diff --git a/Source/WebCore/ChangeLog b/Source/WebCore/ChangeLog
index 0fa873efcc7dbdcffd96833215531e35b8a51d78..ad88aa5552c7a0fb0aaa2b919e2e6fb69dd46b11 100644
--- a/Source/WebCore/ChangeLog
+++ b/Source/WebCore/ChangeLog
@@ -1,3 +1,21 @@
+2011-07-07  Dirk Schulze  <krit@webkit.org>
+
+        SVGAnimateTransform does not support calcMode=discrete
+        https://bugs.webkit.org/show_bug.cgi?id=63914
+
+        Reviewed by Rob Buis.
+
+        CalcMode discrete specifies that the animation function will jump from one value to the next without any interpolation.
+        Implemented calcMode discrete by checking current progress of animation. If we are in the first half of the animation,
+        we use the start value of the aniamtion, end value for the second half of the animation. The key time at 50% is used on
+        all other animations as well as on other SVG viewers.
+
+        Added a manual test. DRT crashes on an automated test with the SVG animation API. Opened a new bug report: 64104.
+
+        * manual-tests/svg-animateTransform-calcMode-discrete.svg: Added.
+        * svg/SVGAnimateTransformElement.cpp:
+        (WebCore::SVGAnimateTransformElement::calculateAnimatedValue):
+
 2011-07-07  Dirk Schulze  <krit@webkit.org>
 
         Reviewed by Rob Buis.
diff --git a/Source/WebCore/manual-tests/svg-animateTransform-calcMode-discrete.svg b/Source/WebCore/manual-tests/svg-animateTransform-calcMode-discrete.svg
new file mode 100644
index 0000000000000000000000000000000000000000..f9abef8e3240236be28f54379500547975d61d80
--- /dev/null
+++ b/Source/WebCore/manual-tests/svg-animateTransform-calcMode-discrete.svg
@@ -0,0 +1,6 @@
+<svg xmlns="http://www.w3.org/2000/svg">
+<text x="10" y="20">Testing calcMode="discrete" for &lt;animateTransform&gt;. The rect should jump by 100px at 2s.</text>
+<rect y="30" width="100px" height="100px" fill="green">
+    <animateTransform attributeName="transform" type="translate" from="0,0" to="100,0" calcMode="discrete" fill="freeze" dur="4s"/>
+</rect>
+</svg>
diff --git a/Source/WebCore/svg/SVGAnimateTransformElement.cpp b/Source/WebCore/svg/SVGAnimateTransformElement.cpp
index 1cfb48b91bb05d3fda33344ea877fe7a89c90a4a..2cdefca9abfa90575bee69846e64aa8f0d997276 100644
--- a/Source/WebCore/svg/SVGAnimateTransformElement.cpp
+++ b/Source/WebCore/svg/SVGAnimateTransformElement.cpp
@@ -158,6 +158,9 @@ void SVGAnimateTransformElement::calculateAnimatedValue(float percentage, unsign
         return;
     SVGTransformList* transformList = transformListFor(targetElement);
     ASSERT(transformList);
+    
+    if (calcMode() == CalcModeDiscrete)
+        percentage = percentage < 0.5 ? 0 : 1;
 
     if (!isAdditive())
         transformList->clear();