langchain

2c985995 - text-splitters: fix stale header metadata in ExperimentalMarkdownSyntaxTextSplitter (#31622)

text-splitters: fix stale header metadata in ExperimentalMarkdownSyntaxTextSplitter (#31622) **Description:** Previously, when transitioning from a deeper Markdown header (e.g., ###) to a shallower one (e.g., ##), the ExperimentalMarkdownSyntaxTextSplitter retained the deeper header in the metadata. This commit updates the `_resolve_header_stack` method to remove headers at the same or deeper levels before appending the current header. As a result, each chunk now reflects only the active header context. Fixes unexpected metadata leakage across sections in nested Markdown documents. Additionally, test cases have been updated to: - Validate correct header resolution and metadata assignment. - Cover edge cases with nested headers and horizontal rules. **Issue:** Fixes [#31596](https://github.com/langchain-ai/langchain/issues/31596) **Dependencies:** None **Twitter handle:** -> [_RaghuKapur](https://twitter.com/_RaghuKapur) **LinkedIn:** -> [https://www.linkedin.com/in/raghukapur/](https://www.linkedin.com/in/raghukapur/)