diff --git a/components/layout/block.rs b/components/layout/block.rs
index 1f4eb92ea51..80c0fae2243 100644
--- a/components/layout/block.rs
+++ b/components/layout/block.rs
@@ -1682,6 +1682,13 @@ impl BlockFlow {
/// Determines the type of formatting context this is. See the definition of
/// `FormattingContextType`.
pub fn formatting_context_type(&self) -> FormattingContextType {
+ if self
+ .base
+ .flags
+ .contains(FlowFlags::IS_ABSOLUTELY_POSITIONED)
+ {
+ return FormattingContextType::Other;
+ }
if self.is_inline_flex_item() || self.is_block_flex_item() {
return FormattingContextType::Other;
}
diff --git a/tests/wpt/mozilla/meta/MANIFEST.json b/tests/wpt/mozilla/meta/MANIFEST.json
index e5fcf55da15..a7a9a02bf42 100644
--- a/tests/wpt/mozilla/meta/MANIFEST.json
+++ b/tests/wpt/mozilla/meta/MANIFEST.json
@@ -43,6 +43,18 @@
{}
]
],
+ "css/absolute_block_format_ctx.html": [
+ [
+ "css/absolute_block_format_ctx.html",
+ [
+ [
+ "/_mozilla/css/absolute_block_format_ctx_ref.html",
+ "=="
+ ]
+ ],
+ {}
+ ]
+ ],
"css/absolute_clipping_of_own_contents.html": [
[
"css/absolute_clipping_of_own_contents.html",
@@ -7692,6 +7704,9 @@
"css/abs_rel_explicit_height_ref.html": [
[]
],
+ "css/absolute_block_format_ctx_ref.html": [
+ []
+ ],
"css/absolute_clipping_of_own_contents_ref.html": [
[]
],
@@ -13461,6 +13476,14 @@
"4e9833c29529e58690f5f26e546e0d66a22ca369",
"support"
],
+ "css/absolute_block_format_ctx.html": [
+ "e7540c1cfe8eaab06e9c3b87214263d2c3abec34",
+ "reftest"
+ ],
+ "css/absolute_block_format_ctx_ref.html": [
+ "42420061724718702f611abd2ff4c61774fc4b86",
+ "support"
+ ],
"css/absolute_clipping_of_own_contents.html": [
"19919ff89c72d3425d188c49c27916a9eb885359",
"reftest"
diff --git a/tests/wpt/mozilla/tests/css/absolute_block_format_ctx.html b/tests/wpt/mozilla/tests/css/absolute_block_format_ctx.html
new file mode 100644
index 00000000000..e7540c1cfe8
--- /dev/null
+++ b/tests/wpt/mozilla/tests/css/absolute_block_format_ctx.html
@@ -0,0 +1,25 @@
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
diff --git a/tests/wpt/mozilla/tests/css/absolute_block_format_ctx_ref.html b/tests/wpt/mozilla/tests/css/absolute_block_format_ctx_ref.html
new file mode 100644
index 00000000000..42420061724
--- /dev/null
+++ b/tests/wpt/mozilla/tests/css/absolute_block_format_ctx_ref.html
@@ -0,0 +1,16 @@
+
+
+
+
+
+
+
+
+
+