Avoid uninitialized memory when decomposing a matrix fails.

Source/platform/transforms/RotateTransformOperation.cpp

 /*
  * Copyright (C) 1999 Antti Koivisto (koivisto@kde.org)
  * Copyright (C) 2004, 2005, 2006, 2007, 2008 Apple Inc. All rights reserved.
  *
  * This library is free software; you can redistribute it and/or
  * modify it under the terms of the GNU Library General Public
  * License as published by the Free Software Foundation; either
  * version 2 of the License, or (at your option) any later version.
  *
  * This library is distributed in the hope that it will be useful,
@@ skipping 109 matching lines @@
     toT.rotate3d((toOp ? toOp->m_x : 0),
         (toOp ? toOp->m_y : 0),
         (toOp ? toOp->m_z : 1),
         (toOp ? toOp->m_angle : 0));
 
     // Blend them
     toT.blend(fromT, progress);
 
     // Extract the result as a quaternion
     TransformationMatrix::DecomposedType decomp;
-    toT.decompose(decomp);
+    if (!toT.decompose(decomp)) {
+        // If we can't decompose, bail out of interpolation.
+        const RotateTransformOperation* usedOperation = progress > 0.5 ? this : fromOp;
+        return RotateTransformOperation::create(usedOperation->x(), usedOperation->y(), usedOperation->z(), usedOperation->angle(), Rotate3D);
+    }
 
     // Convert that to Axis/Angle form
     double x = -decomp.quaternionX;
     double y = -decomp.quaternionY;
     double z = -decomp.quaternionZ;
     double length = std::sqrt(x * x + y * y + z * z);
     double angle = 0;
 
     if (length > 0.00001) {
         x /= length;
         y /= length;
         z /= length;
         angle = rad2deg(std::acos(decomp.quaternionW) * 2);
     } else {
         x = 0;
         y = 0;
         z = 1;
     }
     return RotateTransformOperation::create(x, y, z, angle, Rotate3D);
 }
 
 bool RotateTransformOperation::canBlendWith(const TransformOperation& other) const
 {
     return other.isSameType(*this);
 }
 
 } // namespace blink