Clarify Gitea/Crowdin locale behaviors, add tests for LocaleStore, fix some strings with semicolons (#23819)

Follow #23633 and #23240

Close #23814

Now we almost have a complete test set for Gitea's LocalStore.

This PR is still a quick fix for the legacy locale system (see the
TODOs), to resolve the problems fundamentally, it needs more work in the
future.

3 files changed, 62 insertions, 15 deletions

diff --git a/build/update-locales.sh b/build/update-locales.sh
index 596ddfec03..6f9ee334be 100755
--- a/build/update-locales.sh
+++ b/build/update-locales.sh
@@ -17,17 +17,10 @@ fi
 
 mv ./options/locale/locale_en-US.ini ./options/
 
-# the "ini" library for locale has many quirks
-#  * `a="xx"` gets `xx` (no quote)
-#  * `a=x\"y` gets `x\"y` (no unescaping)
-#  * `a="x\"y"` gets `"x\"y"` (no unescaping, the quotes are still there)
-#  * `a='x\"y'` gets `x\"y` (no unescaping, no quote)
-#  * `a="foo` gets `"foo` (although the quote is not closed)
-#  * 'a=`foo`' works like single-quote
-# crowdin needs the strings to be quoted correctly and doesn't like incomplete quotes
-# crowdin always outputs quoted strings if there are quotes in the strings.
-
-# this script helps to unquote the crowdin outputs for the quirky ini library
+# the "ini" library for locale has many quirks, its behavior is different from Crowdin.
+# see i18n_test.go for more details
+
+# this script helps to unquote the Crowdin outputs for the quirky ini library
 # * find all `key="...\"..."` lines
 # * remove the leading quote
 # * remove the trailing quote
diff --git a/modules/translation/i18n/i18n_test.go b/modules/translation/i18n/i18n_test.go
index 76a91522ba..085d03811f 100644
--- a/modules/translation/i18n/i18n_test.go
+++ b/modules/translation/i18n/i18n_test.go
@@ -4,6 +4,7 @@
 package i18n
 
 import (
+	"strings"
 	"testing"
 
