Fix drag-out losing audio and FX-container drops losing the capture; re-home ingest under shell/actions

CMakeLists.txt

@@ -1129,7 +1129,7 @@ add_library(reaper_reasampler MODULE
     src/shell/actions/design_view_actions.cpp
     src/shell/actions/bank_actions.cpp
     src/shell/actions/prune_action.cpp
-    src/ingest.cpp
+    src/shell/actions/ingest.cpp
     src/core/model/bank_book.cpp
     src/core/model/bank_book_json.cpp
     src/core/model/owned_manifest.cpp

src/app/main.cpp

@@ -22,7 +22,7 @@
 
 #include "core/capture/render_settings.h"        // captureActionTable
 #include "core/version/app_version.h"            // appVersion
-#include "ingest.h"
+#include "shell/actions/ingest.h"
 #include "shell/actions/action_registry.h"       // the registration table
 #include "shell/actions/bank_actions.h"          // multi-bank action family
 #include "shell/actions/design_view_actions.h"   // Design View action family

src/core/ui/drag_out.cpp

@@ -48,4 +48,11 @@ PathList assemblePathList(const std::vector<ResolvedSample>& resolved) {
     return out;
 }
 
+OsHandoff decideOsHandoff(const std::vector<std::string>& paths) {
+    OsHandoff out;
+    out.startOsDrag = !paths.empty();
+    out.releaseInternalDrag = out.startOsDrag;
+    return out;
+}
+
 } // namespace reasampler::ui

src/core/ui/drag_out.h

@@ -69,4 +69,19 @@ struct PathList {
 // exact-string — the shell normalizes case/slashes upstream if it wants Windows-style dedup.
 PathList assemblePathList(const std::vector<ResolvedSample>& resolved);
 
+// --- OS hand-off ordering -----------------------------------------------------
+
+// The two side effects the shell performs when a drag crosses out of REAPER. They are ONE
+// decision, not two: winding the internal drag down (release capture, clear drag state) for a
+// hand-off that then cannot happen consumes the gesture — the user sees a drag that silently
+// did nothing and drags again. Never release without starting.
+struct OsHandoff {
+    bool startOsDrag = false;         // hand `paths` to the OS drag initiator
+    bool releaseInternalDrag = false; // first wind down mouse capture + panel drag state
+};
+
+// Decides the hand-off from the assembled path list. Empty (everything stale/unresolvable)
+// means the internal drag stays live rather than dying half-torn-down.
+OsHandoff decideOsHandoff(const std::vector<std::string>& paths);
+
 } // namespace reasampler::ui

src/core/wire/instrument_drop.cpp

@@ -76,6 +76,17 @@ std::vector<std::uint8_t> buildInstrumentDropPreset(const std::string& sampleId)
     return buildVstPresetBytes(vstClassIdHex(), instrumentDropStateBytes(sampleId));
 }
 
+DropOutcome decideDropOutcome(const DropAttempt& attempt) {
+    DropOutcome out;
+    if (attempt.addedFxIndex < 0) return out;  // add failed — nothing exists to roll back
+    if (!attempt.presetApplied) {
+        out.rollbackFxIndex = attempt.addedFxIndex;
+        return out;
+    }
+    out.loaded = true;
+    return out;
+}
+
 bool infoNamesFxHotspot(const std::string& info) {
     // See the header contract for the prefix rule and the embed-strip exclusion.
     auto startsWith = [&info](const char* p) { return info.rfind(p, 0) == 0; };

src/core/wire/instrument_drop.h

@@ -68,4 +68,25 @@ bool infoNamesFxHotspot(const std::string& info);
 // assert the capture is selected. Not called by the shell.
 std::vector<std::uint8_t> instrumentDropStateBytes(const std::string& sampleId);
 
+// --- All-or-nothing rollback --------------------------------------------------
+
+// What the shell observed while executing one drop, reduced to the two REAPER
+// results the contract turns on.
+struct DropAttempt {
+    int  addedFxIndex = -1;    // TrackFX_AddByName's return; < 0 = nothing was created
+    bool presetApplied = false;  // TrackFX_SetPreset's return
+};
+
+// The verdict. `rollbackFxIndex >= 0` obliges the caller to TrackFX_Delete it before
+// returning — an instance whose capture never landed must not survive the drop.
+struct DropOutcome {
+    bool loaded = false;
+    int  rollbackFxIndex = -1;
+};
+
+// Pure so the contract is provable without a DAW: the rollback obligation is decided
+// here, not inline in the shell, and holds identically for every drop surface (FX
+// button, FX chain/container, Media-Explorer import).
+DropOutcome decideDropOutcome(const DropAttempt& attempt);
+
 }  // namespace reasampler::wire

src/shell/actions/CLAUDE.md

@@ -37,13 +37,11 @@ is owned by other directories and only skinned here.
 
