A MediaTime timescale must never be zero

https://bugs.webkit.org/show_bug.cgi?id=193156
<rdar://problem/32504501>

Reviewed by Jer Noble.

Source/WTF:

* wtf/MediaTime.cpp:
(WTF::greatestCommonDivisor): ASSERT if either parameter or return value is zero.
(WTF::MediaTime::MediaTime): Create +/- infinity if passed zero timescale.
(WTF::MediaTime::createWithFloat): Ditto.
(WTF::MediaTime::createWithDouble): Ditto.
(WTF::MediaTime::setTimeScale): Ditto.

Tools:

* TestWebKitAPI/Tests/WTF/MediaTime.cpp:
(TestWebKitAPI::TEST): Add tests for zero timescale.

git-svn-id: https://svn.webkit.org/repository/webkit/trunk@239688 268f45cc-cd09-0410-ab3c-d52691b4dbfc

diff --git a/Source/WTF/ChangeLog b/Source/WTF/ChangeLog
index 9de0c6b..48cfa46 100644 (file)
--- a/Source/WTF/ChangeLog
+++ b/Source/WTF/ChangeLog
@@ -1,3 +1,18 @@
+2019-01-07  Eric Carlson  <eric.carlson@apple.com>
+
+        A MediaTime timescale must never be zero
+        https://bugs.webkit.org/show_bug.cgi?id=193156
+        <rdar://problem/32504501>
+
+        Reviewed by Jer Noble.
+
+        * wtf/MediaTime.cpp:
+        (WTF::greatestCommonDivisor): ASSERT if either parameter or return value is zero.
+        (WTF::MediaTime::MediaTime): Create +/- infinity if passed zero timescale.
+        (WTF::MediaTime::createWithFloat): Ditto.
+        (WTF::MediaTime::createWithDouble): Ditto.
+        (WTF::MediaTime::setTimeScale): Ditto.
+
 2019-01-02  Alex Christensen  <achristensen@webkit.org>
 
         Homograph with LATIN SMALL LETTER R WITH FISHHOOK

diff --git a/Source/WTF/wtf/MediaTime.cpp b/Source/WTF/wtf/MediaTime.cpp
index 94712ea..417550c 100644 (file)
--- a/Source/WTF/wtf/MediaTime.cpp
+++ b/Source/WTF/wtf/MediaTime.cpp
@@ -1,5 +1,5 @@
 /*
- * Copyright (C) 2012 Apple Inc. All rights reserved.
+ * Copyright (C) 2012-2019 Apple Inc. All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions
@@ -31,6 +31,7 @@
 
 #include <algorithm>
 #include <cstdlib>
+#include <wtf/Assertions.h>
 #include <wtf/CheckedArithmetic.h>
 #include <wtf/JSONValues.h>
 #include <wtf/MathExtras.h>
@@ -41,6 +42,9 @@ namespace WTF {
 
 static uint32_t greatestCommonDivisor(uint32_t a, uint32_t b)
 {
+    ASSERT(a);
+    ASSERT(b);
+
     // Euclid's Algorithm
     uint32_t temp = 0;
     while (b) {
@@ -48,6 +52,8 @@ static uint32_t greatestCommonDivisor(uint32_t a, uint32_t b)
         b = a % b;
         a = temp;
     }
+
+    ASSERT(a);
     return a;
 }
 
@@ -75,6 +81,10 @@ MediaTime::MediaTime(int64_t value, uint32_t scale, uint8_t flags)
     , m_timeScale(scale)
     , m_timeFlags(flags)
 {
+    if (scale || isInvalid())
+        return;
+
+    *this = value < 0 ? negativeInfiniteTime() : positiveInfiniteTime();
 }
 
