Quick fix for the signin page, we should consider moving it over to AJAX though.

endpoints/web.py

@@ -1,6 +1,7 @@
 import logging
 
-from flask import abort, send_file, redirect, request, url_for
+from flask import (abort, send_file, redirect, request, url_for,
+                   render_template)
 from flask.ext.login import login_user, UserMixin, login_required, logout_user
 from flask.ext.principal import identity_changed, Identity, AnonymousIdentity
 
@@ -42,6 +43,11 @@ def common_login(db_user):
   identity_changed.send(app, identity=Identity(db_user.username, 'username'))
 
 
+@app.route('/signin', methods=['GET'])
+def render_signin_page():
+  return render_template('signin.html')
+
+
 @app.route('/signin', methods=['POST'])
 def signin():
   username = request.form['username']
@@ -54,7 +60,10 @@ def signin():
 
     return redirect(request.args.get('next') or url_for('index'))
 
-  abort(403)
+  else:
+    return render_template('signin.html',
+                           username=username,
+                           error='Invalid username or password.')
 
 
 @app.route('/confirm', methods=['GET'])
@@ -72,11 +81,6 @@ def password_reset():
   pass
 
 
-@app.route('/signin', methods=['GET'])
-def render_signin_page():
-  return send_file('templates/signin.html')
-
-
 @app.route("/signout")
 @login_required
 def logout():