 ## Gotchas
 
-- **Structural wart, not yet fixed:** `ingest.cpp` / `ingest.h`, plus `ext_keys.h`
-  and `resource.h`, physically live at `src/` root rather than under
-  `shell/actions/` — Phase Q's reorg did not re-home these files into
-  `core/`/`shell/`/`app/`. `ingest` is documented here as its nearest sibling by
-  role, but the files themselves are not in this directory. This is a code
-  organization issue, not a documentation one — see Open questions in the
-  originating dispatch report.
+- **Structural wart, partly closed:** `ingest.cpp` / `ingest.h` now live in this
+  directory. `ext_keys.h` and `resource.h` still sit at `src/` root: `ext_keys.h`
+  is consumed mostly from `shell/instrument/`, so it is not this directory's to
+  claim, and `resource.h` is a build input paired with `src/resource.rc` (the SWELL
+  resgen step) rather than a shell module.
 - Media-Explorer import is single-file, pull-on-action (`OpenMediaExplorer` +
   `MediaExplorerGetLastPlayedFileInfo`) — there is no enumerate-selected-files or
   register-a-drop-handler API on the Media Explorer surface.

src/shell/actions/drag_out_win.cpp

@@ -62,6 +62,29 @@ HGLOBAL buildHDrop(const std::vector<std::string>& paths) {
     return h;
 }
 
+// COM reference counts MUST be interlocked. A CF_HDROP target is free to marshal the data
+// object into another apartment and finish the copy on a background thread AFTER DoDragDrop
+// has returned (Explorer's async file copy does exactly this). A plain ++/-- there races the
+// source thread's post-DoDragDrop Release: one lost increment destroys the object — and with
+// it the source HGLOBAL — before the target reads it, and the drop lands with no file. That
+// race is intermittent and a retry usually wins it; do not "simplify" these back.
+inline ULONG comAddRef(volatile LONG& refs) {
+    return static_cast<ULONG>(InterlockedIncrement(&refs));
+}
+
+// DoDragDrop requires the calling thread to be OLE-initialized — CoInitialize alone is not
+// enough, and an uninitialized thread fails the call outright, so the drag never starts.
+// Relying on REAPER having done it is a first-use hazard: whether it has depends on what else
+// ran first in the session. OleInitialize is per-thread refcounted, so this is additive to
+// whatever the host did; we deliberately never OleUninitialize — the extension lives for the
+// process, and unbalancing a REAPER-owned apartment is the hazard worth avoiding, not this.
+// RPC_E_CHANGED_MODE means the thread joined an MTA, where OLE drag-drop is unavailable.
+bool ensureOleForThisThread() {
+    static thread_local int state = 0;  // 0 untried, 1 ready, -1 unavailable
+    if (state == 0) state = SUCCEEDED(OleInitialize(nullptr)) ? 1 : -1;
+    return state > 0;
+}
+
 // Minimal IDropSource: continue until the (left) button releases or Escape cancels; always
 // request the copy cursor. This is the standard textbook drop source — no custom feedback.
 class DropSource final : public IDropSource {
@@ -76,11 +99,11 @@ public:
         *ppv = nullptr;
         return E_NOINTERFACE;
     }
-    ULONG STDMETHODCALLTYPE AddRef() override { return ++refs_; }
+    ULONG STDMETHODCALLTYPE AddRef() override { return comAddRef(refs_); }
     ULONG STDMETHODCALLTYPE Release() override {
-        const ULONG r = --refs_;
+        const LONG r = InterlockedDecrement(&refs_);
         if (r == 0) delete this;
-        return r;
+        return static_cast<ULONG>(r);
     }
     // IDropSource
     HRESULT STDMETHODCALLTYPE QueryContinueDrag(BOOL escapePressed, DWORD keyState) override {
@@ -92,7 +115,7 @@ public:
         return DRAGDROP_S_USEDEFAULTCURSORS;  // let OLE draw the standard copy cursor
     }
 private:
-    ULONG refs_ = 1;
+    volatile LONG refs_ = 1;
 };
 
