[librsvg] Parse <style> contents directly DocumentBuilder at the time of append_characters

[Federico Mena Quintero <federico src gnome org>]

commit e219c3a209c6a55d6f8a765d5685e9c431de6ce0
Author: Federico Mena Quintero <federico gnome org>
Date:   Fri Nov 1 13:35:31 2019 -0600

    Parse <style> contents directly DocumentBuilder at the time of append_characters
    
    That is, don't create a Chars node with the contents of the
    stylesheet; just parse it directly.

 rsvg_internals/src/document.rs | 13 ++++++++++++-
 rsvg_internals/src/style.rs    | 21 +++------------------
 rsvg_internals/src/text.rs     |  4 ----
 rsvg_internals/src/xml.rs      | 14 +-------------
 4 files changed, 16 insertions(+), 36 deletions(-)
---
diff --git a/rsvg_internals/src/document.rs b/rsvg_internals/src/document.rs
index d4017565..f65e2abc 100644
--- a/rsvg_internals/src/document.rs
+++ b/rsvg_internals/src/document.rs
@@ -16,6 +16,7 @@ use crate::node::{NodeCascade, NodeData, NodeType, RsvgNode};
 use crate::properties::ComputedValues;
 use crate::property_bag::PropertyBag;
 use crate::structure::{IntrinsicDimensions, Svg};
+use crate::style::Style;
 use crate::surface_utils::shared_surface::SharedImageSurface;
 use crate::text::NodeChars;
 use crate::xml::xml_load_from_possibly_compressed_stream;
@@ -279,6 +280,16 @@ impl DocumentBuilder {
             return;
         }
 
+        if parent.borrow().get_type() == NodeType::Style {
+            if parent.borrow().get_impl::<Style>().is_text_css() {
+                self.parse_css(text);
+            }
+        } else {
+            self.append_chars_to_parent(text, parent);
+        }
+    }
+
+    fn append_chars_to_parent(&mut self, text: &str, parent: &mut RsvgNode) {
         // When the last child is a Chars node we can coalesce
         // the text and avoid screwing up the Pango layouts
         let chars_node = if let Some(child) = parent
@@ -312,7 +323,7 @@ impl DocumentBuilder {
             .map_err(|_| LoadingError::BadUrl)
     }
 
-    pub fn parse_css(&mut self, css_data: &str) {
+    fn parse_css(&mut self, css_data: &str) {
         self.css_rules
             .parse(self.load_options.base_url.as_ref(), css_data);
     }
diff --git a/rsvg_internals/src/style.rs b/rsvg_internals/src/style.rs
index 07d4cb53..59247a83 100644
--- a/rsvg_internals/src/style.rs
+++ b/rsvg_internals/src/style.rs
@@ -1,8 +1,7 @@
 use markup5ever::{expanded_name, local_name, namespace_url, ns};
 
-use crate::node::{NodeResult, NodeTrait, NodeType, RsvgNode};
+use crate::node::{NodeResult, NodeTrait, RsvgNode};
 use crate::property_bag::PropertyBag;
-use crate::text::NodeChars;
 
 /// Represents a <style> node.
 ///
@@ -14,7 +13,7 @@ pub struct Style {
 }
 
 impl Style {
-    pub fn get_css(&self, node: &RsvgNode) -> String {
+    pub fn is_text_css(&self) -> bool {
         // FIXME: See these:
         //
         // https://www.w3.org/TR/SVG11/styling.html#StyleElementTypeAttribute
@@ -24,21 +23,7 @@ impl Style {
         // "contentStyleType" attribute of the svg element, which in turn
         // defaults to "text/css".
 
-        let have_css = self.type_.as_ref().map(|t| t == "text/css").unwrap_or(true);
-
-        if have_css {
-            node.children()
-                .filter_map(|child| {
-                    if child.borrow().get_type() == NodeType::Chars {
-                        Some(child.borrow().get_impl::<NodeChars>().get_string())
-                    } else {
-                        None
-                    }
-                })
-                .collect::<String>()
-        } else {
-            "".to_string()
-        }
+        self.type_.as_ref().map(|t| t == "text/css").unwrap_or(true)
     }
 }
 
diff --git a/rsvg_internals/src/text.rs b/rsvg_internals/src/text.rs
index 47657ce0..e21aad91 100644
--- a/rsvg_internals/src/text.rs
+++ b/rsvg_internals/src/text.rs
@@ -499,10 +499,6 @@ impl NodeChars {
         }
     }
 
-    pub fn get_string(&self) -> String {
-        self.string.borrow().clone()
-    }
-
     pub fn append(&self, s: &str) {
         self.string.borrow_mut().push_str(s);
         *self.space_normalized.borrow_mut() = None;
diff --git a/rsvg_internals/src/xml.rs b/rsvg_internals/src/xml.rs
index 39d13fa2..fbff54e2 100644
--- a/rsvg_internals/src/xml.rs
+++ b/rsvg_internals/src/xml.rs
@@ -13,9 +13,8 @@ use crate::document::{Document, DocumentBuilder};
 use crate::error::LoadingError;
 use crate::io::{self, get_input_stream_for_loading};
 use crate::limits::MAX_LOADED_ELEMENTS;
-use crate::node::{NodeType, RsvgNode};
+use crate::node::RsvgNode;
 use crate::property_bag::PropertyBag;
-use crate::style::Style;
 use crate::xml2_load::{ParseFromStreamError, Xml2Parser};
 
 #[derive(Clone)]
@@ -286,18 +285,7 @@ impl XmlState {
 
     fn element_creation_end_element(&self) {
         let mut inner = self.inner.borrow_mut();
-
         let node = inner.current_node.take().unwrap();
-
-        if node.borrow().get_type() == NodeType::Style {
-            let css_data = node.borrow().get_impl::<Style>().get_css(&node);
-            inner
-                .document_builder
-                .as_mut()
-                .unwrap()
-                .parse_css(&css_data);
-        }
-
         inner.current_node = node.parent();
     }