Refuse to park a track whose pre-park snapshot is gone, rather than re-snapshotting the already-parked chain as the user's state

src/shell/view/view.cpp

@@ -31,6 +31,7 @@
 #define REAPERAPI_WANT_SetMediaTrackInfo_Value
 #define REAPERAPI_WANT_GetSetMediaTrackInfo_String
 #define REAPERAPI_WANT_PreventUIRefresh
+#define REAPERAPI_WANT_ShowConsoleMsg
 #define REAPERAPI_WANT_Undo_BeginBlock2
 #define REAPERAPI_WANT_Undo_EndBlock2
 #define REAPERAPI_WANT_TrackList_AdjustWindows
@@ -107,16 +108,6 @@ void applyTransparentLaneDisplay(MediaTrack* tr) {
                             static_cast<double>(settings | kLaneSettingsHideButtons));
 }
 
-const char* flagParm(Flag f) {
-    switch (f) {
-        case Flag::ShowInTcp:   return "B_SHOWINTCP";
-        case Flag::ShowInMixer: return "B_SHOWINMIXER";
-        case Flag::MainSend:    return "B_MAINSEND";
-        case Flag::FxEnable:    return "I_FXEN";
-    }
-    return "B_SHOWINTCP";  // unreachable; keeps the compiler quiet
-}
-
 // The master track is not enumerated by GetTrack (index space excludes it),
 // so it can never enter the tree — the master-untouched invariant holds by
 // construction.
@@ -185,7 +176,7 @@ bool writeIfChanged(MediaTrack* tr, const char* parm, double value) {
 
 void applyFlags(MediaTrack* tr, const std::vector<TrackFlagOp>& flags, int& undoMask) {
     for (const TrackFlagOp& op : flags) {
-        if (!writeIfChanged(tr, flagParm(op.flag), static_cast<double>(op.value))) continue;
+        if (!writeIfChanged(tr, trackFlagParm(op.flag), static_cast<double>(op.value))) continue;
         // I_FXEN is the only FX-domain flag driven here, so it is the only one
         // whose undo record has to carry UNDO_STATE_FX.
         if (op.flag == Flag::FxEnable) undoMask |= UNDO_STATE_FX;
@@ -449,6 +440,7 @@ bool applyMode(ViewModeModel& model, const std::string& targetModeId, ReaProject
 
     int undoMask = kApplyUndoMask;
     bool laneModeChanged = false;
+    int refusedParks = 0;
 
     Undo_BeginBlock2(proj);
     {
@@ -470,13 +462,22 @@ bool applyMode(ViewModeModel& model, const std::string& targetModeId, ReaProject
             MediaTrack* tr = resolve(trackByGuid, guid);
             if (!tr) continue;  // stale GUID — prune
 
+            // Full contract at decidePark. Only an absent snapshot can refuse, so
+            // the short-circuit cannot change the answer (ParkOnly ignores the
+            // second term); a first park still pays the four reads, a reapply's
+            // re-park of a still-parked track does not.
+            const bool haveSnapshot = model.snapshot(guid) != nullptr;
+            const ParkAction action = decidePark(
+                haveSnapshot,
+                !haveSnapshot &&
+                    parkFlagsAlreadyApplied(tp.flags, readParkFlagValues(tr, tp.flags)));
+            if (action == ParkAction::Refuse) { ++refusedParks; continue; }
+
             // Enqueued FIRST: a park landing on this track's own pending restore
             // cancels it, and those ops are then the only surviving record of the
-            // pre-park FX state. Snapshot ONCE — a snapshot already present means
-            // the track is still parked, so recapturing would overwrite the true
-            // pre-park state with zeros and a later restore would hide it for good.
+            // pre-park FX state.
             const std::vector<FxOfflineOp> cancelled = deferFxPark(proj, guid);
-            if (model.snapshot(guid) == nullptr)
+            if (action == ParkAction::SnapshotThenPark)
                 model.storeSnapshot(guid, snapshotTrack(tr, cancelled));
             applyFlags(tr, tp.flags, undoMask);
         }
@@ -539,6 +540,13 @@ bool applyMode(ViewModeModel& model, const std::string& targetModeId, ReaProject
     if (laneModeChanged) UpdateTimeline();
 
     Undo_EndBlock2(proj, undoLabel.c_str(), undoMask);
+
+    // After the undo block and the UI hold: a refusal is a report, not a project
+    // write, and it must not join what a Ctrl-Z rolls back. "!SHOW:" so an
+    // unattended project-load reapply cannot force the console open
+    // (reaper_plugin_functions.h:6536), same as the drain's drop report.
+    const std::string refusedMsg = describeRefusedParks(refusedParks);
+    if (!refusedMsg.empty()) ShowConsoleMsg(("!SHOW:" + refusedMsg).c_str());
     return true;
 }