feat: implement XML attachment file naming functionality (backport #253)

[mergify]

• Added E Invoice Settings field for global autonaming pattern for XML attachements.
• Added get_xml_attachment_file_base_name function to resolve file names.
• Introduced unit tests for various naming scenarios in test_xml_attachment_naming.py.
• Updated Sales Invoice logic to utilize the new naming function for XML file attachments.
• Integrated autonaming pattern into "Download XML" button on Sales Invoice.

Ref: IBT-164
closes #245

---

This is an automatic backport of pull request #253 done by Mergify.

[mergify]

Cherry-pick of d45a1f0 has failed:

On branch mergify/bp/version-15-hotfix/pr-253
Your branch is up to date with 'origin/version-15-hotfix'.

You are currently cherry-picking commit d45a1f0.
  (fix conflicts and run "git cherry-pick --continue")
  (use "git cherry-pick --skip" to skip this patch)
  (use "git cherry-pick --abort" to cancel the cherry-pick operation)

Changes to be committed:
	modified:   eu_einvoice/european_e_invoice/custom/sales_invoice.py
	new file:   eu_einvoice/european_e_invoice/custom/test_sales_invoice.py
	modified:   eu_einvoice/european_e_invoice/doctype/e_invoice_settings/e_invoice_settings.py

Unmerged paths:
  (use "git add <file>..." to mark resolution)
	both modified:   eu_einvoice/european_e_invoice/doctype/e_invoice_settings/e_invoice_settings.json
	both modified:   eu_einvoice/locale/de.po
	both modified:   eu_einvoice/locale/main.pot

To fix up this pull request, you can check it out locally. See documentation: https://docs.github.com/en/pull-requests/collaborating-with-pull-requests/reviewing-changes-in-pull-requests/checking-out-pull-requests-locally

[greptile-apps]

Greptile Summary

This backport (from #253) introduces configurable XML attachment file naming for Sales Invoices: a new auto_name_format_for_xml_file field in E Invoice Settings lets users define a Frappe naming-series pattern, resolved at runtime by the new get_xml_attachment_file_base_name helper with graceful fallback to doc.name. The backport merge was not cleanly resolved, leaving raw Git conflict markers committed in three files.

• sales_invoice.py / e_invoice_settings.py / test file: Python changes are correct — the naming helper, _no_series_counter, and the updated download_xrechnung / _attach_xml_file call-sites are all well-implemented and covered by 8 unit tests.
• e_invoice_settings.json: Contains unresolved conflict markers; the file is invalid JSON and Frappe cannot load the DocType definition from it.
• de.po / main.pot: Both locale files also contain conflict markers at multiple locations, invalidating them as gettext files and losing all German translations.

Confidence Score: 1/5

Not safe to merge — three committed files are broken due to unresolved backport merge conflicts.

The Python implementation and tests are solid, but e_invoice_settings.json is invalid JSON with literal conflict markers, meaning Frappe will fail to load the E Invoice Settings DocType entirely. Both locale files (de.po, main.pot) are also corrupted by the same unresolved conflict, breaking German translations. These files must be corrected before merging.

e_invoice_settings.json, de.po, and main.pot all require manual conflict resolution before this backport can be merged.

Important Files Changed

Filename	Overview
eu_einvoice/european_e_invoice/custom/sales_invoice.py	Adds get_xml_attachment_file_base_name and _no_series_counter; updates download_xrechnung and _attach_xml_file to use the new naming helper. Python code is clean, logic is correct, and fallback behavior is well-handled.
eu_einvoice/european_e_invoice/custom/test_sales_invoice.py	New test file covering 8 naming scenarios including empty patterns, field interpolation, hash/series segments, slash sanitization, and fallback to doc.name.
eu_einvoice/european_e_invoice/doctype/e_invoice_settings/e_invoice_settings.json	Contains unresolved Git merge conflict markers making the file invalid JSON; Frappe cannot parse this DocType definition, breaking the entire E Invoice Settings loading path.
eu_einvoice/european_e_invoice/doctype/e_invoice_settings/e_invoice_settings.py	Adds auto_name_format_for_xml_file: DF.Data
eu_einvoice/locale/de.po	Contains unresolved Git merge conflict markers at multiple locations, making the file invalid gettext format and breaking German translations for the module.
eu_einvoice/locale/main.pot	Contains unresolved Git merge conflict markers (same backport conflict as de.po), making the template file unparseable by Babel/gettext tooling.

Flowchart

%%{init: {'theme': 'neutral'}}%%
flowchart TD
    A[download_xrechnung / _attach_xml_file] --> B[get_xml_attachment_file_base_name]
    B --> C{pattern provided?}
    C -- No --> D[frappe.get_single_value E Invoice Settings]
    D --> E{pattern empty or whitespace?}
    C -- Yes --> E
    E -- Yes --> F[get_safe_file_name doc.name]
    E -- No --> G[parse_naming_series with _no_series_counter]
    G --> H{resolve succeeded?}
    H -- Exception --> I[log_error] --> F
    H -- Empty string --> F
    H -- Non-empty base --> J[get_safe_file_name base]
    J --> K[base_name + .xml]
    F --> K

Loading

_{Reviews (1): Last reviewed commit: "feat: implement XML attachment file nami..." | Re-trigger Greptile}

[dafrose]

Conflicts are resolved and I added a _get_safe_filename local helper, because it did not exist in frappe v15.