--- a/gfx/layers/wr/WebRenderCommandBuilder.cpp
+++ b/gfx/layers/wr/WebRenderCommandBuilder.cpp
@@ -2427,19 +2427,16 @@ Maybe<wr::ImageMask> WebRenderCommandBui
           aMaskItem, aBuilder.GetRenderRoot());
 
   if (!maskData) {
     return Nothing();
   }
 
   bool snap;
   nsRect bounds = aMaskItem->GetBounds(aDisplayListBuilder, &snap);
-  if (bounds.IsEmpty()) {
-    return Nothing();
-  }
 
   const int32_t appUnitsPerDevPixel =
       aMaskItem->Frame()->PresContext()->AppUnitsPerDevPixel();
 
   Size scale = aSc.GetInheritedScale();
   Size oldScale = maskData->mScale;
   // This scale determination should probably be done using
   // ChooseScaleAndSetTransform but for now we just fake it.
@@ -2447,16 +2444,20 @@ Maybe<wr::ImageMask> WebRenderCommandBui
   // rerasterize on MotionMark
   bool sameScale = FuzzyEqual(scale.width, oldScale.width, 1e-6f) &&
                    FuzzyEqual(scale.height, oldScale.height, 1e-6f);
 
   LayerIntRect itemRect =
       LayerIntRect::FromUnknownRect(bounds.ScaleToOutsidePixels(
           scale.width, scale.height, appUnitsPerDevPixel));
 
+  if (itemRect.IsEmpty()) {
+    return Nothing();
+  }
+
   LayoutDeviceToLayerScale2D layerScale(scale.width, scale.height);
   LayoutDeviceRect imageRect = LayerRect(itemRect) / layerScale;
 
   nsPoint maskOffset = aMaskItem->ToReferenceFrame() - bounds.TopLeft();
 
   nsRect dirtyRect;
   if (aMaskItem->IsInvalid(dirtyRect) ||
       !itemRect.IsEqualInterior(maskData->mItemRect) ||

--- a/layout/base/crashtests/crashtests.list
+++ b/layout/base/crashtests/crashtests.list
@@ -578,8 +578,9 @@ load 1553874.html
 load 1560328.html
 pref(layout.css.column-span.enabled,true) load 1566672.html
 load 1574101-1.html
 load 1574101-2.html
 HTTP load 1575908-1.html
 load 1576972-1.html
 pref(layout.css.column-span.enabled,true) load 1579953-1.html
 pref(layout.css.column-span.enabled,true) load 1580576.html
+load empty-mask.html

new file mode 100644
--- /dev/null
+++ b/layout/base/crashtests/empty-mask.html
@@ -0,0 +1,14 @@
+<style>
+* {
+  -webkit-transform: scaleY(96);
+  float: left;
+  border-top: 4em solid
+}
+#a {
+  clip-path: polygon(0px 0px, 1px 0px, 48px 1px);
+}
+</style>
+<time>
+<ul>
+<li id="a">
+A