diff --git a/layout/generic/TextOverflow.cpp b/layout/generic/TextOverflow.cpp
index 0b07131d6ff7..e8b0d8902c78 100644
--- a/layout/generic/TextOverflow.cpp
+++ b/layout/generic/TextOverflow.cpp
@@ -4719,9 +4719,8 @@ f
 f
 -
 >
-HasAnyStateBits
+HasLineClampEllipsis
 (
-NS_BLOCK_HAS_LINE_CLAMP_ELLIPSIS
 )
 ;
 }
@@ -4754,9 +4753,8 @@ return
 aBlockFrame
 -
 >
-HasAnyStateBits
+HasLineClampEllipsis
 (
-NS_BLOCK_HAS_LINE_CLAMP_ELLIPSIS
 )
 ;
 }
diff --git a/layout/generic/nsBlockFrame.cpp b/layout/generic/nsBlockFrame.cpp
index e3e3a852acc7..6ec16e3781cf 100644
--- a/layout/generic/nsBlockFrame.cpp
+++ b/layout/generic/nsBlockFrame.cpp
@@ -6454,8 +6454,6 @@ nsIFrame
 aFrame
 )
 {
-if
-(
 const
 nsBlockFrame
 *
@@ -6465,29 +6463,51 @@ do_QueryFrame
 (
 aFrame
 )
+;
+if
+(
+!
+block
 )
 {
+return
+nullptr
+;
+}
 if
 (
-!
 block
 -
 >
-HasAnyStateBits
+HasAllStateBits
 (
-NS_BLOCK_BFC
+NS_FRAME_OUT_OF_FLOW
 )
 )
 {
 return
-block
+nullptr
 ;
 }
-}
+if
+(
+block
+-
+>
+HasAllStateBits
+(
+NS_BLOCK_BFC
+)
+)
+{
 return
 nullptr
 ;
 }
+return
+block
+;
+}
 static
 nsBlockFrame
 *
@@ -7239,104 +7259,129 @@ aFrame
 {
 if
 (
-!
 aFrame
 -
 >
-HasAnyStateBits
+HasLineClampEllipsis
 (
-NS_BLOCK_HAS_LINE_CLAMP_ELLIPSIS
 )
 )
 {
+MOZ_ASSERT
+(
+!
+aFrame
+-
+>
+HasLineClampEllipsisDescendant
+(
+)
+)
+;
 for
 (
-nsIFrame
-*
-f
+auto
+&
+line
 :
 aFrame
 -
 >
-PrincipalChildList
+Lines
 (
 )
 )
 {
 if
 (
-nsBlockFrame
-*
-child
-=
-GetAsLineClampDescendant
+line
+.
+HasLineClampEllipsis
 (
-f
 )
 )
 {
-if
-(
-ClearLineClampEllipsis
+line
+.
+ClearHasLineClampEllipsis
 (
-child
 )
+;
+aFrame
+-
+>
+SetHasLineClampEllipsis
+(
+false
 )
-{
+;
 return
 true
 ;
 }
 }
 }
-return
-false
-;
-}
+if
+(
 aFrame
 -
 >
-RemoveStateBits
+HasLineClampEllipsisDescendant
 (
-NS_BLOCK_HAS_LINE_CLAMP_ELLIPSIS
+)
+)
+{
+aFrame
+-
+>
+SetHasLineClampEllipsisDescendant
+(
+false
 )
 ;
 for
 (
-auto
-&
-line
+nsIFrame
+*
+f
 :
 aFrame
 -
 >
-Lines
+PrincipalChildList
 (
 )
 )
 {
 if
 (
-line
-.
-HasLineClampEllipsis
+nsBlockFrame
+*
+child
+=
+GetAsLineClampDescendant
 (
+f
 )
 )
 {
-line
-.
