[librsvg] property_bag.rs: Turn lookup_length() into length_or_default(); return errors

[Federico Mena Quintero <federico src gnome org>]

commit 61c355cb22064e331228dc389500da447be6a900
Author: Federico Mena Quintero <federico gnome org>
Date:   Wed Mar 15 22:42:57 2017 -0600

    property_bag.rs: Turn lookup_length() into length_or_default(); return errors
    
    We used to return an RsvgLength with a default value in case of error.
    
    Now we actually return a Result.

 rust/src/marker.rs       |    4 ++--
 rust/src/property_bag.rs |    8 +++-----
 rust/src/shapes.rs       |   30 +++++++++++++++---------------
 3 files changed, 20 insertions(+), 22 deletions(-)
---
diff --git a/rust/src/marker.rs b/rust/src/marker.rs
index 8a5ca00..42cc77b 100644
--- a/rust/src/marker.rs
+++ b/rust/src/marker.rs
@@ -215,8 +215,8 @@ impl NodeTrait for NodeMarker {
     fn set_atts (&self, _: &RsvgNode, _: *const RsvgHandle, pbag: *const RsvgPropertyBag) -> NodeResult {
         self.units.set (property_bag::lookup_and_parse (pbag, "markerUnits"));
 
-        self.ref_x.set (property_bag::lookup_length (pbag, "refX", LengthDir::Horizontal));
-        self.ref_y.set (property_bag::lookup_length (pbag, "refY", LengthDir::Vertical));
+        self.ref_x.set (property_bag::length_or_default (pbag, "refX", LengthDir::Horizontal)?);
+        self.ref_y.set (property_bag::length_or_default (pbag, "refY", LengthDir::Vertical)?);
 
         self.width.set (property_bag::lookup (pbag, "markerWidth").map_or (NodeMarker::get_default_size (),
                                                                            |v| RsvgLength::parse (&v, 
LengthDir::Horizontal).unwrap_or (NodeMarker::get_default_size ())));
diff --git a/rust/src/property_bag.rs b/rust/src/property_bag.rs
index 676db6d..d8801d8 100644
--- a/rust/src/property_bag.rs
+++ b/rust/src/property_bag.rs
@@ -44,15 +44,13 @@ pub fn lookup_and_parse<T: Default + FromStr> (pbag: *const RsvgPropertyBag, key
     }
 }
 
-pub fn lookup_length (pbag: *const RsvgPropertyBag, key: &str, length_dir: LengthDir) -> RsvgLength {
+pub fn length_or_default (pbag: *const RsvgPropertyBag, key: &'static str, length_dir: LengthDir) -> Result 
<RsvgLength, NodeError> {
     let value = lookup (pbag, key);
 
     if let Some (v) = value {
-
-        // FIXME: Error is discarded here.  Figure out a way to propagate it upstream.
-        RsvgLength::parse (&v, length_dir).unwrap_or (RsvgLength::default ())
+        RsvgLength::parse (&v, length_dir).map_err (|e| NodeError::attribute_error (key, e))
     } else {
-        RsvgLength::default ()
+        Ok (RsvgLength::default ())
     }
 }
 
diff --git a/rust/src/shapes.rs b/rust/src/shapes.rs
index 1e9f4d0..e960f20 100644
--- a/rust/src/shapes.rs
+++ b/rust/src/shapes.rs
@@ -200,10 +200,10 @@ impl NodeLine {
 
 impl NodeTrait for NodeLine {
     fn set_atts (&self, _: &RsvgNode, _: *const RsvgHandle, pbag: *const RsvgPropertyBag) -> NodeResult {
-        self.x1.set (property_bag::lookup_length (pbag, "x1", LengthDir::Horizontal));
-        self.y1.set (property_bag::lookup_length (pbag, "y1", LengthDir::Vertical));
-        self.x2.set (property_bag::lookup_length (pbag, "x2", LengthDir::Horizontal));
-        self.y2.set (property_bag::lookup_length (pbag, "y2", LengthDir::Vertical));
+        self.x1.set (property_bag::length_or_default (pbag, "x1", LengthDir::Horizontal)?);
+        self.y1.set (property_bag::length_or_default (pbag, "y1", LengthDir::Vertical)?);
+        self.x2.set (property_bag::length_or_default (pbag, "x2", LengthDir::Horizontal)?);
+        self.y2.set (property_bag::length_or_default (pbag, "y2", LengthDir::Vertical)?);
 
         Ok (())
     }
@@ -257,10 +257,10 @@ impl NodeRect {
 
 impl NodeTrait for NodeRect {
     fn set_atts (&self, _: &RsvgNode, _: *const RsvgHandle, pbag: *const RsvgPropertyBag) -> NodeResult {
-        self.x.set (property_bag::lookup_length (pbag, "x", LengthDir::Horizontal));
-        self.y.set (property_bag::lookup_length (pbag, "y", LengthDir::Vertical));
-        self.w.set (property_bag::lookup_length (pbag, "width", LengthDir::Horizontal));
-        self.h.set (property_bag::lookup_length (pbag, "height", LengthDir::Vertical));
+        self.x.set (property_bag::length_or_default (pbag, "x", LengthDir::Horizontal)?);
+        self.y.set (property_bag::length_or_default (pbag, "y", LengthDir::Vertical)?);
+        self.w.set (property_bag::length_or_default (pbag, "width", LengthDir::Horizontal)?);
+        self.h.set (property_bag::length_or_default (pbag, "height", LengthDir::Vertical)?);
 
         let v = property_bag::lookup (pbag, "rx");
         if let Some (val) = v {
@@ -445,9 +445,9 @@ impl NodeCircle {
 
 impl NodeTrait for NodeCircle {
     fn set_atts (&self, _: &RsvgNode, _: *const RsvgHandle, pbag: *const RsvgPropertyBag) -> NodeResult {
-        self.cx.set (property_bag::lookup_length (pbag, "cx", LengthDir::Horizontal));
-        self.cy.set (property_bag::lookup_length (pbag, "cy", LengthDir::Vertical));
-        self.r.set  (property_bag::lookup_length (pbag, "r", LengthDir::Both));
+        self.cx.set (property_bag::length_or_default (pbag, "cx", LengthDir::Horizontal)?);
+        self.cy.set (property_bag::length_or_default (pbag, "cy", LengthDir::Vertical)?);
+        self.r.set  (property_bag::length_or_default (pbag, "r", LengthDir::Both)?);
 
         Ok (())
     }
@@ -487,10 +487,10 @@ impl NodeEllipse {
 
 impl NodeTrait for NodeEllipse {
     fn set_atts (&self, _: &RsvgNode, _: *const RsvgHandle, pbag: *const RsvgPropertyBag) -> NodeResult {
-        self.cx.set (property_bag::lookup_length (pbag, "cx", LengthDir::Horizontal));
-        self.cy.set (property_bag::lookup_length (pbag, "cy", LengthDir::Vertical));
-        self.rx.set (property_bag::lookup_length (pbag, "rx", LengthDir::Horizontal));
-        self.ry.set (property_bag::lookup_length (pbag, "ry", LengthDir::Vertical));
+        self.cx.set (property_bag::length_or_default (pbag, "cx", LengthDir::Horizontal)?);
+        self.cy.set (property_bag::length_or_default (pbag, "cy", LengthDir::Vertical)?);
+        self.rx.set (property_bag::length_or_default (pbag, "rx", LengthDir::Horizontal)?);
+        self.ry.set (property_bag::length_or_default (pbag, "ry", LengthDir::Vertical)?);
 
         Ok (())
     }