fix(YouTube): When clicking on timestamps in comments, playback speed sometimes changes to 1.0x (unpatched YouTube bug)

patches/src/main/kotlin/app/revanced/patches/youtube/utils/fix/playbackspeed/Fingerprints.kt

@@ -0,0 +1,42 @@
+package app.revanced.patches.youtube.utils.fix.playbackspeed
+
+import app.revanced.util.fingerprint.legacyFingerprint
+import app.revanced.util.getReference
+import app.revanced.util.indexOfFirstInstructionReversed
+import app.revanced.util.or
+import com.android.tools.smali.dexlib2.AccessFlags
+import com.android.tools.smali.dexlib2.Opcode
+import com.android.tools.smali.dexlib2.iface.Method
+import com.android.tools.smali.dexlib2.iface.reference.FieldReference
+
+/**
+ * This fingerprint is compatible with YouTube 17.34.36 ~ 19.50.40.
+ *
+ * This method is usually used to set the initial speed (1.0x) when playback starts from the feed.
+ * For some reason, in the latest YouTube, it is invoked even after the video has already started.
+ */
+internal val playbackSpeedInFeedsFingerprint = legacyFingerprint(
+    name = "playbackSpeedInFeedsFingerprint",
+    returnType = "V",
+    accessFlags = AccessFlags.PUBLIC or AccessFlags.FINAL,
+    parameters = listOf("L"),
+    opcodes = listOf(
+        Opcode.IGET,
+        Opcode.MUL_INT_LIT16,
+        Opcode.IGET_WIDE,
+        Opcode.CONST_WIDE_16,
+        Opcode.CMP_LONG,
+        Opcode.IF_EQZ,
+        Opcode.IF_LEZ,
+        Opcode.SUB_LONG_2ADDR,
+    ),
+    customFingerprint = { method, _ ->
+        indexOfGetPlaybackSpeedInstruction(method) >= 0
+    }
+)
+
+fun indexOfGetPlaybackSpeedInstruction(method: Method) =
+    method.indexOfFirstInstructionReversed {
+        opcode == Opcode.IGET &&
+                getReference<FieldReference>()?.type == "F"
+    }

patches/src/main/kotlin/app/revanced/patches/youtube/utils/fix/playbackspeed/PlaybackSpeedWhilePlayingPatch.kt

@@ -0,0 +1,60 @@
+package app.revanced.patches.youtube.utils.fix.playbackspeed
+
+import app.revanced.patcher.extensions.InstructionExtensions.addInstructionsWithLabels
+import app.revanced.patcher.extensions.InstructionExtensions.getInstruction
+import app.revanced.patcher.patch.bytecodePatch
+import app.revanced.patcher.util.smali.ExternalLabel
+import app.revanced.patches.youtube.utils.extension.Constants.UTILS_PATH
+import app.revanced.patches.youtube.utils.extension.sharedExtensionPatch
+import app.revanced.patches.youtube.utils.playertype.playerTypeHookPatch
+import app.revanced.patches.youtube.utils.playservice.is_19_34_or_greater
+import app.revanced.patches.youtube.utils.playservice.versionCheckPatch
+import app.revanced.util.fingerprint.methodOrThrow
+import app.revanced.util.indexOfFirstInstructionOrThrow
+import com.android.tools.smali.dexlib2.Opcode
+import com.android.tools.smali.dexlib2.iface.instruction.TwoRegisterInstruction
+
+private const val EXTENSION_CLASS_DESCRIPTOR =
+    "$UTILS_PATH/PlaybackSpeedWhilePlayingPatch;"
+
+val playbackSpeedWhilePlayingPatch = bytecodePatch(
+    description = "playbackSpeedWhilePlayingPatch"
+) {
+    dependsOn(
+        sharedExtensionPatch,
+        playerTypeHookPatch,
+        versionCheckPatch,
+    )
+
+    execute {
+        if (!is_19_34_or_greater) {
+            return@execute
+        }
+
+        /**
+         * There is an issue where sometimes when you click on a comment in a video and press the back button or click on the timestamp of the comment, the playback speed will change to 1.0x.
+         *
+         * This can be reproduced on unpatched YouTube 19.34.42+ by following these steps:
+         * 1. After the video starts, manually change the playback speed to something other than 1.0x.
+         * 2. If enough time has passed since the video started, open the comments panel.
+         * 3. Click on a comment and press the back button, or click on the timestamp of the comment.
+         * 4. Sometimes the playback speed will change to 1.0x.
+         *
+         * This is an issue that Google should fix, but it is not that hard to fix, so it has been implemented in the patch.
+         */
+        playbackSpeedInFeedsFingerprint.methodOrThrow().apply {
+            val freeRegister = implementation!!.registerCount - parameters.size - 2
+            val playbackSpeedIndex = indexOfGetPlaybackSpeedInstruction(this)
+            val playbackSpeedRegister = getInstruction<TwoRegisterInstruction>(playbackSpeedIndex).registerA
+            val jumpIndex = indexOfFirstInstructionOrThrow(playbackSpeedIndex, Opcode.RETURN_VOID)
+
+            addInstructionsWithLabels(
+                playbackSpeedIndex + 1, """
+                    invoke-static { v$playbackSpeedRegister }, $EXTENSION_CLASS_DESCRIPTOR->playbackSpeedChanged(F)Z
+                    move-result v$freeRegister
+                    if-nez v$freeRegister, :do_not_change
+                    """, ExternalLabel("do_not_change", getInstruction(jumpIndex))
+            )
+        }
+    }
+}

patches/src/main/kotlin/app/revanced/patches/youtube/utils/settings/SettingsPatch.kt

@@ -15,6 +15,7 @@ import app.revanced.patches.youtube.utils.compatibility.Constants.COMPATIBLE_PAC
 import app.revanced.patches.youtube.utils.extension.Constants.UTILS_PATH
 import app.revanced.patches.youtube.utils.extension.sharedExtensionPatch
 import app.revanced.patches.youtube.utils.fix.cairo.cairoSettingsPatch
+import app.revanced.patches.youtube.utils.fix.playbackspeed.playbackSpeedWhilePlayingPatch
 import app.revanced.patches.youtube.utils.fix.splash.darkModeSplashScreenPatch
 import app.revanced.patches.youtube.utils.mainactivity.mainActivityResolvePatch
 import app.revanced.patches.youtube.utils.patch.PatchList.SETTINGS_FOR_YOUTUBE
@@ -122,6 +123,7 @@ val settingsPatch = resourcePatch(
         settingsBytecodePatch,
         cairoSettingsPatch,
         darkModeSplashScreenPatch,
+        playbackSpeedWhilePlayingPatch,
     )
 
     val insertPosition = stringOption(