From 90ec40166fcb7a8ba78bc9ad9e70184b8e0df05c Mon Sep 17 00:00:00 2001
From: Vanilagy <1696106+Vanilagy@users.noreply.github.com>
Date: Wed, 29 Jul 2026 11:42:14 +0200
Subject: [PATCH] Fix decoders not being closed in certain error scenarios,
 fixed unsettled promises in reading logic (fixes #446)

---
 src/media-sink.ts | 16 +++++++++++-----
 src/source.ts     | 28 +++++++++++++++++++++++-----
 2 files changed, 34 insertions(+), 10 deletions(-)

diff --git a/src/media-sink.ts b/src/media-sink.ts
index 9a57bb6..aa80639 100644
--- a/src/media-sink.ts
+++ b/src/media-sink.ts
@@ -471,6 +471,7 @@ export abstract class BaseMediaSampleSink<
 		let decoderIsFlushed = false;
 		let ended = false;
 		let terminated = false;
+		let decoder: DecoderWrapper<MediaSample> | null = null;
 
 		// This stores errors that are "out of band" in the sense that they didn't occur in the normal flow of this
 		// method but instead in a different context. This error should not go unnoticed and must be bubbled up to
@@ -486,7 +487,7 @@ export abstract class BaseMediaSampleSink<
 
 		// The following is the "pump" process that keeps pumping packets into the decoder
 		(async () => {
-			const decoder = await this._createDecoder((sample) => {
+			decoder = await this._createDecoder((sample) => {
 				onQueueDequeue();
 				if (sample.timestamp >= endTimestamp) {
 					ended = true;
@@ -569,20 +570,21 @@ export abstract class BaseMediaSampleSink<
 			if (!terminated && !this._track.input._disposed) {
 				await decoder.flush();
 			}
-			decoder.close();
 
 			if (!firstSampleQueued && lastSample) {
 				sampleQueue.push(lastSample);
 			}
 
 			decoderIsFlushed = true;
-			onQueueNotEmpty(); // To unstuck the generator
+			onQueueNotEmpty(); // To unstuck (unstick?) the generator
 		})().catch((error) => {
 			if (!hasOutOfBandError) {
 				outOfBandError = error;
 				hasOutOfBandError = true;
 				onQueueNotEmpty();
 			}
+		}).finally(() => {
+			decoder?.close();
 		});
 
 		const track = this._track;
@@ -647,6 +649,7 @@ export abstract class BaseMediaSampleSink<
 		let { promise: queueDequeue, resolve: onQueueDequeue } = promiseWithResolvers();
 		let decoderIsFlushed = false;
 		let terminated = false;
+		let decoder: DecoderWrapper<MediaSample> | null = null;
 
 		// This stores errors that are "out of band" in the sense that they didn't occur in the normal flow of this
 		// method but instead in a different context. This error should not go unnoticed and must be bubbled up to
@@ -668,7 +671,7 @@ export abstract class BaseMediaSampleSink<
 
 		// The following is the "pump" process that keeps pumping packets into the decoder
 		(async () => {
-			const decoder = await this._createDecoder((sample) => {
+			decoder = await this._createDecoder((sample) => {
 				onQueueDequeue();
 
 				if (terminated) {
@@ -711,6 +714,7 @@ export abstract class BaseMediaSampleSink<
 
 			const decodePackets = async () => {
 				assert(lastKeyPacket);
+				assert(decoder);
 
 				// Start at the current key packet
 				let currentPacket = lastKeyPacket;
@@ -738,6 +742,7 @@ export abstract class BaseMediaSampleSink<
 			};
 
 			const flushDecoder = async () => {
+				assert(decoder);
 				await decoder.flush();
 
 				// We don't expect this list to have any elements in it anymore, but in case it does, let's emit
@@ -796,7 +801,6 @@ export abstract class BaseMediaSampleSink<
 
 				await flushDecoder();
 			}
-			decoder.close();
 
 			decoderIsFlushed = true;
 			onQueueNotEmpty(); // To unstuck the generator
@@ -806,6 +810,8 @@ export abstract class BaseMediaSampleSink<
 				hasOutOfBandError = true;
 				onQueueNotEmpty();
 			}
+		}).finally(() => {
+			decoder?.close();
 		});
 
 		const track = this._track;
diff --git a/src/source.ts b/src/source.ts
index 4192d9b..cfa7cdb 100644
--- a/src/source.ts
+++ b/src/source.ts
@@ -1665,6 +1665,10 @@ export class ReadableStreamSource extends Source {
 
 	/** @internal */
 	_dispose() {
+		for (const pendingSlice of this._pendingSlices) {
+			pendingSlice.reject(new InputDisposedError());
+		}
+
 		this._pendingSlices.length = 0;
 		this._cache.length = 0;
 		void this._reader?.cancel();
@@ -2328,11 +2332,13 @@ class ReadOrchestrator {
 	signalWorkerStoppedRunning(worker: ReadWorker) {
 		worker.running = false;
 
-		// When a worker stops running, that means it has hit its targetPos. It might still have pendingSlices assigned,
-		// but this is because those pending slices cover data that other workers are assigned to fill. Since targetPos
-		// has been reached, we can confidently say that this worker has completed its share of work on the pending
-		// slices and must no longer care about them.
-		worker.pendingSlices.length = 0;
+		if (!worker.aborted) {
+			// When a worker stops running, that means it has hit its targetPos. It might still have pendingSlices
+			// assigned, but this is because those pending slices cover data that other workers are assigned to fill.
+			// Since targetPos has been reached, we can confidently say that this worker has completed its share of work
+			// on the pending slices and must no longer care about them.
+			worker.pendingSlices.length = 0;
+		}
 	}
 
 	/** Called when a worker reaches the end of the underlying data and must be cleaned up. */
@@ -2447,11 +2453,23 @@ class ReadOrchestrator {
 
 	dispose() {
 		for (const worker of this.workers) {
+			for (const slice of worker.pendingSlices) {
+				slice.reject(new InputDisposedError());
+			}
+
+			worker.pendingSlices.length = 0;
 			worker.aborted = true;
 		}
 
+		for (const queuedRead of this.queuedReads) {
+			for (const slice of queuedRead.pendingSlices) {
+				slice.reject(new InputDisposedError());
+			}
+		}
+
 		this.workers.length = 0;
 		this.cache.length = 0;
+		this.queuedReads.length = 0;
 		this.disposed = true;
 	}
 }