diff --git a/components/layout/table_cell.rs b/components/layout/table_cell.rs
index 58bb96cfbf6..1e36adc65af 100644
--- a/components/layout/table_cell.rs
+++ b/components/layout/table_cell.rs
@@ -80,8 +80,12 @@ impl TableCellFlow {
if !flow::base(self).restyle_damage.contains(REFLOW) {
return;
}
+ // Note to the reader: this code has been tested with negative margins.
+ // We end up with a "end" that's before the "start," but the math still works out.
let first_start = flow::base(self).children.front().map(|kid| {
+ let kid_base = flow::base(kid);
flow::base(kid).position.start.b
+ - kid_base.collapsible_margins.block_start_margin_for_noncollapsible_context()
});
if let Some(mut first_start) = first_start {
let mut last_end = first_start;
diff --git a/tests/wpt/mozilla/meta/MANIFEST.json b/tests/wpt/mozilla/meta/MANIFEST.json
index 32d55768235..e0c9ebfc5af 100644
--- a/tests/wpt/mozilla/meta/MANIFEST.json
+++ b/tests/wpt/mozilla/meta/MANIFEST.json
@@ -4960,6 +4960,18 @@
"url": "/_mozilla/css/table_specified_width_a.html"
}
],
+ "css/table_vertical_align_margin_padding.html": [
+ {
+ "path": "css/table_vertical_align_margin_padding.html",
+ "references": [
+ [
+ "/_mozilla/css/table_vertical_align_margin_padding_ref.html",
+ "=="
+ ]
+ ],
+ "url": "/_mozilla/css/table_vertical_align_margin_padding.html"
+ }
+ ],
"css/table_width_attribute_a.html": [
{
"path": "css/table_width_attribute_a.html",
@@ -12092,6 +12104,18 @@
"url": "/_mozilla/css/table_specified_width_a.html"
}
],
+ "css/table_vertical_align_margin_padding.html": [
+ {
+ "path": "css/table_vertical_align_margin_padding.html",
+ "references": [
+ [
+ "/_mozilla/css/table_vertical_align_margin_padding_ref.html",
+ "=="
+ ]
+ ],
+ "url": "/_mozilla/css/table_vertical_align_margin_padding.html"
+ }
+ ],
"css/table_width_attribute_a.html": [
{
"path": "css/table_width_attribute_a.html",
diff --git a/tests/wpt/mozilla/tests/css/table_vertical_align_margin_padding.html b/tests/wpt/mozilla/tests/css/table_vertical_align_margin_padding.html
new file mode 100644
index 00000000000..3dc9c49c6c3
--- /dev/null
+++ b/tests/wpt/mozilla/tests/css/table_vertical_align_margin_padding.html
@@ -0,0 +1,9 @@
+
+
+Negative margins in a table with middle alignment
+
+
+Test passes if there is a single green box
+
diff --git a/tests/wpt/mozilla/tests/css/table_vertical_align_margin_padding_ref.html b/tests/wpt/mozilla/tests/css/table_vertical_align_margin_padding_ref.html
new file mode 100644
index 00000000000..8ae237dbe2b
--- /dev/null
+++ b/tests/wpt/mozilla/tests/css/table_vertical_align_margin_padding_ref.html
@@ -0,0 +1,9 @@
+
+
+Negative margins in table reference
+
+Test passes if there is a single green box
+
+