SVG export: a Japanese face's numbered weight (W0–W9) is its font-weight, W6 600 (#2873)

style_weight reads W0–W9 style names (Hiragino, Morisawa…) as their weight classes before the English words, so SVG and CSS export write font-weight 600 for W6, and nearest-style matching weighs them too.

crates/svg/tests/font_weights.rs

@@ -55,6 +55,13 @@ fn every_style_is_written_with_its_numeric_weight() {
         ("Extrabold", Some("800")),
         ("Black", Some("900")),
         ("Heavy", Some("900")),
+        // Japanese faces' numbered weights (#2873); W4 is the regular weight.
+        ("W0", Some("100")),
+        ("W3", Some("300")),
+        ("W4", None),
+        ("W6", Some("600")),
+        ("W9", Some("900")),
+        ("Wide", None),
     ] {
         let want = want.map(str::to_string);
         assert_eq!(weights(style), (want.clone(), want), "{style}");

crates/text/src/fontdb.rs

@@ -1568,8 +1568,16 @@ fn norm(s: &str) -> String {
     norm_chars(s).collect()
 }
 
-/// Weight implied by a style name (400 = regular).
+/// Weight implied by a style name (400 = regular). Japanese faces number their weights W0–W9
+/// (Hiragino, Morisawa…), W6 weighing 600 as its weight class does (#2873).
 pub fn style_weight(style: &str) -> f32 {
+    let numbered = style.split(|c: char| !c.is_ascii_alphanumeric()).find_map(|part| match part.as_bytes() {
+        [b'W' | b'w', d @ b'0'..=b'9'] => Some(f32::from(d - b'0') * 100.0),
+        _ => None,
+    });
+    if let Some(w) = numbered {
+        return w.max(100.0);
+    }
     let s = norm(style);
     const TABLE: &[(&str, f32)] = &[
         ("extralight", 200.0),

docs/mcp.md

@@ -467,7 +467,7 @@ lists every option with its default. `encoding` is `utf8`, `utf16` (big-endian a
 (presentation attributes only; filters, masks, blend modes and embedded fonts left out, symbols as art, each with
 a warning). `embedFonts: true` embeds the fonts type uses as `@font-face` rules subset to the characters used; a
 font whose licence (OS/2 `fsType`) forbids subsetting is embedded whole, one that forbids embedding is left out
-with a warning. Type names its faces by numeric `font-weight` (600 for Semibold, 300 for Light, `bold` for 700),
+with a warning. Type names its faces by numeric `font-weight` (600 for Semibold and for a Japanese face's W6, 300 for Light, `bold` for 700),
 embedded or not. `svgz` takes the same options and writes the SVG gzipped (`.svgz` files also open,
 place and paste). `run_command document.save {path: "x.svg", svg: {…}}` saves as SVG (or `.svgz`).