Don't choke when publishing a package with an empty submodule (#1710)

Closes #1679

Author: nex3

lib/src/package.dart

@@ -258,7 +258,12 @@ class Package {
       // Git prints files relative to [beneath], but we want them relative to
       // the pub's working directory. It also prints forward slashes on Windows
       // which we normalize away for easier testing.
-      files = files.map((file) {
+      //
+      // Git lists empty directories as "./", which we skip so we don't keep
+      // trying to recurse into the same directory. Normally git doesn't allow
+      // totally empty directories, but a submodule that's not checked out
+      // behaves like one.
+      files = files.where((file) => file != './').map((file) {
         if (Platform.operatingSystem != 'windows') return "$beneath/$file";
         return "$beneath\\${file.replaceAll("/", "\\")}";
       }).expand((file) {

test/lish/archives_and_uploads_a_package_test.dart

@@ -4,11 +4,13 @@
 
 import 'dart:convert';
 
+import 'package:path/path.dart' as p;
 import 'package:shelf/shelf.dart' as shelf;
 import 'package:shelf_test_handler/shelf_test_handler.dart';
 import 'package:test/test.dart';
 
 import 'package:pub/src/exit_codes.dart' as exit_codes;
+import 'package:pub/src/io.dart';
 
 import '../descriptor.dart' as d;
 import '../test_pub.dart';
@@ -37,6 +39,40 @@ main() {
     await pub.shouldExit(exit_codes.SUCCESS);
   });
 
+  // This is a regression test for #1679. We create a submodule that's not
+  // checked out to ensure that file listing doesn't choke on the empty
+  // directory.
+  test('with an empty Git submodule', () async {
+    await d.git('empty').create();
+
+    var repo = d.git(appPath);
+    await repo.create();
+
+    await repo.runGit(['submodule', 'add', '../empty', 'empty']);
+    await repo.commit();
+
+    deleteEntry(p.join(d.sandbox, appPath, 'empty'));
+    await d.dir(p.join(appPath, 'empty')).create();
+
+    var server = await ShelfTestServer.create();
+    await d.credentialsFile(server, 'access token').create();
+    var pub = await startPublish(server);
+
+    await confirmPublish(pub);
+    handleUploadForm(server);
+    handleUpload(server);
+
+    server.handler.expect('GET', '/create', (request) {
+      return new shelf.Response.ok(JSON.encode({
+        'success': {'message': 'Package test_pkg 1.0.0 uploaded!'}
+      }));
+    });
+
+    expect(pub.stdout, emits(startsWith('Uploading...')));
+    expect(pub.stdout, emits('Package test_pkg 1.0.0 uploaded!'));
+    await pub.shouldExit(exit_codes.SUCCESS);
+  });
+
   // TODO(nweiz): Once a multipart/form-data parser in Dart exists, we should
   // test that "pub lish" chooses the correct files to publish.
 }