fix(native): harden player teardown and shelf recovery

shared/apple/MpvPlayer/MpvPlayerCoreBase.swift

@@ -10,6 +10,14 @@ import QuartzCore
   import Metal
 #endif
 
+struct MpvLifecycleUnavailableError: LocalizedError {
+  let errorDescription: String?
+
+  init(_ description: String) {
+    errorDescription = description
+  }
+}
+
 protocol MpvPlayerDelegate: AnyObject {
   func onPropertyChange(name: String, value: Any?)
   func onEvent(name: String, data: [String: Any]?)
@@ -944,11 +952,7 @@ class MpvPlayerCoreBase: NSObject {
     pendingRequests.removeAll()
     pendingRequestsLock.unlock()
 
-    let error = NSError(
-      domain: "mpv",
-      code: -1,
-      userInfo: [NSLocalizedDescriptionKey: "Player disposed"]
-    )
+    let error = MpvLifecycleUnavailableError("Player disposed")
     for (_, request) in pending {
       DispatchQueue.main.async {
         switch request {
@@ -977,12 +981,8 @@ class MpvPlayerCoreBase: NSObject {
     return pendingRequests.removeValue(forKey: requestId)
   }
 
-  private func lifecycleUnavailableError() -> NSError {
-    NSError(
-      domain: "mpv",
-      code: -1,
-      userInfo: [NSLocalizedDescriptionKey: "Player is not initialized or has been disposed"]
-    )
+  private func lifecycleUnavailableError() -> MpvLifecycleUnavailableError {
+    MpvLifecycleUnavailableError("Player is not initialized or has been disposed")
   }
 
   private func mpvError(_ status: CInt) -> NSError {

shared/apple/MpvPlayer/MpvPlayerPluginShared.swift

@@ -49,11 +49,15 @@ extension MpvPluginShared {
           self?.didSetPauseProperty(value: value)
         }
         result(nil)
-      case .failure:
+      case .failure(let error):
+        let lifecycleUnavailable = error is MpvLifecycleUnavailableError
         result(
           FlutterError(
-            code: "SET_PROPERTY_FAILED",
-            message: "MPV rejected or cancelled the property write",
+            code: lifecycleUnavailable ? "NOT_INITIALIZED" : "SET_PROPERTY_FAILED",
+            message:
+              lifecycleUnavailable
+              ? "MPV player is not initialized"
+              : "MPV rejected or cancelled the property write",
             details: nil))
       }
     }

shared/mpv/mpv_player_common.h

@@ -26,6 +26,10 @@ static constexpr size_t kSetPropertyErrorDescriptionLimit = 160;
 
 inline bool SetPropertyStatusSucceeded(int status) { return status >= 0; }
 
+inline const char* SetPropertyErrorCode(int status) {
+  return status == MPV_ERROR_UNINITIALIZED ? kSetPropertyNotInitializedCode : kSetPropertyFailedCode;
+}
+
 inline std::string SetPropertyErrorDescription(int status) {
   const char* description = mpv_error_string(status);
   if (!description || description[0] == '\0') {

shared/mpv/mpv_player_common_test.cpp

@@ -81,14 +81,27 @@ void TestSetPropertyResultContract() {
   assert(SetPropertyStatusSucceeded(MPV_ERROR_SUCCESS));
   assert(SetPropertyStatusSucceeded(1));
 
-  constexpr int kFailureStatuses[] = {
+  assert(!SetPropertyStatusSucceeded(MPV_ERROR_UNINITIALIZED));
+
+  assert(std::string(SetPropertyErrorCode(MPV_ERROR_UNINITIALIZED)) == kSetPropertyNotInitializedCode);
+
+  constexpr int kRejectedStatuses[] = {
+      MPV_ERROR_INVALID_PARAMETER,
+      MPV_ERROR_PROPERTY_ERROR,
+      -1,
+  };
+  for (const int status : kRejectedStatuses) {
+    assert(!SetPropertyStatusSucceeded(status));
+    assert(std::string(SetPropertyErrorCode(status)) == kSetPropertyFailedCode);
+  }
+
+  constexpr int kDescribedStatuses[] = {
       MPV_ERROR_INVALID_PARAMETER,
       MPV_ERROR_PROPERTY_ERROR,
       -1,
       MPV_ERROR_UNINITIALIZED,
   };
-  for (const int status : kFailureStatuses) {
-    assert(!SetPropertyStatusSucceeded(status));
+  for (const int status : kDescribedStatuses) {
     const std::string description = SetPropertyErrorDescription(status);
     assert(!description.empty());
     assert(description.size() <= kSetPropertyErrorDescriptionLimit);