-ClearHasLineClampEllipsis
+if
+(
+ClearLineClampEllipsis
 (
+child
 )
-;
+)
+{
 return
 true
 ;
 }
 }
+}
+}
 return
-true
+false
 ;
 }
 void
@@ -10203,21 +10248,10 @@ PhysicalSize
 ;
 }
 }
-if
-(
-aReflowInput
-.
-mStyleDisplay
--
->
-mWebkitLineClamp
-)
-{
 ClearLineClampEllipsis
 (
 )
 ;
-}
 CheckFloats
 (
 state
@@ -10354,9 +10388,8 @@ MOZ_ASSERT
 aFrame
 -
 >
-HasAnyStateBits
+HasLineClampEllipsis
 (
-NS_BLOCK_HAS_LINE_CLAMP_ELLIPSIS
 )
 "
 Should
@@ -10583,9 +10616,9 @@ SetHasLineClampEllipsis
 target
 -
 >
-AddStateBits
+SetHasLineClampEllipsis
 (
-NS_BLOCK_HAS_LINE_CLAMP_ELLIPSIS
+true
 )
 ;
 nscoord
@@ -10618,6 +10651,45 @@ GetParent
 )
 )
 {
+MOZ_ASSERT
+(
+f
+-
+>
+IsBlockFrameOrSubclass
+(
+)
+"
+GetAsLineClampDescendant
+guarantees
+this
+"
+)
+;
+if
+(
+f
+!
+=
+target
+)
+{
+static_cast
+<
+nsBlockFrame
+*
+>
+(
+f
+)
+-
+>
+SetHasLineClampEllipsisDescendant
+(
+true
+)
+;
+}
 if
 (
 f
@@ -37070,6 +37142,9 @@ aDepth
 int32_t
 &
 aDrawnLines
+bool
+&
+aFoundLineClamp
 )
 {
 #
@@ -37225,6 +37300,60 @@ GetNextSibling
 }
 if
 (
+aFrame
+-
+>
+HasLineClampEllipsisDescendant
+(
+)
+&
+&
+!
+aLineInLine
+)
+{
+if
+(
+nsBlockFrame
+*
+f
+=
+GetAsLineClampDescendant
+(
+aLine
+-
+>
+mFirstChild
+)
+)
+{
+if
+(
+f
+-
+>
+HasLineClampEllipsis
+(
+)
+|
+|
+f
+-
+>
+HasLineClampEllipsisDescendant
+(
+)
+)
+{
+aFoundLineClamp
+=
+true
+;
+}
+}
+}
+if
+(
 aTextOverflow
 &
 &
@@ -37697,6 +37826,16 @@ isSome
 |
 |
 backplateColor
+|
+|
+HasLineClampEllipsis
+(
+)
+|
+|
+HasLineClampEllipsisDescendant
+(
+)
 )
 ?
 nullptr
@@ -37731,6 +37870,11 @@ ptrOr
 nullptr
 )
 ;
+bool
+foundClamp
+=
+false
+;
 if
 (
 cursor
@@ -37834,6 +37978,13 @@ nullptr
 0
 depth
 drawnLines
+foundClamp
+)
+;
+MOZ_ASSERT
+(
+!
