From 023d0c42a76c54e50d49d1af956c41e2325f30a1 Mon Sep 17 00:00:00 2001
From: Frank Loemker <floemker@gmx.de>
Date: Sun, 14 Jan 2018 22:54:25 -0500
Subject: [PATCH] Support caller provided content when editing an article.

---
 src/wiki/forms.py         | 24 +++++++++++++++---------
 src/wiki/views/article.py |  8 ++++++--
 2 files changed, 21 insertions(+), 11 deletions(-)

diff --git a/src/wiki/forms.py b/src/wiki/forms.py
index 0ef95fc1..9c0177f5 100644
--- a/src/wiki/forms.py
+++ b/src/wiki/forms.py
@@ -234,7 +234,14 @@ class EditForm(forms.Form, SpamProtectionMixin):
         self.initial_revision = current_revision
         self.presumed_revision = None
         if current_revision:
-            initial = {'content': current_revision.content,
+            # For e.g. editing a section of the text: The content provided by the caller is used.
+            #      Otherwise use the content of the revision.
+            provided_content = True
+            content = kwargs.pop('content', None)
+            if content is None:
+                provided_content = False
+                content = current_revision.content
+            initial = {'content': content,
                        'title': current_revision.title,
                        'current_revision': current_revision.id}
             initial.update(kwargs.get('initial', {}))
@@ -249,18 +256,17 @@ class EditForm(forms.Form, SpamProtectionMixin):
                 data = kwargs.get('data', None)
             if data:
                 self.presumed_revision = data.get('current_revision', None)
-                if not str(
-                        self.presumed_revision) == str(
-                        self.initial_revision.id):
+                if not str(self.presumed_revision) == str(self.initial_revision.id):
                     newdata = {}
                     for k, v in data.items():
                         newdata[k] = v
                     newdata['current_revision'] = self.initial_revision.id
-                    newdata['content'] = simple_merge(
-                        self.initial_revision.content,
-                        data.get(
-                            'content',
-                            ""))
+                    # Don't merge if content comes from the caller
+                    if provided_content:
+                        self.presumed_revision = self.initial_revision.id
+                    else:
+                        newdata['content'] = simple_merge(
+                            content, data.get('content', ""))
                     newdata['title'] = current_revision.title
                     kwargs['data'] = newdata
                 else:
diff --git a/src/wiki/views/article.py b/src/wiki/views/article.py
index 3ead25e3..e63e2faa 100644
--- a/src/wiki/views/article.py
+++ b/src/wiki/views/article.py
@@ -225,6 +225,7 @@ class Edit(ArticleMixin, FormView):
 
     @method_decorator(get_article(can_write=True, not_locked=True))
     def dispatch(self, request, article, *args, **kwargs):
+        self.orig_content = kwargs.pop('content', None)
         self.sidebar_plugins = plugin_registry.get_sidebar()
         self.sidebar = []
         return super().dispatch(request, article, *args, **kwargs)
@@ -253,6 +254,7 @@ class Edit(ArticleMixin, FormView):
             kwargs['data'] = None
             kwargs['files'] = None
             kwargs['no_clean'] = True
+            kwargs['content'] = self.orig_content
         return form_class(self.request, self.article.current_revision, **kwargs)
 
     def get_sidebar_form_classes(self):
@@ -301,8 +303,10 @@ class Edit(ArticleMixin, FormView):
 
                         title = form.cleaned_data['unsaved_article_title']
                         content = form.cleaned_data['unsaved_article_content']
-
-                        if title != self.article.current_revision.title or content != self.article.current_revision.content:
+                        orig_content = self.orig_content
+                        if not orig_content:
+                            orig_content = self.article.current_revision.content
+                        if title != self.article.current_revision.title or content != orig_content:
                             request.session['unsaved_article_title_%d' % self.article.id] = title
                             request.session['unsaved_article_content_%d' % self.article.id] = content
                             messages.warning(
-- 
2.45.2