[damned-lies] Catch action collision errors

[Claude Paroz <claudep src gnome org>]

commit 1b4cbcfb32a52d9701eee85ef5b266739e81cf8a
Author: Claude Paroz <claude 2xlibre net>
Date:   Wed Aug 26 08:53:57 2009 +0200

    Catch action collision errors
    
    When someone reloads an already submitted action, or that someone else
    posted an action in-between, the current action may be unvalid.
    Catch it and display also the error on the top of the template,
    because if there is a long list of action, the user may miss the
    error message.

 templates/vertimus/vertimus_detail.html |    4 ++++
 vertimus/forms.py                       |    5 ++++-
 2 files changed, 8 insertions(+), 1 deletions(-)
---
diff --git a/templates/vertimus/vertimus_detail.html b/templates/vertimus/vertimus_detail.html
index b6f49f2..e6759e2 100644
--- a/templates/vertimus/vertimus_detail.html
+++ b/templates/vertimus/vertimus_detail.html
@@ -17,6 +17,10 @@ $(document).ready(function() {
 
 {% block content %}
 <div class="mainpage">
+{% if action_form.non_field_errors %}
+  {{ action_form.non_field_errors }}
+{% endif %}
+
 {% with branch.releases.all as releases %}
 <div class="release_link">
 {% if releases %}
diff --git a/vertimus/forms.py b/vertimus/forms.py
index d147500..d102940 100644
--- a/vertimus/forms.py
+++ b/vertimus/forms.py
@@ -66,7 +66,10 @@ class ActionForm(forms.Form):
 
     def clean(self):
         cleaned_data = self.cleaned_data
-        action = ActionAbstract.new_by_name(cleaned_data.get('action'))
+        action_code = cleaned_data.get('action')
+        if action_code is None:
+            raise forms.ValidationError(_("Unvalid action. Someone probably posted another action just before you."))
+        action = ActionAbstract.new_by_name(action_code)
         comment = cleaned_data.get('comment')
         file = cleaned_data.get('file')