Commit and Rebase message wrapping

Pinned TortoiseGit: 7338078f8ddd924b8cddee35f512f2286072136d. This family covers the existing project message border, automatic line splitting and the selected-text Split lines command in Commit and Rebase message editors. It does not certify all Commit/Rebase dialogs or the whole port.

Source behavior

src/Utils/MiscUI/SciEdit.cpp:348–359 uses tgit.logwidthmarker to choose unwrapped horizontal editing with an edge marker when nonzero, and ordinary word-wrapped editing without the marker when zero. Installing a message or changing presentation does not itself split its saved text.

SciEdit.cpp:942–953,1315–1328 responds to text insertion/deletion by splitting logical lines in the union of the visible and edited range. The width is the configured column multiplied by the measured width of the space glyph. Automatic splitting inserts line endings; it does not join preexisting lines.

SciEdit.cpp:1191–1197,1231–1245 exposes Split lines for an editable editor with an edge column, enabling it only for a selection. Its explicit command first joins line endings through the selected target, then splits the affected logical lines at that measured width. ext/scintilla/src/Editor.cxx:1772–1825 defines the join rule: add a separating ASCII space unless the previous character was already an ASCII space. The target's first and last logical lines participate in splitting.

Native implementation checkpoint

The shared ProjectMessageTextView path supplies Commit and Rebase, retaining the existing project setting and model bindings. Nonzero width enables horizontal scrolling; zero width retains visual wrapping. The border and reflow measure the space glyph with the same eight-space tab policy used by the displayed editor. A localized Split lines item uses the existing source wrapping icon.

Automatic edits split the visible/edited logical range without joining it. The explicit command joins and splits as one native undo group, mapping selections through the edits. Marked input is deferred until composition completes. Initial message/settings installation does not reflow content or clear undo. Immediate Commit ownership and Rebase stopped-form identity fence edits and commands even before SwiftUI updates disabled controls. Read-only, busy, sheet/modal and retired owners reject mutations; closing an owner retires its retained editor.

The Debug app and four distinct Commit/Rebase case and Git-engine pairs pass cumulatively after fixture-only startup and cleanup repairs. The fixture checks loaded CRLF/decomposed Unicode, both width modes, automatic and selected reflow, Undo/Redo, marked composition, exact join rules, owner guards and unchanged HEAD/index. All six receiver attempts were reaped and independently confirmed absent. Batch evidence records actual results and failed attempts; the app build exited zero with one contradictory generic “failed with exit code 0” diagnostic. No Core production changed and no full Core suite was rerun for this native-only batch.

Remaining acceptance

New native line breaks use LF, matching the macOS platform convention; opening an existing message preserves its original line endings. Explicit joining recognizes CR/LF/CRLF rather than removing Unicode separator characters from user text. TextKit font shaping and line-break layout are native adaptations; exact Windows Scintilla pixel boundaries are not established by source mapping. Physical input methods, keyboard/VoiceOver, signed installed entry points, complete hosted CI and all upstream Commit/Rebase state/layout parity remain separate acceptance work.