diff --git a/layout/reftests/bugs/534808-1-ref.html b/layout/reftests/bugs/534808-1-ref.html
new file mode 100644
index 00000000000..ddb8a855f85
--- /dev/null
+++ b/layout/reftests/bugs/534808-1-ref.html
@@ -0,0 +1,20 @@
+
+
+
+
+
+
+
+
+
+ 
+ |
+
+
+
diff --git a/layout/reftests/bugs/534808-1.html b/layout/reftests/bugs/534808-1.html
new file mode 100644
index 00000000000..c112098dc18
--- /dev/null
+++ b/layout/reftests/bugs/534808-1.html
@@ -0,0 +1,20 @@
+
+
+
+
+
+
+
+
+
+
+ |
+
+
+
diff --git a/layout/reftests/bugs/534808-2-ref.html b/layout/reftests/bugs/534808-2-ref.html
new file mode 100644
index 00000000000..decfe467183
--- /dev/null
+++ b/layout/reftests/bugs/534808-2-ref.html
@@ -0,0 +1,22 @@
+
+
+
+
+
+
+
+
+
+
+
+
+ |
+
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+
diff --git a/layout/reftests/bugs/534808-2.html b/layout/reftests/bugs/534808-2.html
new file mode 100644
index 00000000000..c4a6bd458bd
--- /dev/null
+++ b/layout/reftests/bugs/534808-2.html
@@ -0,0 +1,22 @@
+
+
+
+
+
+
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+
+
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+
+
+ |
+
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diff --git a/layout/reftests/bugs/reftest.list b/layout/reftests/bugs/reftest.list
index 40f1d45cff2..16acbc0f870 100644
--- a/layout/reftests/bugs/reftest.list
+++ b/layout/reftests/bugs/reftest.list
@@ -1359,4 +1359,6 @@ fails HTTP(..) == 518172-2b.html 518172-b-ref.html # bug 518172
== 530686-1.html 530686-1-ref.html
== 531098-1.html 531098-1-ref.html
== 531371-1.html 531371-1-ref.html
+== 534808-1.html 534808-1-ref.html
+== 534808-2.html 534808-2-ref.html
== 534919-1.html 534919-1-ref.html
diff --git a/layout/style/nsStyleStruct.cpp b/layout/style/nsStyleStruct.cpp
index c6ba837a03c..5a82146549f 100644
--- a/layout/style/nsStyleStruct.cpp
+++ b/layout/style/nsStyleStruct.cpp
@@ -1106,14 +1106,13 @@ nsChangeHint nsStylePosition::CalcDifference(const nsStylePosition& aOther) cons
if (mHeight != aOther.mHeight ||
mMinHeight != aOther.mMinHeight ||
mMaxHeight != aOther.mMaxHeight) {
- // Height changes can't affect descendant intrinsic sizes, but due to our
- // not-so-great computation of mVResize in nsHTMLReflowState, do need to
- // force reflow of the whole subtree.
- // XXXbz due to XUL caching heights as well, height changes _do_
- // need to clear ancestor intrinsics!
- return NS_CombineHint(hint,
- NS_SubtractHint(nsChangeHint_ReflowFrame,
- nsChangeHint_ClearDescendantIntrinsics));
+ // Height changes can affect descendant intrinsic sizes due to replaced
+ // elements with percentage heights in descendants which also have
+ // percentage heights. And due to our not-so-great computation of mVResize
+ // in nsHTMLReflowState, they do need to force reflow of the whole subtree.
+ // XXXbz due to XUL caching heights as well, height changes also need to
+ // clear ancestor intrinsics!
+ return NS_CombineHint(hint, nsChangeHint_ReflowFrame);
}
if ((mWidth == aOther.mWidth) &&