Move all the logic for XML processing instructions to the XML module

I.e. load the xml-stylesheet there, instead of having a
DocumentBuilder::append_stylesheet_from_xml_processing_instruction().

Part-of: <https://gitlab.gnome.org/GNOME/librsvg/-/merge_requests/738>

2 files changed, 21 insertions, 27 deletions

diff --git a/src/document.rs b/src/document.rs
index 190d6fa4..569eb312 100644
--- a/src/document.rs
+++ b/src/document.rs
@@ -543,23 +543,6 @@ impl DocumentBuilder {
         self.stylesheets.push(stylesheet);
     }
 
-    pub fn append_stylesheet_from_xml_processing_instruction(
-        &mut self,
-        href: &str,
-    ) -> Result<(), LoadingError> {
-        let aurl = self
-            .load_options
-            .url_resolver
-            .resolve_href(href)
-            .map_err(|_| LoadingError::BadUrl)?;
-
-        if let Ok(stylesheet) = Stylesheet::from_href(&aurl, Origin::Author, self.session.clone()) {
-            self.append_stylesheet(stylesheet);
-        }
-
-        Ok(())
-    }
-
     /// Creates an element of the specified `name` as a child of `parent`.
     ///
     /// This is the main function to create new SVG elements while parsing XML.
diff --git a/src/xml/mod.rs b/src/xml/mod.rs
index ac4529bc..da9788d4 100644
--- a/src/xml/mod.rs
+++ b/src/xml/mod.rs
@@ -20,6 +20,7 @@ use std::sync::Arc;
 use xml5ever::tendril::format_tendril;
 use xml5ever::tokenizer::{TagKind, Token, TokenSink, XmlTokenizer, XmlTokenizerOpts};
 
+use crate::css::{Origin, Stylesheet};
 use crate::document::{Document, DocumentBuilder};
 use crate::error::{ImplementationLimit, LoadingError};
 use crate::handle::LoadOptions;
@@ -283,18 +284,28 @@ impl XmlState {
             }
 
             if let Some(href) = href {
-                // FIXME: https://www.w3.org/TR/xml-stylesheet/ does not seem to specify
-                // what to do if the stylesheet cannot be loaded, so here we ignore the error.
-                if inner
-                    .document_builder
-                    .as_mut()
-                    .unwrap()
-                    .append_stylesheet_from_xml_processing_instruction(&href)
-                    .is_err()
-                {
+                if let Ok(aurl) = self.load_options.url_resolver.resolve_href(&href) {
+                    if let Ok(stylesheet) =
+                        Stylesheet::from_href(&aurl, Origin::Author, session.clone())
+                    {
+                        inner
+                            .document_builder
+                            .as_mut()
+                            .unwrap()
+                            .append_stylesheet(stylesheet);
+                    } else {
+                        // FIXME: https://www.w3.org/TR/xml-stylesheet/ does not seem to specify
+                        // what to do if the stylesheet cannot be loaded, so here we ignore the error.
+                        rsvg_log!(
+                            session,
+                            "could not create stylesheet from {} in XML processing instruction",
+                            href
+                        );
+                    }
+                } else {
                     rsvg_log!(
                         session,
-                        "invalid xml-stylesheet {} in XML processing instruction",
+                        "{} not allowed for xml-stylesheet in XML processing instruction",
                         href
                     );
                 }