diff --git a/Source/WebCore/ChangeLog b/Source/WebCore/ChangeLog
index 5be2957..9894fd2 100644
--- a/Source/WebCore/ChangeLog
+++ b/Source/WebCore/ChangeLog
@@ -1,3 +1,22 @@
+2019-10-16  Brent Fulgham  <bfulgham@apple.com>
+
+        [FTW] Correct radial gradient handling of various radius orderings
+        https://bugs.webkit.org/show_bug.cgi?id=202815
+
+        Reviewed by Per Arne Vollan.
+
+        Revise the 'generateGradient' implementation to recognize that the
+        radius arguments might not be in increasing order. Direct2D's
+        implementation does expect this, so we need to swap order and
+        revise the gradient range to match.
+
+        Drive-by fix: Stop building unused image decoders if building with
+        the Apple stack.
+
+        * PlatformFTW.cmake: Stop building unused image decoders.
+        * platform/graphics/win/GradientDirect2D.cpp:
+        (WebCore::Gradient::generateGradient):
+
 2019-10-16  Chris Dumez  <cdumez@apple.com>
 
         Rename PageCache to BackForwardCache
diff --git a/Source/WebCore/PlatformFTW.cmake b/Source/WebCore/PlatformFTW.cmake
index e674a19..791d97b 100644
--- a/Source/WebCore/PlatformFTW.cmake
+++ b/Source/WebCore/PlatformFTW.cmake
@@ -1,5 +1,7 @@
 include(platform/Curl.cmake)
-include(platform/ImageDecoders.cmake)
+if (NOT APPLE_BUILD)
+    include(platform/ImageDecoders.cmake)
+endif ()
 include(platform/TextureMapper.cmake)
 
 list(APPEND WebCore_PRIVATE_INCLUDE_DIRECTORIES
diff --git a/Source/WebCore/platform/graphics/win/GradientDirect2D.cpp b/Source/WebCore/platform/graphics/win/GradientDirect2D.cpp
index fcb173f..89096f4 100644
--- a/Source/WebCore/platform/graphics/win/GradientDirect2D.cpp
+++ b/Source/WebCore/platform/graphics/win/GradientDirect2D.cpp
@@ -1,5 +1,5 @@
 /*
- * Copyright (C) 2016-2018 Apple Inc.  All rights reserved.
+ * Copyright (C) 2016-2019 Apple Inc.  All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions
@@ -56,6 +56,15 @@
     return m_gradient;
 }
 
+static bool circleIsEntirelyContained(const FloatPoint& centerA, float radiusA, const FloatPoint& centerB, float radiusB)
+{
+    double deltaX = centerB.x() - centerA.x();
+    double deltaY = centerB.y() - centerA.y();
+    double deltaRadius = radiusB - radiusA;
+
+    return deltaX * deltaX + deltaY * deltaY < deltaRadius * deltaRadius && radiusA < radiusB;
+}
+
 void Gradient::generateGradient(ID2D1RenderTarget* renderTarget)
 {
     sortStopsIfNecessary();
@@ -75,11 +84,23 @@
         [&] (const LinearData&) {
             // No action needed.
         },
-        [&] (const RadialData& data) {
-            if (data.startRadius && data.endRadius) {
-                float startPosition = std::abs(data.startRadius / data.endRadius);
-                if (startPosition > 1.0)
-                    startPosition = 1.0 / startPosition;
+        [&] (RadialData& data) {
+            RELEASE_ASSERT(data.startRadius >= 0);
+            RELEASE_ASSERT(data.endRadius >= 0);
+
+            if (data.startRadius > data.endRadius) {
+                gradientStops.reverse();
+                for (auto& stop : gradientStops)
+                    stop.position = 1.0 - stop.position;
+
+                std::swap(data.startRadius, data.endRadius);
+                std::swap(data.point0, data.point1);
+            }
+
+            if (data.startRadius) {
+                RELEASE_ASSERT(data.endRadius > 0);
+                float startPosition = data.startRadius / data.endRadius;
+                RELEASE_ASSERT(startPosition <= 1.0);
                 float availableRange = 1.0 - startPosition;
                 RELEASE_ASSERT(availableRange <= 1.0 && availableRange >= 0);
 
@@ -90,9 +111,10 @@
 
                 // Restore the 'start' position
                 auto firstStop = gradientStops.first();
-                firstStop.position = 0;
-
-                gradientStops.insert(0, firstStop);
+                if (!WTF::areEssentiallyEqual(firstStop.position, 0.0f)) {
+                    firstStop.position = 0;
+                    gradientStops.insert(0, firstStop);
+                }
             }
         },
         [&] (const ConicData&) {
@@ -120,7 +142,12 @@
             m_gradient = linearGradient;
         },
         [&] (const RadialData& data) {
-            FloatSize offset = data.point0 - data.point1;
+            FloatSize offset;
+            if (!circleIsEntirelyContained(data.point0, data.startRadius, data.point1, data.endRadius))
+                offset = (data.point1.scaled(data.startRadius) - data.point0.scaled(data.endRadius)) / (data.endRadius - data.startRadius);
+            else
+                offset = data.point0 - data.point1;
+
             FloatPoint center = data.point1;
             float radiusX = data.endRadius;
             float radiusY = radiusX / data.aspectRatio;