Move the 'should we offer the copy_subpages checkbox or not' logic into CopyForm itself. This also allows us to move the help text into the actual help_text property, which fixes the dodgy spacing on the form field

wagtail/wagtailadmin/forms.py

@@ -87,7 +87,12 @@ class CopyForm(forms.Form):
         self.fields['new_title'] = forms.CharField(initial=self.page.title)
         self.fields['new_slug'] = forms.SlugField(initial=self.page.slug)
 
-    copy_subpages = forms.BooleanField(required=False, initial=True)
+        pages_to_copy_count = self.page.get_descendants(inclusive=True).count()
+        if pages_to_copy_count > 1:
+            subpage_count = pages_to_copy_count - 1
+            self.fields['copy_subpages'] = forms.BooleanField(required=False, initial=True,
+                help_text=_("This will copy %(count)s subpages.") % {'count': subpage_count})
+
     publish_copies = forms.BooleanField(required=False, initial=True)
 
     def clean_new_slug(self):

wagtail/wagtailadmin/templates/wagtailadmin/pages/copy.html

@@ -14,17 +14,14 @@
                 {% include "wagtailadmin/shared/field_as_li.html" with field=form.new_title %}
                 {% include "wagtailadmin/shared/field_as_li.html" with field=form.new_slug %}
 
-                {% if pages_to_copy.count > 1 %}
+                {% if form.copy_subpages %}
                     {% include "wagtailadmin/shared/field_as_li.html" with field=form.copy_subpages %}
-                    <li class="help">
-                        {% blocktrans with copy_page_count=pages_to_copy.count|add:'-1' %}This will copy {{ copy_page_count }} subpages.{% endblocktrans %}
-                    </li>
                 {% endif %}
 
                 {% if pages_to_publish.count and can_publish %}
                     {% include "wagtailadmin/shared/field_as_li.html" with field=form.publish_copies %}
                     <li class="help">
-                        {% blocktrans with live_page_count=pages_to_copy.live.count %}{{ live_page_count }} of the pages being copied are live. Would you like to publish their copies?{% endblocktrans %}
+                        {% blocktrans with live_page_count=pages_to_publish.count %}{{ live_page_count }} of the pages being copied are live. Would you like to publish their copies?{% endblocktrans %}
                     </li>
                 {% endif %}
             </ul>

wagtail/wagtailadmin/views/pages.py

@@ -687,7 +687,7 @@ def copy(request, page_id):
     if request.method == 'POST' and form.is_valid():
         # Copy the page
         new_page = page.copy(
-            recursive=form.cleaned_data['copy_subpages'],
+            recursive=form.cleaned_data.get('copy_subpages'),
             update_attrs={
                 'title': form.cleaned_data['new_title'],
                 'slug': form.cleaned_data['new_slug'],
@@ -705,7 +705,7 @@ def copy(request, page_id):
         new_page.get_descendants(inclusive=True).update(owner=request.user)
 
         # Give a success message back to the user
-        if form.cleaned_data['copy_subpages']:
+        if form.cleaned_data.get('copy_subpages'):
             messages.success(request, _("Page '{0}' and {1} subpages copied.").format(page.title, new_page.get_descendants().count()))
         else:
             messages.success(request, _("Page '{0}' copied.").format(page.title))
@@ -713,13 +713,10 @@ def copy(request, page_id):
         # Redirect to explore of parent page
         return redirect('wagtailadmin_explore', parent_page.id)
 
-    pages_to_copy = page.get_descendants(inclusive=True)
-
     return render(request, 'wagtailadmin/pages/copy.html', {
         'page': page,
-        'pages_to_copy': pages_to_copy,
         'parent_page': parent_page,
-        'pages_to_publish': pages_to_copy.live(),
+        'pages_to_publish': page.get_descendants(inclusive=True).live(),
         'can_publish': can_publish,
         'form': form,
     })