diff --git a/layout/generic/StickyScrollContainer.cpp b/layout/generic/StickyScrollContainer.cpp
index 5616ad3fbe4b..9d49b56cc445 100644
--- a/layout/generic/StickyScrollContainer.cpp
+++ b/layout/generic/StickyScrollContainer.cpp
@@ -345,7 +345,16 @@ void StickyScrollContainer::GetScrollRanges(nsIFrame* aFrame,
void StickyScrollContainer::PositionContinuations(nsIFrame* aFrame) {
NS_ASSERTION(nsLayoutUtils::IsFirstContinuationOrIBSplitSibling(aFrame),
"Should be starting from the first continuation");
- nsPoint translation = ComputePosition(aFrame) - aFrame->GetNormalPosition();
+ bool hadProperty;
+ nsPoint translation =
+ ComputePosition(aFrame) - aFrame->GetNormalPosition(&hadProperty);
+ if (NS_WARN_IF(!hadProperty)) {
+ // If the frame was never relatively positioned, don't move its position
+ // dynamically. There are a variety of frames for which `position` doesn't
+ // really apply like frames inside svg which would get here and be sticky
+ // only in one direction.
+ return;
+ }
// Move all continuation frames by the same amount.
for (nsIFrame* cont = aFrame; cont;
diff --git a/layout/tables/nsTableWrapperFrame.cpp b/layout/tables/nsTableWrapperFrame.cpp
index c2e3c290e93e..25ed8230848b 100644
--- a/layout/tables/nsTableWrapperFrame.cpp
+++ b/layout/tables/nsTableWrapperFrame.cpp
@@ -1010,7 +1010,7 @@ void nsTableWrapperFrame::Reflow(nsPresContext* aPresContext,
captionMargin, captionOrigin, wm);
FinishReflowChild(mCaptionFrames.FirstChild(), aPresContext, *captionMet,
captionRI.ptr(), wm, captionOrigin, containerSize,
- ReflowChildFlags::Default);
+ ReflowChildFlags::ApplyRelativePositioning);
captionRI.reset();
}
// XXX If the bsize is constrained then we need to check whether
@@ -1019,6 +1019,7 @@ void nsTableWrapperFrame::Reflow(nsPresContext* aPresContext,
LogicalPoint innerOrigin(wm);
GetInnerOrigin(captionSide, containSize, captionSize, captionMargin,
innerSize, innerOrigin, wm);
+ // NOTE: Relative positioning on the table applies to the whole table wrapper.
FinishReflowChild(InnerTableFrame(), aPresContext, innerMet, innerRI.ptr(),
wm, innerOrigin, containerSize, ReflowChildFlags::Default);
innerRI.reset();
diff --git a/testing/web-platform/tests/css/css-position/position-relative-table-caption.html b/testing/web-platform/tests/css/css-position/position-relative-table-caption.html
new file mode 100644
index 000000000000..20ff62888008
--- /dev/null
+++ b/testing/web-platform/tests/css/css-position/position-relative-table-caption.html
@@ -0,0 +1,43 @@
+
+position:relative should work on table captions
+
+
+
+
+
+
+
+
+
+
+
+
+
You should see a green box above. No red should be visible.