From 453cc2258191d391ee8a1584fe2b6e78e7e09eed Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Bj=C3=B8rn=20Erik=20Pedersen?=
 <bjorn.erik.pedersen@gmail.com>
Date: Sat, 24 Apr 2021 17:23:32 +0200
Subject: [PATCH] Fix handling of artificial languages

This works around what seems to be an upstream by implementing a simplified tag matcher for artificual languages.

Fixes #252
---
 v2/go.mod              |  2 --
 v2/i18n/bundle.go      | 52 ++++++++++++++++++++++++++++++++++++++++--
 v2/i18n/bundle_test.go |  2 +-
 v2/i18n/localizer.go   |  1 -
 4 files changed, 51 insertions(+), 6 deletions(-)

diff --git a/v2/go.mod b/v2/go.mod
index ce404c69..447a6857 100644
--- a/v2/go.mod
+++ b/v2/go.mod
@@ -7,5 +7,3 @@ require (
 	golang.org/x/text v0.3.3
 	gopkg.in/yaml.v2 v2.3.0
 )
-
-replace golang.org/x/text  => /Users/bep/dev/go/dump/text
diff --git a/v2/i18n/bundle.go b/v2/i18n/bundle.go
index 513c127d..077f29fc 100644
--- a/v2/i18n/bundle.go
+++ b/v2/i18n/bundle.go
@@ -26,9 +26,57 @@ type Bundle struct {
 	matcher          language.Matcher
 }
 
+// The matcher in x/text/language does not handle artificial languages,
+// see https://github.com/golang/go/issues/45749
+// This is a simplified matcher thatdelegates to the x/text/language matcher for
+// the harder cases.
+type matcher struct {
+	tags           []language.Tag
+	defaultMatcher language.Matcher
+}
+
+func newMatcher(tags []language.Tag) language.Matcher {
+	var hasArt bool
+	for _, tag := range tags {
+		base, _ := tag.Base()
+		hasArt = base == artTagBase
+		if hasArt {
+			break
+		}
+	}
+
+	if !hasArt {
+		return language.NewMatcher(tags)
+	}
+
+	return matcher{
+		tags:           tags,
+		defaultMatcher: language.NewMatcher(tags),
+	}
+}
+
+func (m matcher) Match(t ...language.Tag) (language.Tag, int, language.Confidence) {
+	if len(t) == 1 {
+		candidate := t[0]
+		base, _ := candidate.Base()
+		if base == artTagBase {
+			for i, tag := range m.tags {
+				if tag == candidate {
+					return candidate, i, language.Exact
+				}
+			}
+		}
+	}
+
+	return m.defaultMatcher.Match(t...)
+}
+
 // artTag is the language tag used for artificial languages
 // https://en.wikipedia.org/wiki/Codes_for_constructed_languages
-var artTag = language.MustParse("art")
+var (
+	artTag        = language.MustParse("art")
+	artTagBase, _ = artTag.Base()
+)
 
 // NewBundle returns a bundle with a default language and a default set of plural rules.
 func NewBundle(defaultLanguage language.Tag) *Bundle {
@@ -126,7 +174,7 @@ func (b *Bundle) addTag(tag language.Tag) {
 		}
 	}
 	b.tags = append(b.tags, tag)
-	b.matcher = language.NewMatcher(b.tags)
+	b.matcher = newMatcher(b.tags)
 }
 
 // LanguageTags returns the list of language tags
diff --git a/v2/i18n/bundle_test.go b/v2/i18n/bundle_test.go
index af5dded7..9afb8514 100644
--- a/v2/i18n/bundle_test.go
+++ b/v2/i18n/bundle_test.go
@@ -101,7 +101,7 @@ hello = "`+expected+`"
 func TestPseudoLanguages(t *testing.T) {
 	bundle := NewBundle(language.English)
 	bundle.RegisterUnmarshalFunc("toml", toml.Unmarshal)
-	expected := "a3"
+	expected := "a2"
 	bundle.MustParseMessageFileBytes([]byte(`
 hello = "a1"
 `), "art-x-a1.toml")
diff --git a/v2/i18n/localizer.go b/v2/i18n/localizer.go
index 9ff65163..17261e2e 100644
--- a/v2/i18n/localizer.go
+++ b/v2/i18n/localizer.go
@@ -171,7 +171,6 @@ func (l *Localizer) LocalizeWithTag(lc *LocalizeConfig) (string, language.Tag, e
 
 func (l *Localizer) getMessageTemplate(id string, defaultMessage *Message) (language.Tag, *MessageTemplate, error) {
 	_, i, _ := l.bundle.matcher.Match(l.tags...)
-	fmt.Println("I", l.tags, l.bundle.tags, i)
 	tag := l.bundle.tags[i]
 	mt := l.bundle.getMessageTemplate(tag, id)
 	if mt != nil {