Prevent use of double sub-path and incorrect asset path in manifest (#14827)

MakeAbsoluteAssetURL should just url join the static url prefix on to appurl
if it is not an absolute path - this is because StaticURLPrefix is an absolute
prefix not a relative prefix to the app sub url.

Fix #14422

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

modules/setting/setting.go

@@ -1090,7 +1090,7 @@ func MakeAbsoluteAssetURL(appURL string, staticURLPrefix string) string {
 		}
 
 		// StaticURLPrefix is just a path
-		return strings.TrimSuffix(appURL, "/") + strings.TrimSuffix(staticURLPrefix, "/")
+		return util.URLJoin(appURL, strings.TrimSuffix(staticURLPrefix, "/"))
 	}
 
 	return strings.TrimSuffix(staticURLPrefix, "/")

modules/setting/setting_test.go

@@ -18,9 +18,12 @@ func TestMakeAbsoluteAssetURL(t *testing.T) {
 	assert.Equal(t, "https://localhost:1234/foo", MakeAbsoluteAssetURL("https://localhost:1234", "/foo"))
 	assert.Equal(t, "https://localhost:1234/foo", MakeAbsoluteAssetURL("https://localhost:1234/", "/foo"))
 	assert.Equal(t, "https://localhost:1234/foo", MakeAbsoluteAssetURL("https://localhost:1234/", "/foo/"))
-	assert.Equal(t, "https://localhost:1234/foo/bar", MakeAbsoluteAssetURL("https://localhost:1234/foo", "/bar"))
-	assert.Equal(t, "https://localhost:1234/foo/bar", MakeAbsoluteAssetURL("https://localhost:1234/foo/", "/bar"))
-	assert.Equal(t, "https://localhost:1234/foo/bar", MakeAbsoluteAssetURL("https://localhost:1234/foo/", "/bar/"))
+	assert.Equal(t, "https://localhost:1234/foo", MakeAbsoluteAssetURL("https://localhost:1234/foo", "/foo"))
+	assert.Equal(t, "https://localhost:1234/foo", MakeAbsoluteAssetURL("https://localhost:1234/foo/", "/foo"))
+	assert.Equal(t, "https://localhost:1234/foo", MakeAbsoluteAssetURL("https://localhost:1234/foo/", "/foo/"))
+	assert.Equal(t, "https://localhost:1234/bar", MakeAbsoluteAssetURL("https://localhost:1234/foo", "/bar"))
+	assert.Equal(t, "https://localhost:1234/bar", MakeAbsoluteAssetURL("https://localhost:1234/foo/", "/bar"))
+	assert.Equal(t, "https://localhost:1234/bar", MakeAbsoluteAssetURL("https://localhost:1234/foo/", "/bar/"))
 }
 
 func TestMakeManifestData(t *testing.T) {