From 87e044db18dd9171a1e16e6e8debc0d062176c3a Mon Sep 17 00:00:00 2001
From: ldm0 <ldm2993593805@163.com>
Date: Mon, 19 Oct 2026 02:27:12 +0800
Subject: [PATCH] fix(layout): preserve intrinsic width keywords across inline
 formatting roles

Subtract horizontal margins for explicit inline-block fit-content widths and carry float min/max-content constraints across the IFC boundary. Cover six font-backed role/keyword combinations, including an inline break that exercises the float path.

Validation: cargo fmt --all; cargo clippy --workspace --all-targets --all-features -- -D warnings; cargo nextest run --no-fail-fast (20284 passed, 18 skipped). The combined working tree passed these checks before this logical split. Frozen Release and focused browser/WPT validation also passed; final full WPT is running.

Original-commit: 00cfb54b45af1087f880c59856c9eba3c4255019
---
 moli-layout/src/intrinsic.rs               |  2 +-
 moli-layout/src/taffy_tree.rs              | 12 ++++++++-
 moli/tests/fetch_cli/layout_regressions.rs | 30 ++++++++++++++++++++++
 3 files changed, 42 insertions(+), 2 deletions(-)

diff --git a/moli-layout/src/intrinsic.rs b/moli-layout/src/intrinsic.rs
index 6c4d3e1f95..83aa88c0c9 100644
--- a/moli-layout/src/intrinsic.rs
+++ b/moli-layout/src/intrinsic.rs
@@ -81,7 +81,7 @@ where
         let preferred_width = layout_box.style.taffy.size.width;
         let is_replaced = layout_box.is_replaced();
         let uses_fit_content = !layout_box.is_replaced()
-            && layout_box.style.taffy.size.width.is_auto()
+            && (preferred_width.is_auto() || preferred_width.is_fit_content())
             && matches!(
                 layout_box.style.display(),
                 LayoutDisplay::InlineBlock
diff --git a/moli-layout/src/taffy_tree.rs b/moli-layout/src/taffy_tree.rs
index 498c5baa9a..ac673a63ed 100644
--- a/moli-layout/src/taffy_tree.rs
+++ b/moli-layout/src/taffy_tree.rs
@@ -2915,10 +2915,20 @@ where
                     // All floats receive the space remaining after horizontal
                     // margins, matching Taffy's block-float parent. Replaced
                     // measurement carries this ownership explicitly.
+                    let available_width = if style.size.width.is_min_content() {
+                        AvailableSpace::MinContent
+                    } else if style.size.width.is_max_content() {
+                        AvailableSpace::MaxContent
+                    } else {
+                        child_inputs
+                            .available_space
+                            .width
+                            .maybe_sub(margin.left + margin.right)
+                    };
                     let layout_inputs = LayoutInput {
                         available_space: child_inputs
                             .available_space
-                            .map_width(|width| width.maybe_sub(margin.left + margin.right)),
+                            .map_width(|_| available_width),
                         ..child_inputs
                     };
                     let output = self.compute_child_layout(child.to_taffy(), layout_inputs);
diff --git a/moli/tests/fetch_cli/layout_regressions.rs b/moli/tests/fetch_cli/layout_regressions.rs
index de167f9607..f6934b287c 100644
--- a/moli/tests/fetch_cli/layout_regressions.rs
+++ b/moli/tests/fetch_cli/layout_regressions.rs
@@ -184,3 +184,33 @@ fn flex_percentage_padding_keeps_the_text_content_width_before_line_breaking() -
     }
     Ok(())
 }
+
+#[test]
+fn intrinsic_width_keywords_keep_margin_space_for_float_and_inline_roles() -> Result<()> {
+    let mut body = String::new();
+    for role in ["float", "inline"] {
+        for (keyword, _) in [
+            ("min-content", 46.0),
+            ("fit-content", 70.0),
+            ("max-content", 94.0),
+        ] {
+            let display = if role == "float" {
+                "float:left"
+            } else {
+                "display:inline-block"
+            };
+            body.push_str(&format!("<section style='width:80px;height:100px'><div id='{role}-{keyword}' style='{display};width:{keyword};margin:5px;padding:2px;border:3px solid'>aaa bbb</div><br></section>"));
+        }
+    }
+    let value = run_layout(&probe_font_document(&body), GEOMETRY, true)?;
+    for role in ["float", "inline"] {
+        for (keyword, width) in [
+            ("min-content", 46.0),
+            ("fit-content", 70.0),
+            ("max-content", 94.0),
+        ] {
+            assert_dimension(&value, &format!("{role}-{keyword}"), "width", width);
+        }
+    }
+    Ok(())
+}