[mislavkos]

Summary

--lossless is meant to keep everything in the export. Rebuilding exports from lossless output (see the follow-up PR) showed where it didn't:

• Persistent stores (PersistentStoreCatalog, FileMaker 2026, SaXML 2.3.0.0) weren't exploded, so their values were lost. They now go to persistent_stores/.
• Carriage returns in calculation text were dropped where they were part of a CRLF line break, because prepare_xml_content split with str::lines().
• Indentation of calculation text: removing an item's indentation also removed tabs from continuation lines of CDATA and multi-line text values. Only markup lines are unindented now.
• The XML declaration is kept as the first line of the skeleton, since it differs between FileMaker versions.
• Modified fields (FileMaker 20–22): the ModifyAction section of these exports has one FieldCatalog per field. All of them were written to tables__modify_action/<table> - ID <id>.xml, so each overwrote the previous one and only the last field of each table survived. They're now written to tables__modify_action/<table> - ID <id>/<field> - ID <id>.xml, and the skeleton names the field as well, so the order is kept.
• File names derived from the content (accounts, relationships, libraries, modified layouts) are escaped like all other file names. A / in such a name made the write fail, so the file was missing.

Breaking change

Marked fix! because the output layout changes for FileMaker 20–22 exports: modified fields move from one file per table to one file per field. Anything that reads tables__modify_action/<table> - ID <id>.xml by path needs to follow. The first run after upgrading produces a large one-time diff, mostly fields that were missing until now: in one real-world export, about 1,500 new field files. Releasing this as 0.10.0 rather than a patch might be the clearer signal.

Other one-time changes on upgrade:

• persistent_stores/ appears for FileMaker 2026 exports that have persistent stores.
• Every skeleton.xml gains the declaration line (lossless only).
• Calculations with CRLF line breaks gain their \r.
• Files named after content with characters like | or ? are renamed, e.g. | becomes _.

Testing

• Unit tests for each fix; snapshots updated (declaration line, per-field files for fmSyntaxColorizer).
• Exploded 82 real exports (FileMaker 20 to 2026, UTF-8 and UTF-16, single files and split exports) with --lossless and rebuilt each from the output: all identical to the originals.
• About 3–5% slower on a 330 MB export.