From ba24bc7abe9fdb636e36d42ebf2ee3566f416d06 Mon Sep 17 00:00:00 2001
From: ldm0 <ldm2993593805@163.com>
Date: Sat, 29 Aug 2026 02:20:33 +0800
Subject: [PATCH] fix(layout): preserve calc lengths in intrinsic margins

---
 Cargo.lock                                    |  2 +-
 Cargo.toml                                    |  2 +-
 .../tests/intrinsic_percentage_resolution.rs  | 63 +++++++++++++++++++
 .../src/runtime/page_vm/tests/mod.rs          |  1 +
 4 files changed, 66 insertions(+), 2 deletions(-)
 create mode 100644 moli-renderer-v8/src/runtime/page_vm/tests/intrinsic_percentage_resolution.rs

diff --git a/Cargo.lock b/Cargo.lock
index b7967d6474..124ec91978 100644
--- a/Cargo.lock
+++ b/Cargo.lock
@@ -4823,7 +4823,7 @@ dependencies = [
 [[package]]
 name = "taffy"
 version = "0.13.0"
-source = "git+https://github.com/ldm0/taffy?rev=3305c7b51c4c88d698d5d3039cd6c8e828ff2086#3305c7b51c4c88d698d5d3039cd6c8e828ff2086"
+source = "git+https://github.com/ldm0/taffy?rev=b7735b0aba77dd0e98015f3cd1dd26a71f90a415#b7735b0aba77dd0e98015f3cd1dd26a71f90a415"
 dependencies = [
  "arrayvec",
  "serde",
diff --git a/Cargo.toml b/Cargo.toml
index 9158c3c628..6f78bd7fa1 100644
--- a/Cargo.toml
+++ b/Cargo.toml
@@ -98,7 +98,7 @@ stylo_atoms = { git = "https://github.com/ldm0/stylo", rev = "32c3de3f2aab3340c5
 stylo_dom = { git = "https://github.com/ldm0/stylo", rev = "32c3de3f2aab3340c51f03f2a0878d1e4eed7fd6" }
 stylo_static_prefs = { git = "https://github.com/ldm0/stylo", rev = "32c3de3f2aab3340c51f03f2a0878d1e4eed7fd6" }
 stylo_traits = { git = "https://github.com/ldm0/stylo", rev = "32c3de3f2aab3340c51f03f2a0878d1e4eed7fd6" }
-taffy = { git = "https://github.com/ldm0/taffy", rev = "3305c7b51c4c88d698d5d3039cd6c8e828ff2086" }
+taffy = { git = "https://github.com/ldm0/taffy", rev = "b7735b0aba77dd0e98015f3cd1dd26a71f90a415" }
 
 [workspace.lints.clippy]
 disallowed_methods = "deny"
diff --git a/moli-renderer-v8/src/runtime/page_vm/tests/intrinsic_percentage_resolution.rs b/moli-renderer-v8/src/runtime/page_vm/tests/intrinsic_percentage_resolution.rs
new file mode 100644
index 0000000000..04cfd745cb
--- /dev/null
+++ b/moli-renderer-v8/src/runtime/page_vm/tests/intrinsic_percentage_resolution.rs
@@ -0,0 +1,63 @@
+use super::*;
+
+#[tokio::test(flavor = "current_thread")]
+async fn screenshot_keeps_absolute_calc_terms_in_intrinsic_flex_margins() {
+    run_page_vm_async_test(async move {
+        let loader =
+            crate::network::ResourceRequestClient::new(&FetchConfig::default()).expect("loader");
+        let mut page_vm = test_page_vm_with_loader_and_document_url(
+            &loader,
+            Vec::new(),
+            Url::parse("https://example.com/intrinsic-calc-margin.html")?,
+        );
+        page_vm.vm_mut().eval(
+            r#"
+document.head.innerHTML = `<style>
+html,body{margin:0}
+.probe{display:flex;height:20px}
+#mixed,#percentage,#length{width:min-content}
+#mixed>i{margin-left:calc(10% + 100px)}
+#percentage>i{margin-left:10%}
+#length>i{margin-left:100px}
+#definite{width:200px}
+#definite>i{width:1px;height:1px;margin-left:calc(10% + 100px)}
+</style>`;
+document.body.innerHTML = `
+  <div id=mixed class=probe><i></i></div>
+  <div id=percentage class=probe><i></i></div>
+  <div id=length class=probe><i></i></div>
+  <div id=definite class=probe><i id=definite-child></i></div>`;
+'installed'
+"#,
+        )?;
+        page_vm.vm_mut().sync_live_document_style_sources();
+        page_vm
+            .vm_mut()
+            .screenshot_layout_snapshot(moli_layout::PaintViewport::new(400, 100, 1.0))?
+            .expect("intrinsic percentage-resolution screenshot layout");
+
+        let geometry = page_vm.vm_mut().eval(
+            r#"JSON.stringify((()=>{const rect=id=>document.getElementById(id).getBoundingClientRect();const definite=rect('definite'),child=rect('definite-child');return {mixed:rect('mixed').width,percentage:rect('percentage').width,length:rect('length').width,definite:definite.width,definiteChildOffset:child.x-definite.x}})())"#,
+        )?;
+        let geometry: serde_json::Value = serde_json::from_str(&geometry)?;
+        for (name, expected) in [
+            ("mixed", 100.0),
+            ("percentage", 0.0),
+            ("length", 100.0),
+            ("definite", 200.0),
+            ("definiteChildOffset", 120.0),
+        ] {
+            let actual = geometry[name]
+                .as_f64()
+                .unwrap_or_else(|| panic!("missing numeric {name}: {geometry}"))
+                as f32;
+            assert!(
+                (actual - expected).abs() <= 0.05,
+                "{name}: expected {expected}, got {actual}; geometry={geometry}"
+            );
+        }
+        Ok::<_, anyhow::Error>(())
+    })
+    .await
+    .expect("intrinsic calc-margin fixture should run");
+}
diff --git a/moli-renderer-v8/src/runtime/page_vm/tests/mod.rs b/moli-renderer-v8/src/runtime/page_vm/tests/mod.rs
index ef5fe5ef7f..cc3063d4d2 100644
--- a/moli-renderer-v8/src/runtime/page_vm/tests/mod.rs
+++ b/moli-renderer-v8/src/runtime/page_vm/tests/mod.rs
@@ -130,6 +130,7 @@ mod image_root_coordinates;
 mod indexed_db;
 mod inline_svg_paint;
 mod internal_loading_completion;
+mod intrinsic_percentage_resolution;
 mod lifecycle;
 mod main_document_post_parse_completion;
 mod main_document_runtime;