CrashTracer: com.apple.WebKit.GPU at AVFCore: -[AVPlayerItem _seekToT…

…ime:toleranceBefore:toleranceAfter:seekID:completionHandler:]

https://bugs.webkit.org/show_bug.cgi?id=243068
<rdar://95237949>

Reviewed by Jer Noble.

AVPlayerItem throws an exception when an invalid or negative tolerance value
is passed to the -seekToTime: method. If we run into a bad tolerance value,
we can just ignore the tolerance by setting it to positive infinity.

From the AVF documentation: (https://developer.apple.com/documentation/avfoundation/avplayer/1388493-seektotime)
Invoking this method with toleranceBefore set to kCMTimePositiveInfinity
and toleranceAfter set to kCMTimePositiveInfinity is the same as invoking seekToTime:.

* Source/WebCore/html/HTMLMediaElement.cpp:
(WebCore::HTMLMediaElement::seekTask):
* Source/WebCore/platform/graphics/avfoundation/objc/MediaPlayerPrivateAVFoundationObjC.mm:
(WebCore::MediaPlayerPrivateAVFoundationObjC::seekToTime):

Canonical link: https://commits.webkit.org/252714@main

Source/WebCore/html/HTMLMediaElement.cpp

@@ -3228,7 +3228,10 @@ void HTMLMediaElement::seekTask()
     MediaTime positiveTolerance = m_pendingSeek->positiveTolerance;
     m_pendingSeek = nullptr;
 
+    ASSERT(negativeTolerance.isValid());
     ASSERT(negativeTolerance >= MediaTime::zeroTime());
+    ASSERT(positiveTolerance.isValid());
+    ASSERT(positiveTolerance >= MediaTime::zeroTime());
 
     // 6 - If the new playback position is later than the end of the media resource, then let it be the end
     // of the media resource instead.

Source/WebCore/platform/graphics/avfoundation/objc/MediaPlayerPrivateAVFoundationObjC.mm

@@ -1557,6 +1557,8 @@ static URL conformFragmentIdentifierForURL(const URL& url)
 
 void MediaPlayerPrivateAVFoundationObjC::seekToTime(const MediaTime& time, const MediaTime& negativeTolerance, const MediaTime& positiveTolerance)
 {
+    ASSERT(time.isFinite());
+
     // setCurrentTime generates several event callbacks, update afterwards.
     setDelayCallbacks(true);
 
@@ -1567,9 +1569,11 @@ static URL conformFragmentIdentifierForURL(const URL& url)
     CMTime cmBefore = PAL::toCMTime(negativeTolerance);
     CMTime cmAfter = PAL::toCMTime(positiveTolerance);
 
-    // [AVPlayerItem seekToTime] will throw an exception if toleranceBefore is negative.
-    if (PAL::CMTimeCompare(cmBefore, PAL::kCMTimeZero) < 0)
-        cmBefore = PAL::kCMTimeZero;
+    // [AVPlayerItem seekToTime] will throw an exception if a tolerance is invalid or negative.
+    if (!CMTIME_IS_VALID(cmBefore) || PAL::CMTimeCompare(cmBefore, PAL::kCMTimeZero) < 0)
+        cmBefore = PAL::kCMTimePositiveInfinity;
+    if (!CMTIME_IS_VALID(cmAfter) || PAL::CMTimeCompare(cmAfter, PAL::kCMTimeZero) < 0)
+        cmAfter = PAL::kCMTimePositiveInfinity;
 
     WeakPtr weakThis { *this };