 MediaTime::~MediaTime()
@@ -108,6 +118,8 @@ MediaTime MediaTime::createWithFloat(float floatTime, uint32_t timeScale)
         return positiveInfiniteTime();
     if (floatTime < std::numeric_limits<int64_t>::min())
         return negativeInfiniteTime();
+    if (!timeScale)
+        return std::signbit(floatTime) ? negativeInfiniteTime() : positiveInfiniteTime();
 
     while (floatTime * timeScale > std::numeric_limits<int64_t>::max())
         timeScale /= 2;
@@ -136,6 +148,8 @@ MediaTime MediaTime::createWithDouble(double doubleTime, uint32_t timeScale)
         return positiveInfiniteTime();
     if (doubleTime < std::numeric_limits<int64_t>::min())
         return negativeInfiniteTime();
+    if (!timeScale)
+        return std::signbit(doubleTime) ? negativeInfiniteTime() : positiveInfiniteTime();
 
     while (doubleTime * timeScale > std::numeric_limits<int64_t>::max())
         timeScale /= 2;
@@ -484,6 +498,11 @@ void MediaTime::setTimeScale(uint32_t timeScale, RoundingFlags flags)
         return;
     }
 
+    if (!timeScale) {
+        *this = m_timeValue < 0 ? negativeInfiniteTime() : positiveInfiniteTime();
+        return;
+    }
+
     if (timeScale == m_timeScale)
         return;
 

diff --git a/Tools/ChangeLog b/Tools/ChangeLog
index be75265..d5fb0a3 100644 (file)
--- a/Tools/ChangeLog
+++ b/Tools/ChangeLog
@@ -1,3 +1,14 @@
+2019-01-07  Eric Carlson  <eric.carlson@apple.com>
+
+        A MediaTime timescale must never be zero
+        https://bugs.webkit.org/show_bug.cgi?id=193156
+        <rdar://problem/32504501>
+
+        Reviewed by Jer Noble.
+
+        * TestWebKitAPI/Tests/WTF/MediaTime.cpp:
+        (TestWebKitAPI::TEST): Add tests for zero timescale.
+
 2019-01-07  Youenn Fablet  <youenn@apple.com>
 
         API test broken: TestWebKitAPI.WebKit.CustomDataStorePathsVersusCompletionHandlers

diff --git a/Tools/TestWebKitAPI/Tests/WTF/MediaTime.cpp b/Tools/TestWebKitAPI/Tests/WTF/MediaTime.cpp
index 703ab12..961bc26 100644 (file)
--- a/Tools/TestWebKitAPI/Tests/WTF/MediaTime.cpp
+++ b/Tools/TestWebKitAPI/Tests/WTF/MediaTime.cpp
@@ -1,5 +1,5 @@
 /*
- * Copyright (C) 2012 Apple Inc. All rights reserved.
+ * Copyright (C) 2012-2019 Apple Inc. All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions
@@ -309,6 +309,18 @@ TEST(WTF, MediaTime)
     EXPECT_EQ(MediaTime(bigInt - 2, MediaTime::MaximumTimeScale).toTimeScale(MediaTime::MaximumTimeScale - 1).hasBeenRounded(), true);
     EXPECT_EQ(MediaTime(bigInt, 1).toTimeScale(MediaTime::MaximumTimeScale), MediaTime::positiveInfiniteTime());
     EXPECT_EQ(MediaTime(-bigInt, 1).toTimeScale(MediaTime::MaximumTimeScale), MediaTime::negativeInfiniteTime());
+
+    // Non-zero timescale
+    EXPECT_EQ(MediaTime(102, 0), MediaTime::positiveInfiniteTime());
+    EXPECT_EQ(MediaTime(-102, 0), MediaTime::negativeInfiniteTime());
+    EXPECT_EQ(MediaTime::createWithDouble(99, 0), MediaTime::positiveInfiniteTime());
+    EXPECT_EQ(MediaTime::createWithDouble(-99, 0), MediaTime::negativeInfiniteTime());
+    EXPECT_EQ(MediaTime::createWithDouble(99).toTimeScale(0), MediaTime::positiveInfiniteTime());
+    EXPECT_EQ(MediaTime::createWithDouble(-99).toTimeScale(0), MediaTime::negativeInfiniteTime());
+    EXPECT_EQ(MediaTime::createWithFloat(909, 0), MediaTime::positiveInfiniteTime());
+    EXPECT_EQ(MediaTime::createWithFloat(-909, 0), MediaTime::negativeInfiniteTime());
+    EXPECT_EQ(MediaTime::createWithFloat(999).toTimeScale(0), MediaTime::positiveInfiniteTime());
+    EXPECT_EQ(MediaTime::createWithFloat(-999).toTimeScale(0), MediaTime::negativeInfiniteTime());
 }
 
 }