[librsvg: 1/2] Change Chars::new() to take an initial text

[Federico Mena Quintero <federico src gnome org>]

commit 476cf50e20874c1cd3b79fa54bef8ad0b1465c69
Author: Sven Neumann <sven svenfoo org>
Date:   Mon Aug 24 12:07:33 2020 +0200

    Change Chars::new() to take an initial text
    
    This simplifies the single caller in document.rs.

 rsvg_internals/src/document.rs | 10 +++-------
 rsvg_internals/src/node.rs     |  4 ++--
 rsvg_internals/src/text.rs     | 31 +++++++++++++++++++++++--------
 3 files changed, 28 insertions(+), 17 deletions(-)
---
diff --git a/rsvg_internals/src/document.rs b/rsvg_internals/src/document.rs
index f504ef137..59e46291e 100644
--- a/rsvg_internals/src/document.rs
+++ b/rsvg_internals/src/document.rs
@@ -436,15 +436,11 @@ impl DocumentBuilder {
     fn append_chars_to_parent(&mut self, text: &str, parent: &mut Node) {
         // 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.last_child().filter(|c| c.is_chars()) {
-            child
+        if let Some(child) = parent.last_child().filter(|c| c.is_chars()) {
+            child.borrow_chars().append(text);
         } else {
-            let child = Node::new(NodeData::new_chars());
-            parent.append(child.clone());
-            child
+            parent.append(Node::new(NodeData::new_chars(text)));
         };
-
-        chars_node.borrow_chars().append(text);
     }
 
     pub fn resolve_href(&self, href: &str) -> Result<AllowedUrl, AllowedUrlError> {
diff --git a/rsvg_internals/src/node.rs b/rsvg_internals/src/node.rs
index a6bdd8503..7bcdd566c 100644
--- a/rsvg_internals/src/node.rs
+++ b/rsvg_internals/src/node.rs
@@ -72,8 +72,8 @@ impl NodeData {
         NodeData::Element(Element::new(name, pbag))
     }
 
-    pub fn new_chars() -> NodeData {
-        NodeData::Text(Chars::new())
+    pub fn new_chars(initial_text: &str) -> NodeData {
+        NodeData::Text(Chars::new(initial_text))
     }
 }
 
diff --git a/rsvg_internals/src/text.rs b/rsvg_internals/src/text.rs
index 61d1e0f11..a1c566de0 100644
--- a/rsvg_internals/src/text.rs
+++ b/rsvg_internals/src/text.rs
@@ -484,15 +484,16 @@ fn children_to_chunks(
 /// `xml:space="preserve"` attribute.  A `Chars` stores the characters verbatim
 /// as they come out of the XML parser, after ensuring that they are valid UTF-8.
 
+#[derive(Default)]
 pub struct Chars {
     string: RefCell<String>,
     space_normalized: RefCell<Option<String>>,
 }
 
 impl Chars {
-    pub fn new() -> Chars {
+    pub fn new(initial_text: &str) -> Chars {
         Chars {
-            string: RefCell::new(String::new()),
+            string: RefCell::new(String::from(initial_text)),
             space_normalized: RefCell::new(None),
         }
     }
@@ -564,12 +565,6 @@ impl Chars {
     }
 }
 
-impl Default for Chars {
-    fn default() -> Self {
-        Self::new()
-    }
-}
-
 #[derive(Default)]
 pub struct Text {
     x: Length<Horizontal>,
@@ -1014,3 +1009,23 @@ fn create_pango_layout(
 
     layout
 }
+
+#[cfg(test)]
+mod tests {
+    use super::Chars;
+
+    #[test]
+    fn chars_default() {
+        let c = Chars::default();
+        assert!(c.is_empty());
+        assert!(c.space_normalized.borrow().is_none());
+    }
+
+    #[test]
+    fn chars_new() {
+        let example = "Test 123";
+        let c = Chars::new(example);
+        assert_eq!(c.get_string(), example);
+        assert!(c.space_normalized.borrow().is_none());
+    }
+}