---
fixes:
  - |
    When using the **MarkdownHeaderSplitter**, in the split chunks, the child header previously lost
    its direct parent header in the metadata. Previously if one executed the code below:

    .. code:: python
      from haystack.components.preprocessors import MarkdownHeaderSplitter
      from haystack import Document

      text = """
      # header 1
      intro text

      ## header 1.1
      text 1

      ## header 1.2
      text 2

      ### header 1.2.1
      text 3

      ### header 1.2.2
      text 4
      """

      document = Document(content=text)

      splitter = MarkdownHeaderSplitter(
              keep_headers=True,
              secondary_split="word"
      )
      result = splitter.run(documents=[document])["documents"]

      for doc in result:
          print(f"Header: {doc.meta['header']}, parent headers: {doc.meta['parent_headers']}")

    We would have expected this output:

    .. code:: text

      Header: header 1, parent headers: []
      Header: header 1.1, parent headers: ['header 1']
      Header: header 1.2, parent headers: ['header 1']
      Header: header 1.2.1, parent headers: ['header 1', 'header 1.2']
      Header: header 1.2.2, parent headers: ['header 1', 'header 1.2']

    But instead we actually got:

    .. code:: text
      Header: header 1, parent headers: []
      Header: header 1.1, parent headers: []
      Header: header 1.2, parent headers: ['header 1']
      Header: header 1.2.1, parent headers: ['header 1']
      Header: header 1.2.2, parent headers: ['header 1', 'header 1.2']

    The error happened when a parent header had its own content chunk before the first
    child header.

    This has been fixed so even when a parent header has its own content chunk before the first child header all content is preserved.