 // Minimal IDataObject exposing exactly one format (CF_HDROP / TYMED_HGLOBAL). The HDROP is
@@ -112,11 +135,11 @@ public:
         *ppv = nullptr;
         return E_NOINTERFACE;
     }
-    ULONG STDMETHODCALLTYPE AddRef() override { return ++refs_; }
+    ULONG STDMETHODCALLTYPE AddRef() override { return comAddRef(refs_); }
     ULONG STDMETHODCALLTYPE Release() override {
-        const ULONG r = --refs_;
+        const LONG r = InterlockedDecrement(&refs_);
         if (r == 0) delete this;
-        return r;
+        return static_cast<ULONG>(r);
     }
 
     // IDataObject — the two that matter for a drag source.
@@ -184,7 +207,7 @@ private:
                (fe.tymed & TYMED_HGLOBAL) &&
                fe.dwAspect == DVASPECT_CONTENT;
     }
-    ULONG refs_ = 1;
+    volatile LONG refs_ = 1;
     HGLOBAL hdrop_ = nullptr;
 };
 
@@ -192,10 +215,8 @@ private:
 
 bool initiateDragOut(HWND__* /*panelHwnd*/, const std::vector<std::string>& absolutePaths) {
     if (absolutePaths.empty()) return false;
+    if (!ensureOleForThisThread()) return false;
 
-    // REAPER's main thread is already OLE-initialized (it hosts OLE drag targets); we
-    // deliberately do NOT call OleInitialize — pairing OleUninitialize across a
-    // REAPER-owned apartment is the kind of thing that bites.
     HGLOBAL hdrop = buildHDrop(absolutePaths);
     if (!hdrop) return false;
 

src/shell/actions/ingest.cpp

@@ -2,7 +2,7 @@
 // REAPER-facing, DAW-verified; the pure serialization it drives (assignment_request)
 // is CTest-tested.
 
-#include "ingest.h"
+#include "shell/actions/ingest.h"
 
 #include <cstdint>
 #include <cstring>

src/shell/actions/instrument_drop_win.cpp

@@ -20,6 +20,7 @@
 #define REAPERAPI_WANT_GetThingFromPoint
 #define REAPERAPI_WANT_TrackFX_AddByName
 #define REAPERAPI_WANT_TrackFX_Delete
+#define REAPERAPI_WANT_TrackFX_GetCount
 #define REAPERAPI_WANT_TrackFX_SetPreset
 #define REAPERAPI_WANT_Undo_BeginBlock2
 #define REAPERAPI_WANT_Undo_EndBlock2
@@ -29,6 +30,9 @@ namespace reasampler {
 
 // Real-namespace-home using-declarations (Q-W6: the namespaces.h shim is retired).
 using version::vstPluginName;
+using wire::decideDropOutcome;
+using wire::DropAttempt;
+using wire::DropOutcome;
 using wire::infoNamesFxHotspot;
 
 namespace {
@@ -99,25 +103,32 @@ bool loadInstrumentOntoTrack(MediaTrack* track, const std::vector<std::uint8_t>&
     // (beta extension <-> beta VST) has no literal to drift.
     const std::string fxName = "VST3:" + vstPluginName();
 
-    // Negative `instantiate` => always create a NEW instance. recFX = false: a
-    // normal track FX chain instance, not a record/monitoring FX.
-    const int fxIndex = TrackFX_AddByName(track, fxName.c_str(), /*recFX=*/false,
-                                          /*instantiate=*/-1);
-    bool ok = fxIndex >= 0;
+    // An EXPLICIT top-level insertion position (instantiate <= -1000 IS the position, -1000
+    // = first in chain), not the bare -1. Both always create a new instance; the bare form
+    // additionally leaves placement to REAPER's ambient FX-chain insert point, which a drop
+    // onto an FX container/chain-window moves — so the index handed to TrackFX_SetPreset and
+    // the instance just created stop denoting the same FX and the capture never lands. The
+    // bare-form retry keeps the reference path alive if the positional form is ever refused.
+    // recFX = false: a normal track FX chain instance, not a record/monitoring FX.
+    const int insertPos = TrackFX_GetCount(track);
+    int fxIndex = TrackFX_AddByName(track, fxName.c_str(), /*recFX=*/false,
+                                    /*instantiate=*/-1000 - insertPos);
+    if (fxIndex < 0)
+        fxIndex = TrackFX_AddByName(track, fxName.c_str(), /*recFX=*/false, /*instantiate=*/-1);
 
