Fixes go-gitea#14422: Don't use sub-path twice for manifest

modules/setting/setting.go

@@ -104,6 +104,7 @@ var (
 	GracefulHammerTime   time.Duration
 	StartupTimeout       time.Duration
 	StaticURLPrefix      string
+	StaticURLPrefixManifest      string
 	AbsoluteAssetURL     string
 
 	SSH = struct {
@@ -606,6 +607,11 @@ func NewContext() {
 	// Suburl should start with '/' and end without '/', such as '/{subpath}'.
 	// This value is empty if site does not have sub-url.
 	AppSubURL = strings.TrimSuffix(appURL.Path, "/")
+	// FIXME: Why does the content of 'StaticURLPrefixManifest' depend on the ordering of
+	//   the next two lines?
+	// Manifest on top: ""
+	// Manifest below:  "/gitea"
+	StaticURLPrefixManifest = strings.TrimSuffix(sec.Key("STATIC_URL_PREFIX").MustString(""), "/")
 	StaticURLPrefix = strings.TrimSuffix(sec.Key("STATIC_URL_PREFIX").MustString(AppSubURL), "/")
 	AppSubURLDepth = strings.Count(AppSubURL, "/")
 	// Check if Domain differs from AppURL domain than update it to AppURL's domain
@@ -614,7 +620,7 @@ func NewContext() {
 		Domain = urlHostname
 	}
 
-	AbsoluteAssetURL = MakeAbsoluteAssetURL(AppURL, StaticURLPrefix)
+	AbsoluteAssetURL = MakeAbsoluteAssetURL(AppURL, StaticURLPrefixManifest)
 
 	manifestBytes := MakeManifestData(AppName, AppURL, AbsoluteAssetURL)
 	ManifestData = `application/json;base64,` + base64.StdEncoding.EncodeToString(manifestBytes)