Description:
When opening an XML file formatted as DocBook (DTD 4.1.2) in Writer, editing its content, and attempting to re-save it, the process consistently fails with a write error.

Steps to Reproduce:
1. Create a file named test.xml with UTF-8 encoding and paste the following XML content:

 <?xml version="1.0" encoding="UTF-8"?>
 <!DOCTYPE article PUBLIC "-//OASIS//DTD DocBook XML V4.1.2//EN" "http://www.oasis-open.org/docbook/xml/4.1.2/docbookx.dtd">
 <article lang="">
   <para>Test</para>
 </article>

2. Open LibreOffice Writer (or start LibreOffice).
3. Go to File Menu → Open… (Ctrl+OCtrl+O).
4. Select and open the test.xml file. The file opens in Writer’s edit mode (without the visible XML tags).
5. Edit the content (e.g., add a character to the paragraph, like “Test 1”).
6. Go to File Menu → Save (Ctrl+SCtrl+S).
7. The “Non-Standard File Format” warning dialog will appear.
8. Click the “Use DocBook format” button.


Actual Results:
After Step 8, an error dialog titled “Error” appears, containing the following message:

    Error saving the document test:
    Write Error.
    The file could not be written.

The document is not saved.


Expected Results:
The document should be saved successfully, overwriting the test.xml file.


Reproducible: Always


User Profile Reset: Yes

Additional Info:
History and Additional Observations (Crucial for Diagnosis):

    100% Reproducible: This write error is consistent and 100% reproducible exclusively when attempting to overwrite the DocBook XML file, as per the listed steps.

    Historical Context (Path/Encoding Issues):
        Previously (Identified in 2020): The local (offline) help failed to open if the LibreOffice installation path contained non-ASCII characters (e.g., accented characters). This was attributed to a failure in encoding the URI of the local file path.
        Fix and Possible Regression/Side Effect (Estimated 2022): An update fixed the local help issue (correct URI encoding). However, the problem of intermittent write errors when saving any file (Writer or Calc) persisted or emerged if the installation path still contained non-ASCII characters.
        Personal Mitigation (Action that resolved intermittency): To stop the intermittent write errors, LibreOffice was installed in a path without accented characters (pure ASCII). This action made the intermittent errors disappear completely.

    Current Conclusion (The Problem Connection):
        Despite using a pure ASCII installation path (which resolved intermittent issues), the write error persists and is constant in the specific scenario of overwriting the DocBook file.
        Inference/Hypothesis: The write error in the DocBook filter (consistent) manifests the same error message that occurred in other (intermittent) scenarios involving non-ASCII installation paths. This suggests that the DocBook filter’s specific save routine may be utilizing path or file URI handling logic that ignores the fixes implemented in the native filters (for ODT/ODS), or that it remains vulnerable to the original encoding problem, failing even when the path is pure ASCII.

    Ethics Statement:
        This report was constructed and translated with the aid of generative AI for the sole purpose of ensuring the text is concise, organized, and technically fluent.

Version: 25.8.2.2 (X86_64)
Build ID: d401f2107ccab8f924a8e2df40f573aab7605b6f
CPU threads: 8; OS: Windows 11 X86_64 (build 26200); UI render: Skia/Raster; VCL: win
Locale: pt-BR (pt_BR); UI: pt-BR
Calc: CL threaded