Fix plural forms for locales like Brazilian Portuguese

lib/gettext.js

@@ -301,7 +301,10 @@ Gettext.prototype.dnpgettext = function(domain, msgctxt, msgid, msgidPlural, cou
 
     if (translation) {
         if (typeof count === 'number') {
-            var pluralsFunc = plurals[Gettext.getLanguageCode(this.locale)].pluralsFunc;
+            // Prefer a locale-specific plural form (e.g. pt_BR) before the language (pt)
+            var localeKey = this.locale.toLowerCase().replace(/-/g, '_');
+            var pluralForms = plurals[localeKey] || plurals[Gettext.getLanguageCode(this.locale)];
+            var pluralsFunc = pluralForms.pluralsFunc;
             index = pluralsFunc(count);
             if (typeof index === 'boolean') {
                 index = index ? 1 : 0;

lib/plurals.js

@@ -1525,6 +1525,21 @@ module.exports = {
             return (n !== 1);
         }
     },
+    pt_br: {
+        name: 'Brazilian Portuguese',
+        examples: [{
+            plural: 0,
+            sample: 1
+        }, {
+            plural: 1,
+            sample: 2
+        }],
+        nplurals: 2,
+        pluralsText: 'nplurals = 2; plural = (n > 1)',
+        pluralsFunc: function(n) {
+            return (n > 1);
+        }
+    },
     rm: {
         name: 'Romansh',
         examples: [{

test/gettext-test.js

@@ -218,6 +218,59 @@ describe('Gettext', function() {
         });
     });
 
+    describe('Locale-specific plural forms', function() {
+        var catalog;
+
+        beforeEach(function() {
+            catalog = {
+                charset: 'utf-8',
+                headers: {},
+                translations: {
+                    '': {
+                        apple: {
+                            msgid: 'apple',
+                            msgid_plural: 'apples',
+                            msgstr: ['singular', 'plural']
+                        }
+                    }
+                }
+            };
+        });
+
+        it('should use n > 1 for Brazilian Portuguese (pt_BR)', function() {
+            gt.addTranslations('pt_BR', 'messages', catalog);
+            gt.setLocale('pt_BR');
+
+            expect(gt.ngettext('apple', 'apples', 0)).to.equal('singular');
+            expect(gt.ngettext('apple', 'apples', 1)).to.equal('singular');
+            expect(gt.ngettext('apple', 'apples', 2)).to.equal('plural');
+        });
+
+        it('should treat hyphenated pt-BR the same as pt_BR', function() {
+            gt.addTranslations('pt-BR', 'messages', catalog);
+            gt.setLocale('pt-BR');
+
+            expect(gt.ngettext('apple', 'apples', 0)).to.equal('singular');
+        });
+
+        it('should keep Portuguese (pt) as n !== 1', function() {
+            gt.addTranslations('pt', 'messages', catalog);
+            gt.setLocale('pt');
+
+            expect(gt.ngettext('apple', 'apples', 0)).to.equal('plural');
+            expect(gt.ngettext('apple', 'apples', 1)).to.equal('singular');
+            expect(gt.ngettext('apple', 'apples', 2)).to.equal('plural');
+        });
+
+        it('should fall back to the language-level plural form when the locale is not listed', function() {
+            gt.addTranslations('et-EE', 'messages', catalog);
+            gt.setLocale('et-EE');
+
+            expect(gt.ngettext('apple', 'apples', 0)).to.equal('plural');
+            expect(gt.ngettext('apple', 'apples', 1)).to.equal('singular');
+        });
+    });
+
     describe('Unresolvable transaltions', function() {
         beforeEach(function() {
             gt.addTranslations('et-EE', 'messages', jsonFile);