Always include Promise polyfill for legacy browsers

It is now used by our general code and not just by the conversion
routines, so we need to make sure it is always included for the
old browsers.

kasmweb/utils/use_require.js

@@ -30,10 +30,13 @@ const no_copy_files = new Set([
     // skip these -- they don't belong in the processed application
     path.join(paths.vendor, 'sinon.js'),
     path.join(paths.vendor, 'browser-es-module-loader'),
-    path.join(paths.vendor, 'promise.js'),
     path.join(paths.app, 'images', 'icons', 'Makefile'),
 ]);
 
+const only_legacy_scripts = new Set([
+    path.join(paths.vendor, 'promise.js'),
+]);
+
 const no_transform_files = new Set([
     // don't transform this -- we want it imported as-is to properly catch loading errors
     path.join(paths.app, 'error-handler.js'),
@@ -174,6 +177,7 @@ function make_lib_files(import_format, source_maps, with_app_dir, only_legacy) {
     const helper = helpers[import_format];
 
     const outFiles = [];
+    const legacyFiles = [];
 
     const handleDir = (js_only, vendor_rewrite, in_path_base, filename) => Promise.resolve()
         .then(() => {
@@ -196,6 +200,15 @@ function make_lib_files(import_format, source_maps, with_app_dir, only_legacy) {
                     });
             }
 
+            if (only_legacy_scripts.has(filename)) {
+                legacyFiles.push(legacy_path);
+                return ensureDir(path.dirname(legacy_path))
+                    .then(() => {
+                        console.log(`Writing ${legacy_path}`);
+                        return copy(filename, legacy_path);
+                    });
+            }
+
             return Promise.resolve()
                 .then(() => {
                     if (only_legacy) {
@@ -243,10 +256,6 @@ function make_lib_files(import_format, source_maps, with_app_dir, only_legacy) {
                 });
         });
 
-    if (with_app_dir && helper && helper.noCopyOverride) {
-        helper.noCopyOverride(paths, no_copy_files);
-    }
-
     Promise.resolve()
         .then(() => {
             const handler = handleDir.bind(null, true, false, in_path || paths.main);
@@ -275,8 +284,16 @@ function make_lib_files(import_format, source_maps, with_app_dir, only_legacy) {
             console.log(`Writing ${out_app_path}`);
             return helper.appWriter(out_path_base, legacy_path_base, out_app_path)
                 .then((extra_scripts) => {
-                    const rel_app_path = path.relative(out_path_base, out_app_path);
-                    const legacy_scripts = extra_scripts.concat([rel_app_path]);
+                    let legacy_scripts = extra_scripts;
+
+                    legacyFiles.forEach((file) => {
+                        let rel_file_path = path.relative(out_path_base, file);
+                        legacy_scripts.push(rel_file_path);
+                    });
+
+                    let rel_app_path = path.relative(out_path_base, out_app_path);
+                    legacy_scripts.push(rel_app_path);
+
                     transform_html(legacy_scripts, only_legacy);
                 })
                 .then(() => {

kasmweb/utils/use_require_helpers.js

@@ -31,7 +31,6 @@ module.exports = {
                     return [ require_path ];
                 });
         },
-        noCopyOverride: () => {},
     },
     'commonjs': {
         optionsOverride: (opts) => {
@@ -45,7 +44,6 @@ module.exports = {
                 .then(buf => writeFile(out_path, buf))
                 .then(() => []);
         },
-        noCopyOverride: () => {},
         removeModules: true,
     },
     'systemjs': {
@@ -55,17 +53,11 @@ module.exports = {
             return writeFile(out_path, `SystemJS.import("${ui_path}");`)
                 .then(() => {
                     console.log(`Please place SystemJS in ${path.join(script_base_path, 'system-production.js')}`);
-                // FIXME: Should probably be in the legacy directory
-                    const promise_path = path.relative(base_out_path,
-                                                       path.join(base_out_path, 'vendor', 'promise.js'));
                     const systemjs_path = path.relative(base_out_path,
                                                         path.join(script_base_path, 'system-production.js'));
-                    return [ promise_path, systemjs_path ];
+                    return [ systemjs_path ];
                 });
         },
-        noCopyOverride: (paths, no_copy_files) => {
-            no_copy_files.delete(path.join(paths.vendor, 'promise.js'));
-        },
     },
     'umd': {
         optionsOverride: (opts) => {