Date/Language/Dutch.pm
@@ -24,7 +24,7 @@ $MoYs[2] = 'mrt'; # mrt is more common (Frank Maas)
 
 # these aren't normally used...
 @AMPM = qw(VM NM);
-@Dsuf = ('e') x 31;
+@Dsuf = ('e') x 32;
 
 
 Date::Language::_build_lookups();
diff --git a/lib/Date/Language/Finnish.pm b/lib/Date/Language/Finnish.pm
index a3cde18..af6e219 100644
--- a/lib/Date/Language/Finnish.pm
+++ b/lib/Date/Language/Finnish.pm
@@ -26,7 +26,7 @@ our @MoYs = @MoY;
 our @DoWs = @DoW;
 
 # the short form of ordinals
-our @Dsuf = ('.') x 31;
+our @Dsuf = ('.') x 32;
 
 # doesn't look like this is normally used...
 our @AMPM = qw(ap ip);
diff --git a/lib/Date/Language/Greek.pm b/lib/Date/Language/Greek.pm
index cca4db1..b0e1033 100644
--- a/lib/Date/Language/Greek.pm
+++ b/lib/Date/Language/Greek.pm
@@ -75,7 +75,7 @@ our (@DoW, @DoWs, @MoY, @MoYs, @AMPM, @Dsuf, %MoY, %DoW);
 
 @AMPM = ("πμ", "μμ");
 
-@Dsuf = ("η") x 31;
+@Dsuf = ("η") x 32;
 
 Date::Language::_build_lookups();
 
diff --git a/lib/Date/Language/Hungarian.pm b/lib/Date/Language/Hungarian.pm
index 3866a1b..677b852 100644
--- a/lib/Date/Language/Hungarian.pm
+++ b/lib/Date/Language/Hungarian.pm
@@ -64,7 +64,7 @@ our @MoYs = map { substr($_,0,3) } @MoY;
 our @AMPM = qw(DE. DU.);
 
 # There is no 'th or 'nd in Hungarian, just a dot
-our @Dsuf = (".") x 31;
+our @Dsuf = (".") x 32;
 
 our ( %MoY, %DoW );
 Date::Language::_build_lookups();
diff --git a/lib/Date/Language/Occitan.pm b/lib/Date/Language/Occitan.pm
index afa2b81..42c7f67 100644
--- a/lib/Date/Language/Occitan.pm
+++ b/lib/Date/Language/Occitan.pm
@@ -22,7 +22,7 @@ our (@DoW, @DoWs, @MoY, @MoYs, @AMPM, @Dsuf, %MoY, %DoW);
 $MoYs[6] = 'jul';
 @AMPM = qw(AM PM);
 
-@Dsuf = ((qw(er e e e e e e e e e)) x 3, 'er');
+@Dsuf = ((qw(er e e e e e e e e e)) x 3, 'er', 'e');
 
 Date::Language::_build_lookups();
 
diff --git a/lib/Date/Language/Romanian.pm b/lib/Date/Language/Romanian.pm
index 87fa114..ec070f1 100644
--- a/lib/Date/Language/Romanian.pm
+++ b/lib/Date/Language/Romanian.pm
@@ -23,7 +23,7 @@ our (@DoW, @DoWs, @MoY, @MoYs, @AMPM, @Dsuf, %MoY, %DoW);
 
 @AMPM = qw(AM PM);
 
-@Dsuf = ('') x 31;
+@Dsuf = ('') x 32;
 
 
 Date::Language::_build_lookups();
diff --git a/lib/Date/Language/Russian.pm b/lib/Date/Language/Russian.pm
index a893504..93e3317 100644
--- a/lib/Date/Language/Russian.pm
+++ b/lib/Date/Language/Russian.pm
@@ -97,7 +97,7 @@ our (@DoW, @DoWs, @MoY, @MoYs, @MoY2, @DoWs2, @AMPM, @Dsuf, %MoY, %DoW);
     "\xd0\xd0",  # пп
 );
 
