[librsvg] Replace state.join/state.has_join with an Option

[Federico Mena Quintero <federico src gnome org>]

commit 6ec84c9dacbddb8a5161c63af0a44ab8e60990dc
Author: Federico Mena Quintero <federico gnome org>
Date:   Mon Mar 26 11:40:10 2018 -0600

    Replace state.join/state.has_join with an Option
    
    It's a bit strange that the caller (in draw.rs) needs to
    unwrap_or_default() - we'll refactor this later.

 rsvg_internals/src/draw.rs  |  4 +++-
 rsvg_internals/src/state.rs | 15 +++++----------
 2 files changed, 8 insertions(+), 11 deletions(-)
---
diff --git a/rsvg_internals/src/draw.rs b/rsvg_internals/src/draw.rs
index efea67d1..50656747 100644
--- a/rsvg_internals/src/draw.rs
+++ b/rsvg_internals/src/draw.rs
@@ -126,7 +126,9 @@ fn setup_cr_for_stroke(cr: &cairo::Context, draw_ctx: *mut RsvgDrawingCtx, state
     cr.set_line_width(state::get_stroke_width(state).normalize(draw_ctx));
     cr.set_miter_limit(state::get_miter_limit(state));
     cr.set_line_cap(cairo::LineCap::from(state::get_state_rust(state).cap));
-    cr.set_line_join(cairo::LineJoin::from(state::get_state_rust(state).join));
+    cr.set_line_join(cairo::LineJoin::from(
+        state::get_state_rust(state).join.unwrap_or_default(),
+    ));
 
     let dash = state::get_stroke_dasharray(state);
 
diff --git a/rsvg_internals/src/state.rs b/rsvg_internals/src/state.rs
index e1dd2188..4c5fd02b 100644
--- a/rsvg_internals/src/state.rs
+++ b/rsvg_internals/src/state.rs
@@ -30,8 +30,7 @@ pub enum RsvgState {}
 pub struct State {
     pub affine: cairo::Matrix,
 
-    pub join: StrokeLinejoin,
-    has_join: bool,
+    pub join: Option<StrokeLinejoin>,
 
     pub cap: StrokeLinecap,
     has_cap: bool,
@@ -52,7 +51,6 @@ impl State {
             affine: cairo::Matrix::identity(),
 
             join: Default::default(),
-            has_join: Default::default(),
 
             cap: Default::default(),
             has_cap: Default::default(),
@@ -73,20 +71,17 @@ impl State {
             Attribute::StrokeLinejoin => {
                 match StrokeLinejoin::parse(value, ()) {
                     Ok(StrokeLinejoin::Inherit) => {
-                        self.join = StrokeLinejoin::default();
-                        self.has_join = false;
+                        self.join = None;
                         Ok(())
                     }
 
                     Ok(j) => {
-                        self.join = j;
-                        self.has_join = true;
+                        self.join = Some(j);
                         Ok(())
                     }
 
                     Err(e) => {
-                        self.join = StrokeLinejoin::default();
-                        self.has_join = false; // FIXME - propagate errors instead of defaulting
+                        self.join = None; // FIXME - propagate errors instead of defaulting
                         Err(e)
                     }
                 }
@@ -567,7 +562,7 @@ pub extern "C" fn rsvg_state_rust_inherit_run(
         let dst = &mut *dst;
         let src = &*src;
 
-        if inherit_from_src(inherit_fn, dst.has_join, src.has_join) {
+        if inherit_from_src(inherit_fn, dst.join.is_some(), src.join.is_some()) {
             dst.join = src.join;
         }