- Electron version: 1.3.5
- Operating system: macOS/Windows

Alt-clicking a link is a default shortcut for downloading a file without a save prompt, and we make use of it in our app. But for links that end in a trailing slash, the resulting filename isn't consistent with the default file name in the save prompt.

The save prompt constructs a name from the word "download" and the extension for the mime type of the file, but the prompt-less savepath is just the domain name of the link. This leads to unusable files (e.g. with a .com file extension) being saved to the filesystem.

Here's my current workaround, but given the prompt does get a useful path, and Chrome behaves correctly, I imagine this might be straightforward to fix if you know where to look:

``` javascript
const mime = require('mime-types');
const _ = require('lodash');
const path = require('path');
const unusedFilename = require('unused-filename');

win.webContents.session.on('will-download', function (e, item, webContents) {
  if (item.getSavePath() && _.last(item.getURL()) === '/') {
      var savePath = unusedFilename.sync(path.format({
        dir: path.dirname(item.getSavePath()),
        name: 'download',
        ext: '.' + mime.extension(item.getMimeType())
      }));
      item.setSavePath(savePath);
    }
});
```

atom/browser/atom_download_manager_delegate.cc
base::FilePath default_download_path = browser_context->prefs()->GetFilePath(
      prefs::kDownloadDefaultDirectory);
  CreateDownloadPathCallback download_path_callback =
      base::Bind(&AtomDownloadManagerDelegate::OnDownloadPathGenerated,
                 weak_ptr_factory_.GetWeakPtr(),
                 download->GetId(), callback);
  content::BrowserThread::PostTask(
      content::BrowserThread::FILE, FROM_HERE,
      base::Bind(&AtomDownloadManagerDelegate::CreateDownloadPath,
                 weak_ptr_factory_.GetWeakPtr(),
                 download->GetURL(),
                 download->GetContentDisposition(),
                 download->GetSuggestedFilename(),
                 download->GetMimeType(),
                 default_download_path,
                 download_path_callback));
  return true;
}
bool AtomDownloadManagerDelegate::ShouldOpenDownload(
    content::DownloadItem* download,
    const content::DownloadOpenDelayedCallback& callback) {
  return true;
}
void AtomDownloadManagerDelegate::GetNextId(
    const content::DownloadIdCallback& callback) {
  static uint32_t next_id = content::DownloadItem::kInvalidId + 1;
  callback.Run(next_id++);
}
}