- 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/api/atom_api_web_contents.cc
v8::Isolate* isolate, content::WebContents* web_contents) {
  
  auto existing = TrackableObject::FromWrappedClass(isolate, web_contents);
  if (existing)
    return mate::CreateHandle(isolate, static_cast<WebContents*>(existing));
  
  return mate::CreateHandle(isolate, new WebContents(isolate, web_contents));
}
mate::Handle<WebContents> WebContents::Create(
    v8::Isolate* isolate, const mate::Dictionary& options) {
  return mate::CreateHandle(isolate, new WebContents(isolate, options));
}
}  
}  
namespace {
using atom::api::WebContents;
void Initialize(v8::Local<v8::Object> exports, v8::Local<v8::Value> unused,
                v8::Local<v8::Context> context, void* priv) {
  v8::Isolate* isolate = context->GetIsolate();
  mate::Dictionary dict(isolate, exports);
  dict.Set("WebContents", WebContents::GetConstructor(isolate)->GetFunction());
  dict.SetMethod("create", &WebContents::Create);
  dict.SetMethod("fromId", &mate::TrackableObject<WebContents>::FromWeakMapID);
  dict.SetMethod("getAllWebContents",
                 &mate::TrackableObject<WebContents>::GetAll);
}
}  
NODE_MODULE_CONTEXT_AWARE_BUILTIN(atom_browser_web_contents, Initialize)