From 968a99a76c3861b8e86813db487f705e4aec355f Mon Sep 17 00:00:00 2001
From: Andrew Hayzen <andrew.hayzen@kdab.com>
Date: Thu, 18 Jan 2024 16:55:14 +0000
Subject: [PATCH] block_builder: promotee tags might have siblings

eg

```html
<div>
    <blockquote></blockquote>
    <tag></tag>
    <blockquote></blockquote>
</div>
```

Needs to become
```html
<blockquote></blockquote>
<div>
    <tag></tag>
</div>
<blockquote></blockquote>
```

Before it became
```html
<blockquote></blockquote>
```

This solves the following crash
ValueError: Cannot replace one element with another when the element to be replaced is not part of a tree.

Related #141
---
 wagtail_wordpress_import/block_builder.py | 40 ++++++++++++++++++++++-
 1 file changed, 39 insertions(+), 1 deletion(-)

diff --git a/wagtail_wordpress_import/block_builder.py b/wagtail_wordpress_import/block_builder.py
index e0d6a5a8..26081b84 100644
--- a/wagtail_wordpress_import/block_builder.py
+++ b/wagtail_wordpress_import/block_builder.py
@@ -51,7 +51,45 @@ def promote_child_tags(self):
             promotees = self.soup.findAll(promotee)
             for promotee in promotees:
                 if promotee.parent.name in removee_tags:
-                    promotee.parent.replace_with(promotee)
+                    # Extract the promotee tag from a removee tag
+                    #
+                    # <div>
+                    #   <blockquote></blockquote>
+                    #   <tag></tag>
+                    #   <blockquote></blockquote>
+                    # </div>
+                    #
+                    # Needs to become
+                    # <blockquote></blockquote>
+                    # <div>
+                    #   <tag></tag>
+                    # </div>
+                    # <blockquote></blockquote>
+                    #
+                    # Before this change it became
+                    # <blockquote></blockquote>
+
+                    # This is the only item to replace the parent
+                    next_siblings_count = len(list(promotee.next_siblings))
+                    previous_siblings_count = len(list(promotee.previous_siblings))
+                    if next_siblings_count == 0 and previous_siblings_count == 0:
+                        promotee.parent.replace_with(promotee)
+                    # There are no more after this item move after the parent
+                    elif next_siblings_count == 0:
+                        promotee.parent.insert_after(promotee.extract())
+                    # There are no more before this item move after the parent
+                    elif previous_siblings_count == 0:
+                        promotee.parent.insert_before(promotee.extract())
+                    # This item is in the middle of a block so create a new block
+                    else:
+                        new_tag = self.soup.new_tag(promotee.parent.name, **promotee.parent.attrs)
+                        while promotee.next_sibling is not None:
+                            new_tag.append(promotee.next_sibling.extract())
+
+                        promotee.parent.insert_after(new_tag)
+                        # We want promotee to be before new_tag so insert second
+                        promotee.parent.insert_after(promotee.extract())
+
 
     def get_builder_function(self, element):
         """