Fix defs id generation.

crates/usvg/src/parser/clippath.rs

@@ -32,7 +32,8 @@ pub(crate) fn convert(
     // Only `userSpaceOnUse` clipPaths can be shared,
     // because `objectBoundingBox` one will be converted into user one
     // and will become node-specific.
-    if units == Units::UserSpaceOnUse {
+    let cacheable = units == Units::UserSpaceOnUse;
+    if cacheable {
         if let Some(clip) = cache.clip_paths.get(node.element_id()) {
             return Some(clip.clone());
         }
@@ -62,7 +63,12 @@ pub(crate) fn convert(
         }
     }
 
-    let id = NonEmptyString::new(node.element_id().to_string())?;
+    let mut id = NonEmptyString::new(node.element_id().to_string())?;
+    // Generate ID only when we're parsing `objectBoundingBox` clip for the second time.
+    if !cacheable && cache.clip_paths.contains_key(id.get()) {
+        id = cache.gen_clip_path_id();
+    }
+    let id_copy = id.get().to_string();
 
     let mut clip = ClipPath {
         id,
@@ -78,9 +84,7 @@ pub(crate) fn convert(
     if clip.root.has_children() {
         clip.root.calculate_bounding_boxes();
         let clip = Arc::new(clip);
-        cache
-            .clip_paths
-            .insert(node.element_id().to_string(), clip.clone());
+        cache.clip_paths.insert(id_copy, clip.clone());
         Some(clip)
     } else {
         // A clip path without children is invalid.

crates/usvg/src/parser/converter.rs

@@ -46,6 +46,7 @@ pub struct Cache {
     #[cfg(feature = "text")]
     pattern_index: usize,
     clip_path_index: usize,
+    mask_index: usize,
     filter_index: usize,
 }
 
@@ -98,6 +99,17 @@ impl Cache {
         }
     }
 
+    pub(crate) fn gen_mask_id(&mut self) -> NonEmptyString {
+        loop {
+            self.mask_index += 1;
+            let new_id = format!("mask{}", self.mask_index);
+            let new_hash = string_hash(&new_id);
+            if !self.all_ids.contains(&new_hash) {
+                return NonEmptyString::new(new_id).unwrap();
+            }
+        }
+    }
+
     pub(crate) fn gen_filter_id(&mut self) -> NonEmptyString {
         loop {
             self.filter_index += 1;
@@ -275,7 +287,15 @@ pub(crate) fn convert_doc(
 
     for node in svg_doc.descendants() {
         if let Some(tag) = node.tag_name() {
-            if matches!(tag, EId::Filter | EId::ClipPath) {
+            if matches!(
+                tag,
+                EId::ClipPath
+                    | EId::Filter
+                    | EId::LinearGradient
+                    | EId::Mask
+                    | EId::Pattern
+                    | EId::RadialGradient
+            ) {
                 if !node.element_id().is_empty() {
                     cache.all_ids.insert(string_hash(node.element_id()));
                 }

crates/usvg/src/parser/filter.rs

@@ -176,7 +176,8 @@ fn convert_url(
     // Only `userSpaceOnUse` clipPaths can be shared,
     // because `objectBoundingBox` one will be converted into user one
     // and will become node-specific.
-    if units == Units::UserSpaceOnUse && primitive_units == Units::UserSpaceOnUse {
+    let cacheable = units == Units::UserSpaceOnUse && primitive_units == Units::UserSpaceOnUse;
+    if cacheable {
         if let Some(filter) = cache.filters.get(node.element_id()) {
             return Ok(Some(filter.clone()));
         }
@@ -247,17 +248,20 @@ fn convert_url(
         return Err(());
     }
 
-    let id = NonEmptyString::new(node.element_id().to_string()).ok_or(())?;
+    let mut id = NonEmptyString::new(node.element_id().to_string()).ok_or(())?;
+    // Generate ID only when we're parsing `objectBoundingBox` filter for the second time.
+    if !cacheable && cache.filters.contains_key(id.get()) {
+        id = cache.gen_filter_id();
+    }
+    let id_copy = id.get().to_string();
 
     let filter = Arc::new(Filter {
         id,
         rect,
         primitives,
     });
 
