fix(YouTube): Always use single threaded layout to resolve layout bugs in unpatched YouTube (#5226)

extensions/youtube/src/main/java/app/revanced/extension/youtube/patches/components/LithoFilterPatch.java

@@ -74,6 +74,29 @@ public final class LithoFilterPatch {
         }
     }
 
+    /**
+     * Litho layout fixed thread pool size override.
+     * <p>
+     * Unpatched YouTube uses a layout fixed thread pool between 1 and 3 threads:
+     * <pre>
+     * 1 thread - > Device has less than 6 cores
+     * 2 threads -> Device has over 6 cores and less than 6GB of memory
+     * 3 threads -> Device has over 6 cores and more than 6GB of memory
+     * </pre>
+     *
+     * Using more than 1 thread causes layout issues such as the You tab watch/playlist shelf
+     * that is sometimes incorrectly hidden (ReVanced is not hiding it), and seems to
+     * fix a race issue if using the active navigation tab status with litho filtering.
+     */
+    private static final int LITHO_LAYOUT_THREAD_POOL_SIZE = 1;
+
+    private static final byte[] EMPTY_BYTE_ARRAY = new byte[0];
+
+    /**
+     * Placeholder for actual filters.
+     */
+    private static final class DummyFilter extends Filter { }
+
     private static final Filter[] filters = new Filter[] {
             new DummyFilter() // Replaced by patch.
     };
@@ -81,8 +104,6 @@ public final class LithoFilterPatch {
     private static final StringTrieSearch pathSearchTree = new StringTrieSearch();
     private static final StringTrieSearch identifierSearchTree = new StringTrieSearch();
 
-    private static final byte[] EMPTY_BYTE_ARRAY = new byte[0];
-
     /**
      * Because litho filtering is multi-threaded and the buffer is passed in from a different injection point,
      * the buffer is saved to a ThreadLocal so each calling thread does not interfere with other threads.
@@ -213,9 +234,28 @@ public final class LithoFilterPatch {
 
         return false;
     }
-}
 
-/**
- * Placeholder for actual filters.
- */
-final class DummyFilter extends Filter { }
+    /**
+     * Injection point.
+     */
+    public static int getExecutorCorePoolSize(int originalCorePoolSize) {
+        if (originalCorePoolSize != LITHO_LAYOUT_THREAD_POOL_SIZE) {
+            Logger.printDebug(() -> "Overriding core thread pool size from: " + originalCorePoolSize
+                    + " to: " + LITHO_LAYOUT_THREAD_POOL_SIZE);
+        }
+
+        return LITHO_LAYOUT_THREAD_POOL_SIZE;
+    }
+
+    /**
+     * Injection point.
+     */
+    public static int getExecutorMaxThreads(int originalMaxThreads) {
+        if (originalMaxThreads != LITHO_LAYOUT_THREAD_POOL_SIZE) {
+            Logger.printDebug(() -> "Overriding max thread pool size from: " + originalMaxThreads
+                    + " to: " + LITHO_LAYOUT_THREAD_POOL_SIZE);
+        }
+
+        return LITHO_LAYOUT_THREAD_POOL_SIZE;
+    }
+}

patches/src/main/kotlin/app/revanced/patches/youtube/misc/litho/filter/Fingerprints.kt

@@ -1,6 +1,7 @@
 package app.revanced.patches.youtube.misc.litho.filter
 
 import app.revanced.patcher.fingerprint
+import app.revanced.util.containsLiteralInstruction
 import app.revanced.util.literal
 import com.android.tools.smali.dexlib2.AccessFlags
 import com.android.tools.smali.dexlib2.Opcode
@@ -52,6 +53,15 @@ internal val emptyComponentFingerprint = fingerprint {
     }
 }
 
+internal val lithoThreadExecutorFingerprint = fingerprint {
+    accessFlags(AccessFlags.PUBLIC, AccessFlags.CONSTRUCTOR)
+    parameters("I", "I", "I")
+    custom { method, classDef ->
+        classDef.superclass == "Ljava/util/concurrent/ThreadPoolExecutor;" &&
+            method.containsLiteralInstruction(1L) // 1L = default thread timeout.
+    }
+}
+
 internal val lithoComponentNameUpbFeatureFlagFingerprint = fingerprint {
     accessFlags(AccessFlags.PUBLIC, AccessFlags.FINAL)
     returns("Z")

patches/src/main/kotlin/app/revanced/patches/youtube/misc/litho/filter/LithoFilterPatch.kt

@@ -209,6 +209,22 @@ val lithoFilterPatch = bytecodePatch(
 
         // endregion
 
+
+        // region Change Litho thread executor to 1 thread to fix layout issue in unpatched YouTube.
+
+        lithoThreadExecutorFingerprint.method.addInstructions(
+            0,
+            """
+                invoke-static { p1 }, $EXTENSION_CLASS_DESCRIPTOR->getExecutorCorePoolSize(I)I
+                move-result p1
+                invoke-static { p2 }, $EXTENSION_CLASS_DESCRIPTOR->getExecutorMaxThreads(I)I
+                move-result p2
+            """
+        )
+
+        // endregion
+
+
         // region A/B test of new Litho native code.
 
         // Turn off native code that handles litho component names.  If this feature is on then nearly