Support localized README (#20508)

* Support localized README

* Slightly simplify getting the readme file and add some tests. Ensure that i18n also
works for docs/ etc.

Signed-off-by: Andrew Thornton <art27@cantab.net>

* Update modules/markup/renderer.go

* Update modules/markup/renderer.go

* Update modules/markup/renderer.go

Co-authored-by: Andrew Thornton <art27@cantab.net>

1 files changed, 26 insertions, 7 deletions

diff --git a/modules/markup/renderer.go b/modules/markup/renderer.go
index e88fa31187..9278d4c65d 100644
--- a/modules/markup/renderer.go
+++ b/modules/markup/renderer.go
@@ -310,14 +310,9 @@ func IsMarkupFile(name, markup string) bool {
 }
 
 // IsReadmeFile reports whether name looks like a README file
-// based on its name. If an extension is provided, it will strictly
-// match that extension.
-// Note that the '.' should be provided in ext, e.g ".md"
-func IsReadmeFile(name string, ext ...string) bool {
+// based on its name.
+func IsReadmeFile(name string) bool {
 	name = strings.ToLower(name)
-	if len(ext) > 0 {
-		return name == "readme"+ext[0]
-	}
 	if len(name) < 6 {
 		return false
 	} else if len(name) == 6 {
@@ -325,3 +320,27 @@ func IsReadmeFile(name string, ext ...string) bool {
 	}
 	return name[:7] == "readme."
 }
+
+// IsReadmeFileExtension reports whether name looks like a README file
+// based on its name. It will look through the provided extensions and check if the file matches
+// one of the extensions and provide the index in the extension list.
+// If the filename is `readme.` with an unmatched extension it will match with the index equaling
+// the length of the provided extension list.
+// Note that the '.' should be provided in ext, e.g ".md"
+func IsReadmeFileExtension(name string, ext ...string) (int, bool) {
+	if len(name) < 6 || name[:6] != "readme" {
+		return 0, false
+	}
+
+	for i, extension := range ext {
+		if name[6:] == extension {
+			return i, true
+		}
+	}
+
+	if name[6] == '.' {
+		return len(ext), true
+	}
+
+	return 0, false
+}