-    cache
-        .filters
-        .insert(node.element_id().to_string(), filter.clone());
+    cache.filters.insert(id_copy, filter.clone());
 
     Ok(Some(filter))
 }

crates/usvg/src/parser/image.rs

@@ -191,11 +191,14 @@ pub(crate) fn convert(node: SvgNode, state: &converter::State, parent: &mut Grou
         Length::new_number(actual_size.height() as f64),
     );
 
-    match (node.attribute::<Length>(AId::Width), node.attribute::<Length>(AId::Height)) {
+    match (
+        node.attribute::<Length>(AId::Width),
+        node.attribute::<Length>(AId::Height),
+    ) {
         (Some(_), None) => {
             // Only width was defined, so we need to scale height accordingly.
             height = actual_size.height() * (width / actual_size.width());
-        },
+        }
         (None, Some(_)) => {
             // Only height was defined, so we need to scale width accordingly.
             width = actual_size.width() * (height / actual_size.height());

crates/usvg/src/parser/mask.rs

@@ -34,14 +34,13 @@ pub(crate) fn convert(
     // Only `userSpaceOnUse` masks can be shared,
     // because `objectBoundingBox` one will be converted into user one
     // and will become node-specific.
-    if units == Units::UserSpaceOnUse && content_units == Units::UserSpaceOnUse {
+    let cacheable = units == Units::UserSpaceOnUse && content_units == Units::UserSpaceOnUse;
+    if cacheable {
         if let Some(mask) = cache.masks.get(node.element_id()) {
             return Some(mask.clone());
         }
     }
 
-    let id = NonEmptyString::new(node.element_id().to_string())?;
-
     let rect = NonZeroRect::from_xywh(
         node.convert_length(AId::X, units, state, Length::new(-10.0, Unit::Percent)),
         node.convert_length(AId::Y, units, state, Length::new(-10.0, Unit::Percent)),
@@ -63,15 +62,23 @@ pub(crate) fn convert(
         }
     }
 
+    let mut id = NonEmptyString::new(node.element_id().to_string())?;
+    // Generate ID only when we're parsing `objectBoundingBox` mask for the second time.
+    if !cacheable && cache.masks.contains_key(id.get()) {
+        id = cache.gen_mask_id();
+    }
+    let id_copy = id.get().to_string();
+
     if mask_all {
-        let mask = Mask {
+        let mask = Arc::new(Mask {
             id,
             rect,
             kind: MaskType::Luminance,
             mask: None,
             root: Group::empty(),
-        };
-        return Some(Arc::new(mask));
+        });
+        cache.masks.insert(id_copy, mask.clone());
+        return Some(mask);
     }
 
     // Resolve linked mask.
@@ -139,8 +146,6 @@ pub(crate) fn convert(
     mask.root.calculate_bounding_boxes();
 
     let mask = Arc::new(mask);
-    cache
-        .masks
-        .insert(node.element_id().to_string(), mask.clone());
+    cache.masks.insert(id_copy, mask.clone());
     Some(mask)
 }

crates/usvg/tests/write.rs

@@ -95,6 +95,11 @@ fn filter_id_with_prefix() {
     resave_with_prefix("filter-id-with-prefix", "prefix-");
 }
 
+#[test]
+fn filter_with_object_units_multi_use() {
+    resave("filter-with-object-units-multi-use");
+}
+
 #[test]
 fn preserve_id_clip_path_v1() {
     resave("preserve-id-clip-path-v1");
@@ -125,6 +130,16 @@ fn clip_path_with_complex_text() {
     resave("clip-path-with-complex-text");
 }
 
+#[test]
+fn clip_path_with_object_units_multi_use() {
+    resave("clip-path-with-object-units-multi-use");
+}
+
+#[test]
+fn mask_with_object_units_multi_use() {
+    resave("mask-with-object-units-multi-use");
+}
+
 #[test]
 fn text_with_generated_gradients() {
     resave("text-with-generated-gradients");