diff --git a/layout/generic/nsGridContainerFrame.cpp b/layout/generic/nsGridContainerFrame.cpp
index c3cc092aaf82..2f2ae0717e89 100644
--- a/layout/generic/nsGridContainerFrame.cpp
+++ b/layout/generic/nsGridContainerFrame.cpp
@@ -5988,7 +5988,7 @@ nsGridContainerFrame::Reflow(nsPresContext* aPresContext,
const nscoord computedBSize = aReflowInput.ComputedBSize();
const nscoord computedISize = aReflowInput.ComputedISize();
const WritingMode& wm = gridReflowInput.mWM;
- LogicalSize computedSize(wm, computedISize, computedBSize);
+ const LogicalSize computedSize(wm, computedISize, computedBSize);
nscoord consumedBSize = 0;
nscoord bSize = 0;
@@ -5999,18 +5999,28 @@ nsGridContainerFrame::Reflow(nsPresContext* aPresContext,
gridReflowInput.CalculateTrackSizes(grid, computedSize,
SizingConstraint::eNoConstraint);
- // Note: we can't use GridLineEdge here since we haven't calculated
- // the rows' mPosition yet (happens in AlignJustifyContent below).
- for (const auto& sz : gridReflowInput.mRows.mSizes) {
- bSize += sz.mBase;
+ // XXX Technically incorrect: We're ignoring our row sizes, when really
+ // we should use them but *they* should be computed as if we had no
+ // children. To be fixed in bug 1488878.
+ if (!aReflowInput.mStyleDisplay->IsContainSize()) {
+ // Note: we can't use GridLineEdge here since we haven't calculated
+ // the rows' mPosition yet (happens in AlignJustifyContent below).
+ for (const auto& sz : gridReflowInput.mRows.mSizes) {
+ bSize += sz.mBase;
+ }
+ bSize += gridReflowInput.mRows.SumOfGridGaps();
}
- bSize += gridReflowInput.mRows.SumOfGridGaps();
} else {
consumedBSize = ConsumedBSize(wm);
gridReflowInput.InitializeForContinuation(this, consumedBSize);
- const uint32_t numRows = gridReflowInput.mRows.mSizes.Length();
- bSize = gridReflowInput.mRows.GridLineEdge(numRows,
- GridLineSide::eAfterGridGap);
+ // XXX Technically incorrect: We're ignoring our row sizes, when really
+ // we should use them but *they* should be computed as if we had no
+ // children. To be fixed in bug 1488878.
+ if (!aReflowInput.mStyleDisplay->IsContainSize()) {
+ const uint32_t numRows = gridReflowInput.mRows.mSizes.Length();
+ bSize = gridReflowInput.mRows.GridLineEdge(numRows,
+ GridLineSide::eAfterGridGap);
+ }
}
if (computedBSize == NS_AUTOHEIGHT) {
bSize = NS_CSS_MINMAX(bSize,
@@ -6476,7 +6486,9 @@ nsGridContainerFrame::GetMinISize(gfxContext* aRC)
{
DISPLAY_MIN_WIDTH(this, mCachedMinISize);
if (mCachedMinISize == NS_INTRINSIC_WIDTH_UNKNOWN) {
- mCachedMinISize = IntrinsicISize(aRC, nsLayoutUtils::MIN_ISIZE);
+ mCachedMinISize = StyleDisplay()->IsContainSize()
+ ? 0
+ : IntrinsicISize(aRC, nsLayoutUtils::MIN_ISIZE);
}
return mCachedMinISize;
}
@@ -6486,7 +6498,9 @@ nsGridContainerFrame::GetPrefISize(gfxContext* aRC)
{
DISPLAY_PREF_WIDTH(this, mCachedPrefISize);
if (mCachedPrefISize == NS_INTRINSIC_WIDTH_UNKNOWN) {
- mCachedPrefISize = IntrinsicISize(aRC, nsLayoutUtils::PREF_ISIZE);
+ mCachedPrefISize = StyleDisplay()->IsContainSize()
+ ? 0
+ : IntrinsicISize(aRC, nsLayoutUtils::PREF_ISIZE);
}
return mCachedPrefISize;
}
diff --git a/layout/reftests/w3c-css/submitted/contain/contain-size-grid-001-ref.html b/layout/reftests/w3c-css/submitted/contain/contain-size-grid-001-ref.html
new file mode 100644
index 000000000000..b2fdf4b88769
--- /dev/null
+++ b/layout/reftests/w3c-css/submitted/contain/contain-size-grid-001-ref.html
@@ -0,0 +1,49 @@
+
+
+
+
+ CSS Reftest Reference
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
diff --git a/layout/reftests/w3c-css/submitted/contain/contain-size-grid-001.html b/layout/reftests/w3c-css/submitted/contain/contain-size-grid-001.html
new file mode 100644
index 000000000000..a85b0a3138de
--- /dev/null
+++ b/layout/reftests/w3c-css/submitted/contain/contain-size-grid-001.html
@@ -0,0 +1,72 @@
+
+
+
+
+ CSS Test: 'contain: size' on grid elements should cause them to be sized and baseline-aligned as if they had no contents.
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
diff --git a/layout/reftests/w3c-css/submitted/contain/reftest.list b/layout/reftests/w3c-css/submitted/contain/reftest.list
index d2d4685348e9..c3836767cdab 100644
--- a/layout/reftests/w3c-css/submitted/contain/reftest.list
+++ b/layout/reftests/w3c-css/submitted/contain/reftest.list
@@ -22,6 +22,7 @@ pref(layout.css.overflow-clip-box.enabled,true) == contain-paint-clip-006.html c
== contain-size-inline-block-001.html contain-size-inline-block-001-ref.html
== contain-size-flex-001.html contain-size-flex-001-ref.html
fuzzy-if(webrender&&winWidget,0-3,0-2) == contain-size-inline-flex-001.html contain-size-inline-flex-001-ref.html # bug 1474093
+== contain-size-grid-001.html contain-size-grid-001-ref.html
== contain-size-multicol-001.html contain-size-multicol-001-ref.html
== contain-size-fieldset-001.html contain-size-fieldset-001-ref.html
== contain-size-fieldset-002.html contain-size-fieldset-002-ref.html