[librsvg/librsvg-2.44] Minimal docs for AttributeError and NodeError

[Federico Mena Quintero <federico src gnome org>]

commit f7f156a49591e9399628b38b4409313bb3147272
Author: Federico Mena Quintero <federico gnome org>
Date:   Fri Sep 14 08:29:36 2018 -0500

    Minimal docs for AttributeError and NodeError

 rsvg_internals/src/error.rs | 6 ++++--
 1 file changed, 4 insertions(+), 2 deletions(-)
---
diff --git a/rsvg_internals/src/error.rs b/rsvg_internals/src/error.rs
index aa5d0fd5..ec30b8f1 100644
--- a/rsvg_internals/src/error.rs
+++ b/rsvg_internals/src/error.rs
@@ -7,15 +7,17 @@ use cssparser::BasicParseError;
 use attributes::Attribute;
 use parsers::ParseError;
 
+/// A simple error which refers to an attribute's value
 #[derive(Debug, Clone, PartialEq)]
 pub enum AttributeError {
-    // parse error
+    /// The value could not be parsed
     Parse(ParseError),
 
-    // invalid value
+    // The value could be parsed, but is invalid
     Value(String),
 }
 
+/// A complete error for an attribute and its erroneous value
 #[derive(Debug, Clone, PartialEq)]
 pub struct NodeError {
     attr: Attribute,