[librsvg: 6/9] AcquireError::CircularReference(n) now stores an RsvgNode, not a Fragment

[Federico Mena Quintero <federico src gnome org>]

commit 05b1c3fe745c4c6199f3db2366a4171213d3fb95
Author: Federico Mena Quintero <federico gnome org>
Date:   Tue Oct 15 09:59:13 2019 -0500

    AcquireError::CircularReference(n) now stores an RsvgNode, not a Fragment
    
    We'll add a way for <use> to add itself to the stack of acquired
    nodes, even if it doesn't have a Fragment id associated to it.
    
    This also removes impl Error for AcquiredError; it's not needed, and
    it would complicate things because Error requires Debug, and we can't
    impl Debug on RsvgError because of the orphan rule.

 rsvg_internals/src/drawing_ctx.rs  |  2 +-
 rsvg_internals/src/error.rs        | 21 +++++----------------
 rsvg_internals/src/gradient.rs     |  2 +-
 rsvg_internals/src/paint_server.rs |  3 +--
 rsvg_internals/src/pattern.rs      |  2 +-
 rsvg_internals/src/structure.rs    |  5 ++---
 6 files changed, 11 insertions(+), 24 deletions(-)
---
diff --git a/rsvg_internals/src/drawing_ctx.rs b/rsvg_internals/src/drawing_ctx.rs
index 589ed501..ecb33de9 100644
--- a/rsvg_internals/src/drawing_ctx.rs
+++ b/rsvg_internals/src/drawing_ctx.rs
@@ -1140,7 +1140,7 @@ impl AcquiredNodes {
 
         if node_is_accessed_by_reference(&node) {
             if self.node_stack.borrow().contains(&node) {
-                Err(AcquireError::CircularReference(fragment.clone()))
+                Err(AcquireError::CircularReference(node.clone()))
             } else {
                 self.node_stack.borrow_mut().push(&node);
                 Ok(AcquiredNode {
diff --git a/rsvg_internals/src/error.rs b/rsvg_internals/src/error.rs
index dff26a4e..05c90f99 100644
--- a/rsvg_internals/src/error.rs
+++ b/rsvg_internals/src/error.rs
@@ -11,6 +11,7 @@ use libc;
 use markup5ever::LocalName;
 
 use crate::allowed_url::Fragment;
+use crate::node::RsvgNode;
 use crate::parsers::ParseError;
 
 /// A simple error which refers to an attribute's value
@@ -123,25 +124,13 @@ impl From<cairo::Status> for RenderingError {
     }
 }
 
-#[derive(Debug)]
 pub enum AcquireError {
     LinkNotFound(Fragment),
     InvalidLinkType(Fragment),
-    CircularReference(Fragment),
+    CircularReference(RsvgNode),
     MaxReferencesExceeded,
 }
 
-impl error::Error for AcquireError {
-    fn description(&self) -> &str {
-        match *self {
-            AcquireError::LinkNotFound(_) => "link not found",
-            AcquireError::InvalidLinkType(_) => "link is to object of invalid type",
-            AcquireError::CircularReference(_) => "circular reference in link",
-            AcquireError::MaxReferencesExceeded => "maximum number of references exceeded",
-        }
-    }
-}
-
 impl fmt::Display for AcquireError {
     fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
         match *self {
@@ -151,11 +140,11 @@ impl fmt::Display for AcquireError {
             AcquireError::InvalidLinkType(ref frag) =>
                 write!(f, "link {} is to object of invalid type", frag),
 
-            AcquireError::CircularReference(ref frag) =>
-                write!(f, "circular reference in link {}", frag),
+            AcquireError::CircularReference(ref node) =>
+                write!(f, "circular reference in node {}", node),
 
             AcquireError::MaxReferencesExceeded =>
-                write!(f, "{}", self.description()),
+                write!(f, "maximum number of references exceeded"),
         }
     }
 }
diff --git a/rsvg_internals/src/gradient.rs b/rsvg_internals/src/gradient.rs
index 6e87138f..b4803ffe 100644
--- a/rsvg_internals/src/gradient.rs
+++ b/rsvg_internals/src/gradient.rs
@@ -638,7 +638,7 @@ macro_rules! impl_paint_source {
                         let acquired_node = acquired.get();
 
                         if stack.contains(acquired_node) {
-                            return Err(AcquireError::CircularReference(fragment.clone()));
+                            return Err(AcquireError::CircularReference(acquired_node.clone()));
                         }
 
                         let borrowed_node = acquired_node.borrow();
diff --git a/rsvg_internals/src/paint_server.rs b/rsvg_internals/src/paint_server.rs
index 357d3506..cfc76089 100644
--- a/rsvg_internals/src/paint_server.rs
+++ b/rsvg_internals/src/paint_server.rs
@@ -77,8 +77,7 @@ pub trait PaintSource {
                 resolved.set_as_paint_source(values, draw_ctx, opacity, bbox)
             }
 
-            Err(AcquireError::CircularReference(_)) => {
-                // FIXME: add a fragment or node id to this:
+            Err(AcquireError::CircularReference(node)) => {
                 rsvg_log!("circular reference in paint server {}", node);
                 Err(RenderingError::CircularReference)
             }
diff --git a/rsvg_internals/src/pattern.rs b/rsvg_internals/src/pattern.rs
index 8edf4fe7..dab166b7 100644
--- a/rsvg_internals/src/pattern.rs
+++ b/rsvg_internals/src/pattern.rs
@@ -180,7 +180,7 @@ impl PaintSource for NodePattern {
                         let acquired_node = acquired.get();
 
                         if stack.contains(acquired_node) {
-                            return Err(AcquireError::CircularReference(fragment.clone()));
+                            return Err(AcquireError::CircularReference(acquired_node.clone()));
                         }
 
                         let borrowed_node = acquired_node.borrow();
diff --git a/rsvg_internals/src/structure.rs b/rsvg_internals/src/structure.rs
index 49ea396d..773d1dff 100644
--- a/rsvg_internals/src/structure.rs
+++ b/rsvg_internals/src/structure.rs
@@ -316,9 +316,8 @@ impl NodeTrait for NodeUse {
         let acquired = match draw_ctx.acquire_node(link, &[]) {
             Ok(acquired) => acquired,
 
-            Err(AcquireError::CircularReference(_)) => {
-                // FIXME: add a fragment or node id to this:
-                rsvg_log!("circular reference in <use> element {}", node);
+            Err(AcquireError::CircularReference(node)) => {
+                rsvg_log!("circular reference in element {}", node);
                 return Err(RenderingError::CircularReference);
             }