-@Dsuf = ('.') x 31;
+@Dsuf = ('.') x 32;
 
 Date::Language::_build_lookups();
 
diff --git a/lib/Date/Language/Russian_cp1251.pm b/lib/Date/Language/Russian_cp1251.pm
index 74a28d6..b8ced1f 100755
--- a/lib/Date/Language/Russian_cp1251.pm
+++ b/lib/Date/Language/Russian_cp1251.pm
@@ -54,7 +54,7 @@ our (@DoW, @DoWs, @MoY, @MoYs, @AMPM, @Dsuf, %MoY, %DoW);
 @MoYs = map { substr($_,0,3) } @MoY;
 @AMPM = qw(AM PM);
 
-@Dsuf = ('e') x 31;
+@Dsuf = ('e') x 32;
 
 Date::Language::_build_lookups();
 
diff --git a/lib/Date/Language/Russian_koi8r.pm b/lib/Date/Language/Russian_koi8r.pm
index 204b90a..a724451 100755
--- a/lib/Date/Language/Russian_koi8r.pm
+++ b/lib/Date/Language/Russian_koi8r.pm
@@ -54,7 +54,7 @@ our (@DoW, @DoWs, @MoY, @MoYs, @AMPM, @Dsuf, %MoY, %DoW);
 @MoYs = map { substr($_,0,3) } @MoY;
 @AMPM = qw(AM PM);
 
-@Dsuf = ('e') x 31;
+@Dsuf = ('e') x 32;
 
 Date::Language::_build_lookups();
 
diff --git a/lib/Date/Language/Spanish.pm b/lib/Date/Language/Spanish.pm
index e57a699..0a00acb 100644
--- a/lib/Date/Language/Spanish.pm
+++ b/lib/Date/Language/Spanish.pm
@@ -21,7 +21,7 @@ our @DoWs = map { substr($_,0,3) } @DoW;
 our @MoYs = map { substr($_,0,3) } @MoY;
 our @AMPM = qw(AM PM);
 
-our @Dsuf = ((qw(ro do ro to to to mo vo no mo)) x 3, 'ro');
+our @Dsuf = ((qw(ro do ro to to to mo vo no mo)) x 3, 'ro', 'do');
 
 our ( %MoY, %DoW );
 Date::Language::_build_lookups();
diff --git a/lib/Date/Language/Swedish.pm b/lib/Date/Language/Swedish.pm
index 67f54d4..ef4708f 100644
--- a/lib/Date/Language/Swedish.pm
+++ b/lib/Date/Language/Swedish.pm
@@ -20,7 +20,7 @@ our @DoW  = map($_ . "dagen", qw(sön mån tis ons tors fre lör));
 our @DoWs = map { substr($_,0,2) } @DoW;
 
 # the ordinals are not typically used in modern times
-our @Dsuf = (('a') x 2, ('e') x 29);
+our @Dsuf = (('a') x 2, ('e') x 30);
 
 our @AMPM =   @{Date::Language::English::AMPM};
 
diff --git a/lib/Date/Language/Tigrinya.pm b/lib/Date/Language/Tigrinya.pm
index 320a632..9fb347e 100644
--- a/lib/Date/Language/Tigrinya.pm
+++ b/lib/Date/Language/Tigrinya.pm
@@ -45,7 +45,7 @@ our (@DoW, @DoWs, @MoY, @MoYs, @AMPM, @Dsuf, %MoY, %DoW);
 "\x{12F5}/\x{1230}"
 );
 
-@Dsuf = ("\x{12ed}") x 31;
+@Dsuf = ("\x{12ed}") x 32;
 
 Date::Language::_build_lookups();
 
diff --git a/lib/Date/Language/TigrinyaEritrean.pm b/lib/Date/Language/TigrinyaEritrean.pm
index 44103b1..8a2d1d6 100644
--- a/lib/Date/Language/TigrinyaEritrean.pm
+++ b/lib/Date/Language/TigrinyaEritrean.pm
@@ -44,7 +44,7 @@ if ( $] >= 5.006 ) {
 "\x{12F5}/\x{1230}"
 );
 