+foundClamp
 )
 ;
 }
@@ -37972,6 +38123,7 @@ textOverflowPtr
 lineCount
 depth
 drawnLines
+foundClamp
 )
 ;
 }
@@ -38134,6 +38286,26 @@ lineBackplate
 }
 }
 }
+foundClamp
+=
+foundClamp
+|
+|
+line
+-
+>
+HasLineClampEllipsis
+(
+)
+;
+if
+(
+foundClamp
+)
+{
+break
+;
+}
 lineCount
 +
 +
diff --git a/layout/generic/nsBlockFrame.h b/layout/generic/nsBlockFrame.h
index e6b1477d3a3e..61bca0eebb60 100644
--- a/layout/generic/nsBlockFrame.h
+++ b/layout/generic/nsBlockFrame.h
@@ -1906,6 +1906,60 @@ MaybeHasFloats
 )
 const
 ;
+bool
+HasLineClampEllipsis
+(
+)
+const
+{
+return
+HasAnyStateBits
+(
+NS_BLOCK_HAS_LINE_CLAMP_ELLIPSIS
+)
+;
+}
+bool
+HasLineClampEllipsisDescendant
+(
+)
+const
+{
+return
+HasAnyStateBits
+(
+NS_BLOCK_HAS_LINE_CLAMP_ELLIPSIS_DESCENDANT
+)
+;
+}
+void
+SetHasLineClampEllipsis
+(
+bool
+aValue
+)
+{
+AddOrRemoveStateBits
+(
+NS_BLOCK_HAS_LINE_CLAMP_ELLIPSIS
+aValue
+)
+;
+}
+void
+SetHasLineClampEllipsisDescendant
+(
+bool
+aValue
+)
+{
+AddOrRemoveStateBits
+(
+NS_BLOCK_HAS_LINE_CLAMP_ELLIPSIS_DESCENDANT
+aValue
+)
+;
+}
 protected
 :
 nsBlockFrame
diff --git a/layout/generic/nsFrameStateBits.h b/layout/generic/nsFrameStateBits.h
index bdfd0c242410..f9265a6ee77a 100644
--- a/layout/generic/nsFrameStateBits.h
+++ b/layout/generic/nsFrameStateBits.h
@@ -679,25 +679,31 @@ NS_BLOCK_NEEDS_BIDI_RESOLUTION
 FRAME_STATE_BIT
 (
 Block
-60
+30
 NS_BLOCK_HAS_LINE_CLAMP_ELLIPSIS
 )
 FRAME_STATE_BIT
 (
 Block
-61
+31
+NS_BLOCK_HAS_LINE_CLAMP_ELLIPSIS_DESCENDANT
+)
+FRAME_STATE_BIT
+(
+Block
+60
 NS_BLOCK_LOOK_FOR_DIRTY_FRAMES
 )
 FRAME_STATE_BIT
 (
 Block
-62
+61
 NS_BLOCK_INTRINSICS_INFLATED
 )
 FRAME_STATE_BIT
 (
 Block
-63
+62
 NS_BLOCK_HAS_FIRST_LETTER_CHILD
 )
 FRAME_STATE_GROUP
diff --git a/testing/web-platform/tests/css/css-overflow/line-clamp/reference/webkit-line-clamp-040-ref.html b/testing/web-platform/tests/css/css-overflow/line-clamp/reference/webkit-line-clamp-040-ref.html
index 211bece6d8d7..595c27d2c8be 100644
--- a/testing/web-platform/tests/css/css-overflow/line-clamp/reference/webkit-line-clamp-040-ref.html
+++ b/testing/web-platform/tests/css/css-overflow/line-clamp/reference/webkit-line-clamp-040-ref.html
@@ -69,12 +69,6 @@
 1
 Line
 2
-Line
-3
-Line
-4
-Line
-5
 <
 /
 div
diff --git a/testing/web-platform/tests/css/css-overflow/line-clamp/webkit-line-clamp-050.html b/testing/web-platform/tests/css/css-overflow/line-clamp/webkit-line-clamp-050.html
index 4dd01285adfd..414e7b1a1889 100644
--- a/testing/web-platform/tests/css/css-overflow/line-clamp/webkit-line-clamp-050.html
+++ b/testing/web-platform/tests/css/css-overflow/line-clamp/webkit-line-clamp-050.html
@@ -158,28 +158,6 @@
 15px
 ;
 }
-span
-{
-/
-*
-TODO
-:
-Remove
-once
-we
-don
-'
-t
-paint
-clamped
-lines
-*
-/
-color
-:
-transparent
-;
-}
 <
 /
 style
@@ -200,27 +178,13 @@
 <
 br
 >
-<
-span
->
 Line3
 <
 /
-span
->
-<
-/
 div
 >
-<
-span
->
 Line4
 <
-/
-span
->
-<
 div
 >
 Line5