From 3999685f8c5b4f805a47033e7762da7b984942a4 Mon Sep 17 00:00:00 2001
From: Gary Tokman <yo@garytokman.com>
Date: Fri, 16 Oct 2026 13:19:46 -0400
Subject: [PATCH] Avoid isolated deinit for synchronous Markdown rendering
 helpers

---
 .../MarkdownTextBuilder/ListProcessor.swift   |  3 ++
 .../Supplements/InlineNode+Render.swift       |  3 ++
 .../RenderingLifetimeTests.swift              | 49 +++++++++++++++++++
 3 files changed, 55 insertions(+)
 create mode 100644 Tests/MarkdownViewTests/RenderingLifetimeTests.swift

diff --git a/Sources/MarkdownView/MarkdownTextBuilder/ListProcessor.swift b/Sources/MarkdownView/MarkdownTextBuilder/ListProcessor.swift
index 15fee45..a4408f7 100644
--- a/Sources/MarkdownView/MarkdownTextBuilder/ListProcessor.swift
+++ b/Sources/MarkdownView/MarkdownTextBuilder/ListProcessor.swift
@@ -15,6 +15,9 @@ import MarkdownParser
 // MARK: - ListProcessor
 
 final class ListProcessor {
+    // Synchronous rendering must avoid the isolated-deinit back-deployment path.
+    nonisolated deinit {}
+
     private let theme: MarkdownTheme
     private let context: MarkdownTextView.PreprocessedContent
     private let viewProvider: ReusableViewProvider
diff --git a/Sources/MarkdownView/Supplements/InlineNode+Render.swift b/Sources/MarkdownView/Supplements/InlineNode+Render.swift
index 2b021fe..198792b 100644
--- a/Sources/MarkdownView/Supplements/InlineNode+Render.swift
+++ b/Sources/MarkdownView/Supplements/InlineNode+Render.swift
@@ -18,6 +18,9 @@ import SwiftMath
 /// Cached attribute dictionaries to avoid repeated allocations.
 /// Keyed by theme identity (font + color) which changes infrequently.
 final class InlineAttributeCache {
+    // Synchronous rendering must avoid the isolated-deinit back-deployment path.
+    nonisolated deinit {}
+
     let bodyAttributes: [NSAttributedString.Key: Any]
     let codeAttributes: [NSAttributedString.Key: Any]
 
diff --git a/Tests/MarkdownViewTests/RenderingLifetimeTests.swift b/Tests/MarkdownViewTests/RenderingLifetimeTests.swift
new file mode 100644
index 0000000..6a71558
--- /dev/null
+++ b/Tests/MarkdownViewTests/RenderingLifetimeTests.swift
@@ -0,0 +1,49 @@
+import Foundation
+import XCTest
+@testable import MarkdownView
+
+@MainActor
+final class RenderingLifetimeTests: XCTestCase {
+    private enum LayoutContext {
+        @TaskLocal static var value = "outside"
+    }
+
+    func testInlineAttributeCacheReleaseInsideSynchronousTaskLocalScope() {
+        checkSynchronousRelease {
+            InlineAttributeCache(theme: .default)
+        }
+    }
+
+    func testListProcessorAndOwnedCacheReleaseInsideSynchronousTaskLocalScope() {
+        let theme = MarkdownTheme.default
+        let context = MarkdownTextView.PreprocessedContent(markdown: "- **First**\n- `Second`", theme: theme)
+        let viewProvider = ReusableViewProvider()
+        checkSynchronousRelease {
+            ListProcessor(
+                theme: theme,
+                viewProvider: viewProvider,
+                context: context,
+                bulletDrawing: nil,
+                numberedDrawing: nil,
+                checkboxDrawing: nil
+            )
+        }
+    }
+
+    // Keep this synchronous to match UIKit layout callbacks outside a Swift task.
+    private func checkSynchronousRelease<T: AnyObject>(_ makeObject: () -> T) {
+        for _ in 0 ..< 100 {
+            LayoutContext.$value.withValue("layout") {
+                autoreleasepool {
+                    var objects = [0: makeObject()]
+                    weak var object: T?
+                    object = objects[0]
+                    objects.removeAll()
+                    XCTAssertNil(object)
+                }
+                XCTAssertEqual(LayoutContext.value, "layout")
+            }
+            XCTAssertEqual(LayoutContext.value, "outside")
+        }
+    }
+}