-@Dsuf = ("\x{12ed}") x 31;
+@Dsuf = ("\x{12ed}") x 32;
 }
 else {
 @DoW = (
@@ -77,7 +77,7 @@ else {
 "ድ/ሰ"
 );
 
-@Dsuf = ("ይ") x 31;
+@Dsuf = ("ይ") x 32;
 }
 
 Date::Language::_build_lookups();
diff --git a/lib/Date/Language/TigrinyaEthiopian.pm b/lib/Date/Language/TigrinyaEthiopian.pm
index 600b663..365f50a 100644
--- a/lib/Date/Language/TigrinyaEthiopian.pm
+++ b/lib/Date/Language/TigrinyaEthiopian.pm
@@ -46,7 +46,7 @@ if ( $] >= 5.006 ) {
 "\x{12F5}/\x{1230}"
 );
 
-@Dsuf = ("\x{12ed}") x 31;
+@Dsuf = ("\x{12ed}") x 32;
 }
 else {
 @DoW = (
@@ -79,7 +79,7 @@ else {
 "ድ/ሰ"
 );
 
-@Dsuf = ("ይ") x 31;
+@Dsuf = ("ይ") x 32;
 }
 
 Date::Language::_build_lookups();
diff --git a/lib/Date/Language/Turkish.pm b/lib/Date/Language/Turkish.pm
index 24a8f74..78f9d87 100755
--- a/lib/Date/Language/Turkish.pm
+++ b/lib/Date/Language/Turkish.pm
@@ -41,7 +41,7 @@ our %DsufMAP = (
       31 => 'inci',
 );
 
-our @Dsuf       = map{ $DsufMAP{$_} } sort {$a <=> $b} keys %DsufMAP;
+our @Dsuf       = ((map{ $DsufMAP{$_} } sort {$a <=> $b} keys %DsufMAP), '');
 
 our ( %MoY, %DoW );
 Date::Language::_build_lookups();
diff --git a/t/lang-data.t b/t/lang-data.t
index 54671ed..ba5f5ad 100644
--- a/t/lang-data.t
+++ b/t/lang-data.t
@@ -67,7 +67,7 @@ for my $lang (sort keys %expected) {
     is(scalar @{"${pkg}::MoY"},  12, "$lang: 12 month names");
     is(scalar @{"${pkg}::MoYs"}, 12, "$lang: 12 short month names");
     is(scalar @{"${pkg}::AMPM"}, 2,  "$lang: 2 AM/PM entries");
-    cmp_ok(scalar @{"${pkg}::Dsuf"}, '>=', 31, "$lang: at least 31 day-suffix entries");
+    cmp_ok(scalar @{"${pkg}::Dsuf"}, '>=', 32, "$lang: at least 32 day-suffix entries (indices 0-31)");
 }
 
 # Regression: Austrian October abbreviation must be "Okt" (German), not "Oct" (English)
@@ -116,4 +116,21 @@ for my $lang (sort keys %expected) {
        "Russian: Monday formats as Понедельник");
 }
 
+# Regression: format_o (%o) must produce a suffix for day 31 in all languages.
+# Bug: modules with @Dsuf of only 31 elements (indices 0-30) returned undef for
+# day 31 (index 31), producing a bare "31" instead of "31<suffix>".
+{
+    # Fri Jan 31 00:00:00 2025 UTC — day 31
+    my $day31_time = 1738281600;
+
+    for my $lang (sort keys %expected) {
+        my $obj = Date::Language->new($lang);
+        my $result = $obj->time2str('%o', $day31_time, 'GMT');
+        # Result must start with "31" and must not emit an undef warning.
+        # Languages with empty suffix (e.g. Romanian) produce "31" — that's fine,
+        # but it must be the empty string '', not undef.
+        like($result, qr/^\s*31/, "$lang: format_o day 31 produces output");
+    }
+}
+
 done_testing;