     // u8string() gives UTF-8 bytes on MSVC (not ACP-converted), so a temp dir under
     // an accented or CJK user-name is handled correctly by REAPER's path APIs.
-    if (ok) ok = TrackFX_SetPreset(track, fxIndex, presetPath.u8string().c_str());
+    DropAttempt attempt;
+    attempt.addedFxIndex = fxIndex;
+    if (fxIndex >= 0)
+        attempt.presetApplied = TrackFX_SetPreset(track, fxIndex, presetPath.u8string().c_str());
 
     std::error_code ec;
     std::filesystem::remove(presetPath, ec);  // transient regardless of outcome
 
-    // All-or-nothing: if the preset apply fails, remove the FX instance we just
-    // added so the track is left exactly as it was.
-    if (!ok && fxIndex >= 0) {
-        TrackFX_Delete(track, fxIndex);
-    }
-    return ok;
+    const DropOutcome outcome = decideDropOutcome(attempt);
+    if (outcome.rollbackFxIndex >= 0) TrackFX_Delete(track, outcome.rollbackFxIndex);
+    return outcome.loaded;
 }
 
 bool performInstrumentDrop(MediaTrack* track, const std::vector<std::uint8_t>& presetBytes) {

src/shell/capture/capture_orchestrator.cpp

@@ -12,7 +12,7 @@
 #include "shell/panel/panel_input.h"           // bankPanelTailSetting / bankPanelRefresh
 #include "core/capture/tail_control.h"         // TailSetting
 #include "core/model/provenance.h"             // model::Provenance
-#include "ingest.h"                            // ingestAssignActiveInstance
+#include "shell/actions/ingest.h"              // ingestAssignActiveInstance
 #include "shell/persist/session.h"             // ReaSamplerSession
 #include "shell/capture/insert.h"              // runInsert / InsertRequest
 #include "shell/capture/realtime_lifecycle.h"  // the in-flight realtime state

src/shell/panel/panel_drag.cpp

@@ -298,8 +298,13 @@ void onMouseMove(int x, int y) {
 
         if (gesture == DragGesture::OsDrag) {
             // Resolve the payload to existing on-disk paths BEFORE tearing down internal
-            // drag state (the resolver reads dragSourceBankId / dragSampleIds).
+            // drag state (the resolver reads dragSourceBankId / dragSampleIds), then let the
+            // pure rule couple the two side effects: an unresolvable payload must leave the
+            // internal drag intact rather than wind it down for a hand-off that never runs —
+            // a half-torn-down drag reads to the user as "the drag did nothing, try again".
             const std::vector<std::string> paths = resolveDragPathsForOs();
+            const ui::OsHandoff handoff = ui::decideOsHandoff(paths);
+            if (!handoff.releaseInternalDrag) return;
 
             // DoDragDrop runs its own modal loop and takes over mouse capture, so the internal
             // drag must be fully wound down first.
@@ -313,8 +318,7 @@ void onMouseMove(int x, int y) {
             g_panel.dragPrimaryId.clear();
             invalidatePanel();
 
-            // Empty path list -> nothing draggable (all stale/missing); do not start a drag.
-            if (!paths.empty())
+            if (handoff.startOsDrag)
                 initiateDragOut(g_panel.hwnd, paths);  // COPY-ONLY; blocking on Windows
             return;
         }
@@ -377,14 +381,27 @@ void resetDragState() {
 // OsDragOut is never seen here: the pointer-left-client handoff happens live in onMouseMove.
 void onLBtnUp(int x, int y) {
     if (g_panel.dragging) {
-        // Drop-and-load: a release while hover-tracking a valid FX hotspot instantiates a
-        // ReaSampler 9000 on that track preloaded with the dragged capture — NOT a bank move,
-        // NOT an OS drag, NEVER a timeline insert. Takes priority over the in-grid / cross-bank
-        // drop. Single-capture only, so dragSampleIds.front() is the capture.
-        if (g_panel.instrumentDropTrack && g_panel.dragSampleIds.size() == 1) {
+        // Drop-and-load: a release over a valid FX hotspot instantiates a ReaSampler 9000 on
+        // that track preloaded with the dragged capture — NOT a bank move, NOT an OS drag,
+        // NEVER a timeline insert. Takes priority over the in-grid / cross-bank drop.
+        // Single-capture only, so dragSampleIds.front() is the capture.
+        //
+        // Re-resolve at the RELEASE point rather than trusting only the hover-tracked target:
+        // WM_MOUSEMOVE is coalesced, so a fast drag onto a dense surface (an FX chain row, a
+        // container) can release over a hotspot no processed move ever reported. Strictly
+        // additive — a release-point miss falls back to the tracked target, so the
+        // hover-then-release-on-the-FX-button path is untouched.
+        const bool singleCapture = g_panel.dragSampleIds.size() == 1;
+        MediaTrack* dropTrack = g_panel.instrumentDropTrack;
+        if (singleCapture) {
+            POINT sp{x, y};
+            ClientToScreen(g_panel.hwnd, &sp);
+            const FxDropTarget fx = resolveFxDropTarget(sp.x, sp.y);
+            if (fx.valid()) dropTrack = fx.track;
+        }
+        if (dropTrack && singleCapture) {
             const std::string sampleId = g_panel.dragSampleIds.front();
-            performInstrumentDrop(g_panel.instrumentDropTrack,
-                                  buildInstrumentDropPreset(sampleId));
+            performInstrumentDrop(dropTrack, buildInstrumentDropPreset(sampleId));
             // Read-only over the bank + arrange: the only mutations are the new FX instance +
             // its state (both undoable in performInstrumentDrop).
         } else {

