Swatch libraries: only a built-in pattern library's own swatches draw its pattern tiles

crates/engine/src/cmd/patternlib.rs

@@ -71,10 +71,14 @@ pub fn library(id: &str) -> Option<(LibraryInfo, Arc<SwatchLibrary>)> {
     Some((infos().nth(i)?, MADE.get(i)?.clone()))
 }
 
-/// The built-in library document that holds pattern `name` (a library panel draws its pattern
-/// swatches from it). Pattern names are unique across the built-in libraries.
-pub fn pattern_source(name: &str) -> Option<Arc<Document>> {
-    PATTERN_LIBRARIES.iter().filter_map(|b| library_doc(b.id)).find(|d| d.pattern(name).is_some())
+/// The built-in library document that holds the pattern of swatch `w`, when `w` is one of a
+/// built-in pattern library's own swatches (a library panel draws them from it). A swatch of
+/// another library is not, even under the same name.
+pub fn swatch_source(w: &Swatch) -> Option<Arc<Document>> {
+    let Paint::Pattern { pattern, .. } = &w.paint else { return None };
+    let own = |lib: &SwatchLibrary| lib.swatches.iter().any(|s| std::ptr::eq(s, w));
+    let b = PATTERN_LIBRARIES.iter().find(|b| library(b.id).is_some_and(|(_, lib)| own(&lib)))?;
+    library_doc(b.id).filter(|d| d.pattern(pattern).is_some())
 }
 
 /// Add pattern `name` of library `lib` to `d` with the resources its art uses, as pasting art

crates/engine/src/tests/swatchlib.rs

@@ -719,10 +719,10 @@ fn pattern_libraries_bring_their_patterns_and_add_each_once() {
 }
 
 /// The built-in pattern libraries: unique, tiling patterns with art, whose names no two libraries
-/// share.
+/// share. Each library's own swatches draw from it; a swatch of the same name elsewhere does not.
 #[test]
 fn built_in_pattern_libraries_hold_tiling_patterns_with_unique_names() {
-    use crate::cmd::patternlib::{PATTERN_LIBRARIES, library_doc, pattern_source};
+    use crate::cmd::patternlib::{PATTERN_LIBRARIES, library, library_doc, swatch_source};
     let mut names = std::collections::HashSet::new();
     for b in PATTERN_LIBRARIES {
         let d = library_doc(b.id).unwrap();
@@ -731,10 +731,13 @@ fn built_in_pattern_libraries_hold_tiling_patterns_with_unique_names() {
             assert!(names.insert(p.name.clone()), "{} is in two libraries", p.name);
             assert!(!p.art.is_empty() && p.width() > 0.0 && p.height() > 0.0, "{}", p.name);
             assert!(vectorcraft_render::render_pattern_swatch(&d, &p.name, 16).is_some(), "{}", p.name);
-            assert!(std::sync::Arc::ptr_eq(&pattern_source(&p.name).unwrap(), &d));
+        }
+        let (_, lib) = library(b.id).unwrap();
+        for w in &lib.swatches {
+            assert!(std::sync::Arc::ptr_eq(&swatch_source(w).unwrap(), &d), "{}", w.name);
+            assert!(swatch_source(&w.clone()).is_none(), "a copy of {} is another library's swatch", w.name);
         }
     }
-    assert!(pattern_source("No Such Pattern").is_none());
 }
 
 /// #3602: a library titled with a Windows device name is saved under a name that is not one.

crates/ui-egui/src/panels/swatches/libraries.rs

@@ -2,8 +2,8 @@ use super::actions::deletable;
 use super::dnd::selection;
 use super::tiles::{describe, global_mark, list_icons, pattern_thumb_in};
 use super::{
-    Arc, BuiltinLibrary, GRADIENT_LIBRARIES, Item, LibraryKind, LibraryRef, PATTERN_LIBRARIES, Paint, Rect, Row, SWATCH_LIBRARIES, Swatch,
-    SwatchLibrary, Ui, Value, VectorcraftApp, json, library_panel, menu_item, patternlib, swatch_tile, swatchlib,
+    Arc, BuiltinLibrary, GRADIENT_LIBRARIES, Item, LibraryKind, LibraryRef, PATTERN_LIBRARIES, Rect, Row, SWATCH_LIBRARIES, Swatch, SwatchLibrary,
+    Ui, Value, VectorcraftApp, json, library_panel, menu_item, patternlib, swatch_tile, swatchlib,
 };
 
 fn library_refs(libs: Vec<swatchlib::LibraryInfo>) -> Vec<LibraryRef> {
@@ -100,9 +100,7 @@ impl LibraryKind for SwatchLibraries {
     fn draw(_: &VectorcraftApp, ui: &Ui, r: Rect, w: &Swatch, selected: bool, hovered: bool) {
         swatch_tile(ui, r, &w.paint, selected, hovered);
         // A built-in pattern library's pattern, drawn from the library.
-        if let Paint::Pattern { pattern, .. } = &w.paint
-            && let Some(src) = patternlib::pattern_source(pattern)
-        {
+        if let Some(src) = patternlib::swatch_source(w) {
             pattern_thumb_in(&src, ui, r.shrink(1.0), &w.paint);
         }
         if w.global {