Classic metafile stock drawing state

Pinned TortoiseGit 7338078f8ddd924b8cddee35f512f2286072136d accepts WMF/EMF in TortoiseIDiff/MainWindow.cpp:1255 and loads the image through Windows GDI+ in Utils/MiscUI/Picture.cpp:418. TurtleGit interprets captured records in its bundled bounded renderer before displaying private image pixels. Repository and conflict-stage bytes remain the original metafile. This family extends the existing image workflow; it adds no dialog setting or persistent per-document color preference.

Stock handles and real recording behavior

The MS-EMF StockObject enumeration defines DC_BRUSH as stock index 18 and DC_PEN as index 19 for EMF playback. Their initial colors follow white brush and black pen respectively. Selecting one of these handles must select its drawing-context object, rather than fail object lookup, reuse a previously selected ordinary object or silently remove its ink. Stock selection remains distinct from creation and deletion of ordinary objects.

The GetStockObject API also describes live SetDCBrushColor and SetDCPenColor calls. API behavior does not establish a serialized EMF color-setter record. The inspected Wine recording implementation in gdi32/emfdc.c at 7298a818 emits ordinary brush/pen creation and selection for these color changes. The renderer therefore accepts the actual create/select replacement sequence; this family invents no EMR_SETDCBRUSHCOLOR or EMR_SETDCPENCOLOR record. An ordinary red brush remains distinct from the default white stock brush when the recording later selects the stock handle again.

SaveDC and RestoreDC retain drawing-context selections and related color state. Existing vector, pen-outline, brush, region, flood and raster consumers must resolve their paint from that current state. A saved selection cannot be flattened into whatever ordinary brush or pen happens to be selected after the save. The existing clip, transform, ROP and aggregate painting budgets still apply.

Palette boundaries

DEFAULT_PALETTE is a stock logical palette whose actual system colors are device dependent. TurtleGit uses an explicit common Windows display adaptation: the twenty-entry default logical palette described by Microsoft's default palette documentation. This supports ordinary indexed-color playback without claiming a universal printer, custom display or hardware palette. Palette identity, selection and Save/Restore remain part of the drawing context; existing explicit logical palette objects retain their recorded entries and edits.

Indices outside the represented logical palette and PC_EXPLICIT hardware indices still refuse the whole conversion. The fixed display profile is a macOS compatibility policy, not a physical Windows device measurement or a claim that every device uses these exact colors.

Native integration and verification scope

The grouped native case uses the real FileComparisonWindowController and ImageConflictWindowController, the packaged asynchronous decoder, independent record controls and actual private Git conflict stages. It checks decoded image pixels, source-byte preservation and reload behavior. Final functional automation uses a receiver-only frame-constraint override, places every test-owned window outside the union of all desktop screens and checks that no frame intersects a screen. Owners close and decoder requests drain before releasing private inputs.

The retained full-window light/dark photographs came from an earlier owned capture attempt against the same production UI. AppKit constrained those window frames to leave a 40-pixel-wide desktop edge; those photographs must not be described as fully offscreen captures. After strict offscreen placement was implemented, ScreenCaptureKit returned internal start error -3811 on all three bounded attempts. No further compositor attempts or substitute pictures were used. The final functional check therefore runs without capture; the earlier actual photographs are separate visual evidence and do not replace pixel or ownership assertions.

Actual grouped results and focused repairs are recorded separately in the dated QA evidence after checks finish; no passing result is inferred here from source inspection. Existing signed runtime checks cover their earlier measured corpus only.

Windows device-palette identity, exact GDI raster edge stepping, arbitrary device objects, unimplemented records, physical image-window acceptance and current signed deployment remain open. See the central metafile scope, classic brush contract and classic pen contract. This family does not declare complete WMF, EMF or TortoiseGit image parity.