src/shell/panel/panel_window.cpp

@@ -14,7 +14,7 @@
 #include "shell/panel/panel_window.h"
 
 #include "shell/panel/draw_kit.h"
-#include "ingest.h"
+#include "shell/actions/ingest.h"
 
 #ifdef _WIN32
 #include <windowsx.h>  // GET_X_LPARAM / GET_Y_LPARAM (SWELL supplies them on mac/linux)

tests/test_drag_out.cpp

@@ -221,6 +221,52 @@ static void testMixedTallies() {
     CHECK(l.skippedDuplicate == 1);
 }
 
+// --- OS hand-off ordering -----------------------------------------------------
+//
+// The drag-out-lands-without-audio regression: the shell used to wind its internal drag down
+// (release capture, clear drag state) BEFORE checking whether the payload had resolved to any
+// on-disk file. A payload that resolved to nothing therefore consumed the gesture — the drag
+// died half-torn-down and the user saw a drop with no audio and dragged again. The two side
+// effects are one decision; these pin that.
+
+// Nothing draggable -> hand off nothing AND keep the internal drag alive.
+static void testEmptyPathsHandsOffNothingAndKeepsInternalDrag() {
+    const OsHandoff h = decideOsHandoff({});
+    CHECK(!h.startOsDrag);
+    CHECK(!h.releaseInternalDrag);
+}
+
+// A resolvable payload -> release the internal drag, then start the OS drag.
+static void testResolvablePayloadHandsOff() {
+    const OsHandoff one = decideOsHandoff({"C:/proj/bank/a.wav"});
+    CHECK(one.startOsDrag);
+    CHECK(one.releaseInternalDrag);
+    const OsHandoff many = decideOsHandoff({"a.wav", "b.wav", "c.wav"});
+    CHECK(many.startOsDrag);
+    CHECK(many.releaseInternalDrag);
+}
+
+// The coupling itself: releasing without starting is the defect, so it must be unreachable
+// for every input the assembler can produce.
+static void testNeverReleasesWithoutStarting() {
+    const std::vector<std::vector<std::string>> inputs = {
+        {}, {"a.wav"}, {"a.wav", "b.wav"}, {""},
+    };
+    for (const std::vector<std::string>& in : inputs) {
+        const OsHandoff h = decideOsHandoff(in);
+        CHECK(!(h.releaseInternalDrag && !h.startOsDrag));
+    }
+}
+
+// End to end through the assembler: a selection whose every entry is stale/unresolvable
+// yields the keep-the-drag verdict, which is exactly the case the shell used to mishandle.
+static void testAllSkippedSelectionKeepsInternalDrag() {
+    const PathList l = assemblePathList({missing("g1.wav"), unresolved()});
+    const OsHandoff h = decideOsHandoff(l.paths);
+    CHECK(!h.startOsDrag);
+    CHECK(!h.releaseInternalDrag);
+}
+
 int main() {
     testInsidePanelStaysInternal();
     testLeavingClientAreaIsOsDrag();
@@ -244,6 +290,11 @@ int main() {
     testAllSkippedYieldsEmpty();
     testMixedTallies();
 
