Merge pull request #6576 from dotCooCoo/fix/pasted-svg-filter-size-limit

Effects: a pasted SVG filter at the size limit still draws under its new name

crates/engine/src/cmd/clipboard/resources.rs

@@ -1219,7 +1219,9 @@ impl Clipboard {
     /// How the pasted SVG filter effects relink ([`Relink::filters`]). Each names the document's
     /// filter of its name; one that draws another definition than that filter takes the document's
     /// filter when pasted back into the document it came from, and elsewhere keeps its own under a
-    /// free name, so editing or deleting the document's filter leaves it alone.
+    /// free name, so editing or deleting the document's filter leaves it alone. When that name would
+    /// make the filter too long to draw, the free name is a shorter start of its name ("Shif"), else
+    /// a free letter or digit; the filter's id is always its name.
     fn filter_links(&self, d: &Document, same_doc: bool) -> BTreeMap<(String, String), (String, String)> {
         let mut found = BTreeSet::new();
         for n in &self.nodes {
@@ -1244,9 +1246,20 @@ impl Clipboard {
             let to = if same_doc {
                 (name.clone(), held.xml.clone())
             } else {
-                let new = unique_name(&name, |n| taken.contains(n));
+                // Free names made from the starts of the name, longest first, then free letters and
+                // digits: the first under which the filter still draws.
+                let mut ends: Vec<usize> = name.char_indices().map(|(i, _)| i).skip(1).collect();
+                ends.push(name.len());
+                let starts = ends.iter().rev().filter_map(|&end| name.get(..end).map(str::trim_end)).filter(|b| !b.is_empty());
+                let shorter = starts.map(|b| unique_name(b, |n| taken.contains(n)));
+                let single = ('a'..='z').chain('0'..='9').map(String::from).filter(|n| !taken.contains(n));
+                let renamed = shorter.chain(single).find_map(|new| {
+                    let drawn = vectorcraft_render::effects::svg_filter::with_id(&xml, &new)
+                        .filter(|x| vectorcraft_render::effects::svg_filter::check(x).is_ok())?;
+                    Some((new, drawn))
+                });
+                let Some((new, drawn)) = renamed else { continue };
                 taken.insert(new.clone());
-                let drawn = vectorcraft_render::effects::svg_filter::with_id(&xml, &new).unwrap_or_else(|| xml.clone());
                 (new, drawn)
             };
             links.insert((name, xml), to);

crates/engine/src/tests/svgfilter.rs

@@ -259,6 +259,31 @@ fn pasted_art_keeps_a_filter_another_of_its_name_would_replace() {
     assert_eq!(both, [("Shift".to_string(), SHIFT_MORE.to_string()), ("Shift".to_string(), SHIFT_MORE.to_string())]);
 }
 
+/// A pasted filter at the size limit, which "Shift 2" would make too long to draw, keeps its own
+/// definition under a free name no longer than its own (a free letter for a one-letter name), and
+/// its id is that name.
+#[test]
+fn pasted_art_with_a_filter_at_the_size_limit_still_draws_when_renamed() {
+    for (name, held, renamed) in [("Shift", SHIFT, "Shif"), ("S", r#"<filter id="S"><feOffset dx="3" dy="3"/></filter>"#, "a")] {
+        let mut s = session();
+        run(&mut s, "svgFilter.define", json!({"xml": held}));
+        let (open, close) = (format!(r#"<filter id="{name}"><feOffset dx="9" dy="9" result=""#), r#""/></filter>"#);
+        let big = format!("{open}{}{close}", "a".repeat(vectorcraft_doc::SvgFilter::MAX_XML - open.len() - close.len()));
+        assert!(vectorcraft_render::effects::svg_filter::check(&big).is_ok());
+        let svg = format!(
+            r#"<svg xmlns="http://www.w3.org/2000/svg" width="100" height="100"><defs>{big}</defs><rect width="30" height="30" filter="url(#{name})"/></svg>"#
+        );
+        run(&mut s, "clipboard.importSvg", json!({"svg": svg}));
+        run(&mut s, "edit.pasteInPlace", json!({}));
+        let pasted = filter_effects(&s);
+        assert_eq!(pasted.len(), 1);
+        assert_eq!(pasted[0].0, renamed, "renamed: {}", pasted[0].0);
+        assert_eq!(vectorcraft_render::effects::svg_filter::check(&pasted[0].1), Ok(renamed.to_string()), "the pasted filter draws under its name");
+        assert!(pasted[0].1.contains("dx=\"9\""), "its own filter");
+        assert_eq!(names(&mut s), [name]);
+    }
+}
+
 /// Art in a symbol's definition that uses a filter follows its edits too.
 #[test]
 fn a_symbols_art_follows_a_filter_edit() {