 	"github.com/stretchr/testify/assert"
@@ -75,3 +76,56 @@ c=22
 	assert.Equal(t, "21", ls.Tr("lang1", "b"))
 	assert.Equal(t, "22", ls.Tr("lang1", "c"))
 }
+
+func TestLocaleStoreQuirks(t *testing.T) {
+	const nl = "\n"
+	q := func(q1, s string, q2 ...string) string {
+		return q1 + s + strings.Join(q2, "")
+	}
+	testDataList := []struct {
+		in   string
+		out  string
+		hint string
+	}{
+		{` xx`, `xx`, "simple, no quote"},
+		{`" xx"`, ` xx`, "simple, double-quote"},
+		{`' xx'`, ` xx`, "simple, single-quote"},
+		{"` xx`", ` xx`, "simple, back-quote"},
+
+		{`x\"y`, `x\"y`, "no unescape, simple"},
+		{q(`"`, `x\"y`, `"`), `"x\"y"`, "unescape, double-quote"},
+		{q(`'`, `x\"y`, `'`), `x\"y`, "no unescape, single-quote"},
+		{q("`", `x\"y`, "`"), `x\"y`, "no unescape, back-quote"},
+
+		{q(`"`, `x\"y`) + nl + "b=", `"x\"y`, "half open, double-quote"},
+		{q(`'`, `x\"y`) + nl + "b=", `'x\"y`, "half open, single-quote"},
+		{q("`", `x\"y`) + nl + "b=`", `x\"y` + nl + "b=", "half open, back-quote, multi-line"},
+
+		{`x ; y`, `x ; y`, "inline comment (;)"},
+		{`x # y`, `x # y`, "inline comment (#)"},
+		{`x \; y`, `x ; y`, `inline comment (\;)`},
+		{`x \# y`, `x # y`, `inline comment (\#)`},
+	}
+
+	for _, testData := range testDataList {
+		ls := NewLocaleStore()
+		err := ls.AddLocaleByIni("lang1", "Lang1", []byte("a="+testData.in), nil)
+		assert.NoError(t, err, testData.hint)
+		assert.Equal(t, testData.out, ls.Tr("lang1", "a"), testData.hint)
+		assert.NoError(t, ls.Close())
+	}
+
+	// TODO: Crowdin needs the strings to be quoted correctly and doesn't like incomplete quotes
+	//       and Crowdin always outputs quoted strings if there are quotes in the strings.
+	//       So, Gitea's `key="quoted" unquoted` content shouldn't be used on Crowdin directly,
+	//       it should be converted to `key="\"quoted\" unquoted"` first.
+	// TODO: We can not use UnescapeValueDoubleQuotes=true, because there are a lot of back-quotes in en-US.ini,
+	//       then Crowdin will output:
+	//       > key = "`x \" y`"
+	//       Then Gitea will read a string with back-quotes, which is incorrect.
+	// TODO: Crowdin might generate multi-line strings, quoted by double-quote, it's not supported by LocaleStore
+	//       LocaleStore uses back-quote for multi-line strings, it's not supported by Crowdin.
+	// TODO: Crowdin doesn't support back-quote as string quoter, it mainly uses double-quote
+	//       so, the following line will be parsed as: value="`first", comment="second`" on Crowdin
+	//       > a = `first; second`
+}
diff --git a/options/locale/locale_en-US.ini b/options/locale/locale_en-US.ini
index 0d5b2c9a44..347f5e4312 100644
--- a/options/locale/locale_en-US.ini
+++ b/options/locale/locale_en-US.ini
@@ -2140,10 +2140,10 @@ settings.dismiss_stale_approvals_desc = When new commits that change the content
 settings.require_signed_commits = Require Signed Commits
 settings.require_signed_commits_desc = Reject pushes to this branch if they are unsigned or unverifiable.
 settings.protect_branch_name_pattern = Protected Branch Name Pattern
-settings.protect_protected_file_patterns = `Protected file patterns (separated using semicolon ';'):`
-settings.protect_protected_file_patterns_desc = `Protected files are not allowed to be changed directly even if user has rights to add, edit, or delete files in this branch. Multiple patterns can be separated using semicolon (';'). See <a href="https://pkg.go.dev/github.com/gobwas/glob#Compile">github.com/gobwas/glob</a> documentation for pattern syntax. Examples: <code>.drone.yml</code>, <code>/docs/**/*.txt</code>.`
-settings.protect_unprotected_file_patterns = `Unprotected file patterns (separated using semicolon ';'):`
-settings.protect_unprotected_file_patterns_desc = `Unprotected files that are allowed to be changed directly if user has write access, bypassing push restriction. Multiple patterns can be separated using semicolon (';'). See <a href="https://pkg.go.dev/github.com/gobwas/glob#Compile">github.com/gobwas/glob</a> documentation for pattern syntax. Examples: <code>.drone.yml</code>, <code>/docs/**/*.txt</code>.`
+settings.protect_protected_file_patterns = "Protected file patterns (separated using semicolon ';'):"
+settings.protect_protected_file_patterns_desc = "Protected files are not allowed to be changed directly even if user has rights to add, edit, or delete files in this branch. Multiple patterns can be separated using semicolon (';'). See <a href='https://pkg.go.dev/github.com/gobwas/glob#Compile'>github.com/gobwas/glob</a> documentation for pattern syntax. Examples: <code>.drone.yml</code>, <code>/docs/**/*.txt</code>."
+settings.protect_unprotected_file_patterns = "Unprotected file patterns (separated using semicolon ';'):"
+settings.protect_unprotected_file_patterns_desc = "Unprotected files that are allowed to be changed directly if user has write access, bypassing push restriction. Multiple patterns can be separated using semicolon (';'). See <a href='https://pkg.go.dev/github.com/gobwas/glob#Compile'>github.com/gobwas/glob</a> documentation for pattern syntax. Examples: <code>.drone.yml</code>, <code>/docs/**/*.txt</code>."
 settings.add_protected_branch = Enable protection
 settings.delete_protected_branch = Disable protection
 settings.update_protect_branch_success = Branch protection for rule '%s' has been updated.