From 0d4b5979832129794da4a6402fbf4a2ad32d2c83 Mon Sep 17 00:00:00 2001
From: "Ayberk A." <105879357+AyberkA0@users.noreply.github.com>
Date: Sat, 17 Oct 2026 00:04:01 +0300
Subject: [PATCH] AI import: a gradient stop naming a process colour leaves its
 swatch process (#1771)

A colour named by a gradient stop (`Bs`) was collected with the colours the
colour operators define, in file order, and the first definition of a name
made its swatch. A stop can't say whether its colour is an ink, so it reads
as a spot colour; and since the file defines its gradients before the art,
a global process colour set with `Xk` that a gradient also names came in as
a spot swatch, which PDF export then writes as a Separation. The stops'
named colours are now kept apart and make swatches only after the colour
operators' colours, so `Xk`'s definition wins and a name only a stop uses
still gets its swatch. The stop's values were already read right since the
lexer reads a `%_BS` line's own operands.
---
 crates/eps/src/import/ai/read.rs  | 12 ++++++++++--
 crates/eps/src/import/ai/tests.rs | 23 +++++++++++++++++++++++
 2 files changed, 33 insertions(+), 2 deletions(-)

diff --git a/crates/eps/src/import/ai/read.rs b/crates/eps/src/import/ai/read.rs
index d12a569e3..deb91345f 100644
--- a/crates/eps/src/import/ai/read.rs
+++ b/crates/eps/src/import/ai/read.rs
@@ -461,7 +461,11 @@ struct Reader<'a> {
     instance: Option<Instance>,
     pending_fill: Option<Paint>,
     pending_stroke: Option<Paint>,
+    /// The named colours the colour operators define (`x`, `Xx`, `Xk`…).
     spots: Vec<Named>,
+    /// The named colours gradient stops name. A stop doesn't say whether its colour is an ink or
+    /// a global process colour, so these make swatches only for names no colour operator defines.
+    stop_spots: Vec<Named>,
     raster: Option<Raster>,
     /// The placed file being read (`%AI5_BeginPlace` … `~`).
     place: Option<Place>,
@@ -626,6 +630,7 @@ impl<'a> Reader<'a> {
             pending_fill: None,
             pending_stroke: None,
             spots: Vec::new(),
+            stop_spots: Vec::new(),
             raster: None,
             place: None,
             foreign_data: None,
@@ -879,6 +884,7 @@ impl<'a> Reader<'a> {
             self.doc.images.entry(key).or_insert(blob);
         }
         self.spots.extend(sub.spots);
+        self.stop_spots.extend(sub.stop_spots);
         self.cmyk_colors += sub.cmyk_colors;
         self.rgb_colors += sub.rgb_colors;
         for w in &sub.warnings {
@@ -1155,7 +1161,7 @@ impl<'a> Reader<'a> {
         let vals = self.take_head(vals);
         if let Some(d) = self.gradient_def.as_mut() {
             match w {
-                "Bs" => d.stop(&vals, &mut self.spots),
+                "Bs" => d.stop(&vals, &mut self.stop_spots),
                 "BD" => {
                     if let Some((name, g)) = self.gradient_def.take().and_then(GradientDef::finish) {
                         self.gradients.insert(name, g);
@@ -2321,7 +2327,9 @@ impl<'a> Reader<'a> {
         if let Some(u) = self.ruler_units.and_then(ruler_unit) {
             doc.units = u;
         }
-        for n in &self.spots {
+        // The colour operators' definitions first: a gradient, defined before the art, names a
+        // global process colour as a stop and would otherwise make it an ink (#1771).
+        for n in self.spots.iter().chain(&self.stop_spots) {
             if doc.swatch(&n.name).is_none() {
                 doc.swatches.push(Swatch { name: n.name.clone(), paint: Paint::solid(n.color), global: true, spot: n.spot });
             }
diff --git a/crates/eps/src/import/ai/tests.rs b/crates/eps/src/import/ai/tests.rs
index 0ab7b1b67..3bd312297 100644
--- a/crates/eps/src/import/ai/tests.rs
+++ b/crates/eps/src/import/ai/tests.rs
@@ -173,6 +173,29 @@ fn global_process_colours_are_global_swatches_at_their_tint() {
     assert_eq!(doc.swatch("Black global").unwrap().paint.color(), Some(Color::cmyk(0.0, 0.0, 0.0, 1.0)), "the swatch is the full colour");
 }
 
+/// A gradient stop naming a global process colour doesn't make it an ink (#1771): the colour
+/// operator's definition (`Xk`) makes the swatch, though the gradient, defined first, names the
+/// colour first. The lines are the ones posted in #1771, with a neutral name.
+#[test]
+fn a_gradient_stop_naming_a_process_colour_leaves_its_swatch_process() {
+    let defs = "%AI5_BeginGradient: (Brand)\n(Brand) 0 2 Bd\n[\n<00FF>\n0\n\
+                0.930000007152557 0.100000001490116 0 0 1 1 6 50 0 %_BS\n\
+                %_0.930000007152557 0.100000001490116 0 0 (Test Cyan) 0 0 5 1 6 50 0 Bs\n\
+                %_0 0 0 0 1 0 0 2 1 6 50 100 Bs\nBD\n%AI5_EndGradient\n";
+    let art_ = format!("0.930000007152557 0.100000001490116 0 0 (Test Cyan) 0 0 Xk\n{}f\n", rect_path(0.0, 0.0, 10.0, 10.0));
+    let near =
+        |c: Option<Color>| matches!(c, Some(Color::Cmyk { c, m, y, k }) if (c - 0.93).abs() < 1e-3 && (m - 0.1).abs() < 1e-3 && y == 0.0 && k == 0.0);
+    let doc = read_ok(&format!("{defs}{}", layer(&art_))).doc;
+    let sw = doc.swatch("Test Cyan").unwrap();
+    assert!(sw.global && !sw.spot, "a global process colour, not an ink: {sw:?}");
+    assert!(near(sw.paint.color()), "C=93 M=10: {sw:?}");
+    assert!(near(fill(&art(&doc)[0]).color()), "the fill: {:?}", fill(&art(&doc)[0]));
+    // Named only by the stop, the colour is still a swatch of its own, at the stop's values.
+    let doc = read_ok(&format!("{defs}{}", layer(&format!("{}f\n", rect_path(0.0, 0.0, 10.0, 10.0))))).doc;
+    let sw = doc.swatch("Test Cyan").unwrap();
+    assert!(near(sw.paint.color()), "{sw:?}");
+}
+
 /// A pattern's definition (`%AI3_BeginPattern`): its name and tile (8 points square here, y up),
 /// then its art on `%_` lines (a group of the tile's unpainted box and a dot, a round-capped
 /// stroke of no length), `E`.