+    testEmptyPathsHandsOffNothingAndKeepsInternalDrag();
+    testResolvablePayloadHandsOff();
+    testNeverReleasesWithoutStarting();
+    testAllSkippedSelectionKeepsInternalDrag();
+
     if (g_fail == 0) std::printf("All tests passed.\n");
     return g_fail ? 1 : 0;
 }

tests/test_instrument_drop.cpp

@@ -234,6 +234,72 @@ static void testEmbedStripIsNotHotspot() {
     CHECK(!infoNamesFxHotspot("mcp.fxembed extra"));
 }
 
+// --- Drop surface parity: container vs FX button ------------------------------
+//
+// The container-drop regression (instance loads, capture does not): the two surfaces must be
+// one code path carrying one payload. The payload is a function of the capture alone, so the
+// surface cannot influence it — and both surfaces must classify as hotspots so both reach it.
+
+// Every surface a drop can land on admits the SAME capture and yields a payload that decodes
+// back to it. The payload takes the capture and nothing else, so the surface cannot influence
+// it — walking the surfaces here is what pins that the container family is not second-class.
+static void testEveryDropSurfaceCarriesTheCapture() {
+    const char* surfaces[] = {
+        "fx_chain",  // FX chain window / container list — the reported failing surface
+        "fx_0",      // floating FX window
+        "tcp.fx",    // TCP FX button — the reference path
+        "mcp.fx",    // MCP FX button
+    };
+    const std::string sampleId = "cap-7f3a";
+    for (const char* info : surfaces) {
+        CHECK(infoNamesFxHotspot(info));
+        const ParsedPreset p = parsePreset(buildInstrumentDropPreset(sampleId));
+        CHECK(p.ok);
+        CHECK(p.classId == vstClassIdHex());
+        const ComponentState cs = deserializeComponentState(p.compChunk, kRate);
+        CHECK(cs.selectionId == sampleId);
+    }
+}
+
+// --- All-or-nothing rollback --------------------------------------------------
+
+// The add failed: nothing was created, so there is nothing to delete and nothing loaded.
+static void testAddFailureLeavesNothingToRollBack() {
+    const DropOutcome out = decideDropOutcome(DropAttempt{-1, false});
+    CHECK(!out.loaded);
+    CHECK(out.rollbackFxIndex < 0);
+}
+
+// The instance was created but the preset did not apply: the caller MUST delete that exact
+// index — an instance without its capture is the orphan the contract forbids.
+static void testPresetFailureRollsBackTheCreatedIndex() {
+    const DropOutcome zero = decideDropOutcome(DropAttempt{0, false});
+    CHECK(!zero.loaded);
+    CHECK(zero.rollbackFxIndex == 0);
+    const DropOutcome later = decideDropOutcome(DropAttempt{4, false});
+    CHECK(!later.loaded);
+    CHECK(later.rollbackFxIndex == 4);
+    // Container-addressed indices (0x2000000-flagged) roll back by the same rule — the
+    // obligation follows the index REAPER handed back, whatever space it names.
+    const DropOutcome inContainer = decideDropOutcome(DropAttempt{0x2000000 + 5, false});
+    CHECK(!inContainer.loaded);
+    CHECK(inContainer.rollbackFxIndex == 0x2000000 + 5);
+}
+
+// Both halves succeeded: loaded, and nothing to undo.
+static void testSuccessKeepsTheInstance() {
+    const DropOutcome out = decideDropOutcome(DropAttempt{2, true});
+    CHECK(out.loaded);
+    CHECK(out.rollbackFxIndex < 0);
+}
+
+// A "preset applied" report with no instance behind it can never read as loaded.
+static void testNoInstanceIsNeverLoaded() {
+    const DropOutcome out = decideDropOutcome(DropAttempt{-1, true});
+    CHECK(!out.loaded);
+    CHECK(out.rollbackFxIndex < 0);
+}
+
 int main() {
     testClassIdHexPinnedPerChannel();
     testPresetRoundTripsThroughInstrumentReader();
@@ -248,6 +314,12 @@ int main() {
     testNonFxSurfacesAreNotHotspot();
     testEmbedStripIsNotHotspot();
 
+    testEveryDropSurfaceCarriesTheCapture();
+    testAddFailureLeavesNothingToRollBack();
+    testPresetFailureRollsBackTheCreatedIndex();
+    testSuccessKeepsTheInstance();
+    testNoInstanceIsNeverLoaded();
+
     if (g_fail == 0) std::printf("All tests passed.\n");
     return g_fail ? 1 : 0;
 }