v6.12.0

• New Document::save(std::ostream &) and Document::save_to_memory(), which
  returns the saved document as an in-memory File. The path overloads are
  unchanged.

• The wasm binding gained edit(diff), save(), isEditable() and
  isSavable(), so a browser can save an edit back.

• Memory saves in the other bindings: save_to_memory() returns bytes in
  python, saveToMemory() byte[] in java, -saveToMemoryWithError: NSData
  in Objective-C.

• Two entries of the same zip document can be read at once; nothing serialises
  on a single lock any more.

• The zip backend is miniz/3.1.1, up from 3.0.2. Rendered output is
  unchanged.

• New FileType::hypertext_markup_language for html, htm, xhtml,
  text/html and application/xhtml+xml. Classification only: no open, no
  translate_html, and never detected from its bytes.

• Breaking An ods sheet stores a repeated cell once, at the range it
  covers, rather than once per position: SheetCell::position() reports the
  anchor of that range instead of the position the cell was looked up at, and
  Sheet::cell() hands back the same element everywhere in it.

• An ods table:number-columns-repeated beside a table:number-rows-repeated
  no longer inflates — the grid's own 1048576 × 1024 asked for three billion
  elements out of four hundred bytes.

• An xlsx <mergeCell> whose ref names more positions than the sheet has
  cells opens again; ref="A1:XFD1048576" used to visit all 17 billion.

• Decoding a spreadsheet costs about half the memory it did — pugixml is built
  in compact mode and the ods sheet index is sorted vectors rather than maps.
  A consumer that includes an internal header now needs PUGIXML_COMPACT, and
  the conan package declares it.

---

Features

• Name html as a file type, without a renderer for it (#769)
• Save to a stream or into memory, and bind edit/save in wasm (#778)

Performance

• Halve what a spreadsheet costs to decode, and stop two repeat bombs (#776)

Refactoring

• Make the archive's read callback re-entrant (#775)

Build

• Bump miniz to 3.1.1 (#774)

Publishing v6.12.0

• ✅ conan — success · conan package (conan.yml)
• ✅ maven — success · app.opendocument:odr-core-java — Maven Central + GitHub Packages
• ✅ android — success · app.opendocument:odr-core-android — Maven Central + GitHub Packages
• ✅ python — success · pyodr wheels — PyPI
• ✅ apple — success · OdrCoreObjC.xcframework — the release asset and its manifest
• ✅ wasm — success · @opendocument/odr-core — npm