From 3e6d8f686b796ac1dd2e046e58892ab0042abf15 Mon Sep 17 00:00:00 2001
From: "Dylan M. Taylor" <dylan@dylanmtaylor.com>
Date: Wed, 11 Nov 2026 09:59:01 +0000
Subject: [PATCH] Pass the runs' ordered flag with them to stay under the
 argument limit

---
 crates/text/src/layout.rs | 40 +++++++++++++++++++--------------------
 1 file changed, 19 insertions(+), 21 deletions(-)

diff --git a/crates/text/src/layout.rs b/crates/text/src/layout.rs
index 6ab393cd9..408efa437 100644
--- a/crates/text/src/layout.rs
+++ b/crates/text/src/layout.rs
@@ -634,6 +634,13 @@ fn runs_ordered(runs: &[(Range<usize>, TextStyle)]) -> bool {
     runs.windows(2).all(|w| w[0].0.end <= w[1].0.start)
 }
 
+/// Style runs with whether they are [`runs_ordered`].
+#[derive(Clone, Copy)]
+struct Runs<'a> {
+    list: &'a [(Range<usize>, TextStyle)],
+    ordered: bool,
+}
+
 /// The style run index covering global byte `b` (the run before it at a boundary, for empty
 /// paragraphs at the end). `ordered` is [`runs_ordered`] of `runs`.
 fn run_at(runs: &[(Range<usize>, TextStyle)], ordered: bool, b: usize) -> usize {
@@ -721,8 +728,7 @@ impl<'a> Para<'a> {
     fn new(
         text: &'a str,
         base: usize,
-        runs: &'a [(Range<usize>, TextStyle)],
-        ordered: bool,
+        runs: Runs<'a>,
         primaries: &'a [Resolved],
         variation_ids: &'a [u32],
         para: &'a ParagraphStyle,
@@ -731,8 +737,8 @@ impl<'a> Para<'a> {
         let default_level = para.rtl.map(|r| if r { Level::rtl() } else { Level::ltr() });
         let bidi = BidiInfo::new(text, default_level);
         let base_rtl = bidi.paragraphs[0].level.is_rtl();
-        let chars = char_forms(text, base, runs, ordered, primaries, &bidi);
-        let items = build_items(text, &chars, runs);
+        let chars = char_forms(text, base, runs, primaries, &bidi);
+        let items = build_items(text, &chars, runs.list);
         // Prefix widths and the preceding non-whitespace boundary make candidate line widths O(1).
         // Every-line composition evaluates O(n²) candidate breaks; summing each candidate's bytes
         // or rescanning its trailing whitespace would otherwise add another factor of text length.
@@ -755,7 +761,7 @@ impl<'a> Para<'a> {
             }
             previous_non_ws[b + c.len_utf8()] = non_ws_end;
         }
-        Para { text, base, runs, primaries, variation_ids, para, width, bidi, base_rtl, chars, items, char_adv, prefix_adv, previous_non_ws }
+        Para { text, base, runs: runs.list, primaries, variation_ids, para, width, bidi, base_rtl, chars, items, char_adv, prefix_adv, previous_non_ws }
     }
 
     fn range_w(&self, r: Range<usize>) -> f32 {
@@ -1037,11 +1043,11 @@ impl<'a> Para<'a> {
 }
 
 /// Each char with its shaped form, face, direction and run.
-fn char_forms(text: &str, base: usize, runs: &[(Range<usize>, TextStyle)], ordered: bool, primaries: &[Resolved], bidi: &BidiInfo) -> Vec<CharInfo> {
+fn char_forms(text: &str, base: usize, runs: Runs, primaries: &[Resolved], bidi: &BidiInfo) -> Vec<CharInfo> {
     text.char_indices()
         .map(|(b, c)| {
-            let si = run_at(runs, ordered, base + b);
-            let style = &runs[si].1;
+            let si = run_at(runs.list, runs.ordered, base + b);
+            let style = &runs.list[si].1;
             let primary = primaries[si].face;
             let face_of = |ch: char| if ch.is_whitespace() { primary } else { fonts::fallback_for(ch, primary) };
             let all_small = style.opentype.all_small_caps && style.caps != Caps::All;
@@ -1095,18 +1101,9 @@ fn build_items(text: &str, chars: &[CharInfo], runs: &[(Range<usize>, TextStyle)
     items
 }
 
-fn paragraph(
-    text: &str,
-    base: usize,
-    runs: &[(Range<usize>, TextStyle)],
-    ordered: bool,
-    primaries: &[Resolved],
-    variation_ids: &[u32],
-    para: &ParagraphStyle,
-    width: Option<f32>,
-) -> Vec<ParaLine> {
+fn paragraph(text: &str, base: usize, runs: Runs, primaries: &[Resolved], variation_ids: &[u32], para: &ParagraphStyle, width: Option<f32>) -> Vec<ParaLine> {
     if text.is_empty() {
-        let si = run_at(runs, ordered, base);
+        let (runs, si) = (runs.list, run_at(runs.list, runs.ordered, base));
         let pm = style_metrics(primaries, runs, si);
         // No text to resolve a direction from: the explicit one.
         let rtl = para.rtl == Some(true);
@@ -1127,7 +1124,7 @@ fn paragraph(
             underline: None,
         }];
     }
-    let p = Para::new(text, base, runs, ordered, primaries, variation_ids, para, width);
+    let p = Para::new(text, base, runs, primaries, variation_ids, para, width);
     let ranges = p.break_ranges();
     let nlines = ranges.len();
     ranges.into_iter().enumerate().map(|(li, r)| p.place_line(li, r, li + 1 == nlines)).collect()
@@ -1189,7 +1186,8 @@ pub fn layout_rich_uncached(text: &str, runs: &[(Range<usize>, TextStyle)], para
     let mut plines: Vec<(usize, ParaLine)> = Vec::new();
     for (pi, span) in paragraph_ranges(text).enumerate() {
         let p = text.get(span.bytes.clone()).unwrap_or_default();
-        plines.extend(paragraph(p, span.bytes.start, runs, ordered, &primaries, &variation_ids, para_at(pi), width).into_iter().map(|l| (pi, l)));
+        plines
+            .extend(paragraph(p, span.bytes.start, Runs { list: runs, ordered }, &primaries, &variation_ids, para_at(pi), width).into_iter().map(|l| (pi, l)));
     }
     let mut baseline = 0.0f32;
     for (i, (pi, pl)) in plines.into_iter().enumerate() {