[librsvg] (#268) - Remove the comp-op property; it's not in SVG 1.1 not SVG 2

[Federico Mena Quintero <federico src gnome org>]

commit e300273cb85d2259a39a34a455795aa79d9f8152
Author: Federico Mena Quintero <federico gnome org>
Date:   Mon Jan 14 08:36:41 2019 -0600

    (#268) - Remove the comp-op property; it's not in SVG 1.1 not SVG 2
    
    This property for the compositing operator was just in the SVG 1.2
    spec, which was never implemented.  SVG 2 removed it.
    
    Fixes https://gitlab.gnome.org/GNOME/librsvg/issues/268

 rsvg_internals/build.rs           |  1 -
 rsvg_internals/src/drawing_ctx.rs | 36 ----------------------------------
 rsvg_internals/src/image.rs       |  2 --
 rsvg_internals/src/state.rs       | 41 ---------------------------------------
 4 files changed, 80 deletions(-)
---
diff --git a/rsvg_internals/build.rs b/rsvg_internals/build.rs
index 567ac0b7..ca7e6f22 100644
--- a/rsvg_internals/build.rs
+++ b/rsvg_internals/build.rs
@@ -27,7 +27,6 @@ fn generate_phf_of_svg_attributes() {
         ( "clipPathUnits",      "ClipPathUnits" ),
         ( "color",              "Color" ),
         ( "color-interpolation-filters", "ColorInterpolationFilters" ),
-        ( "comp-op",            "CompOp" ),
         ( "cx",                 "Cx" ),
         ( "cy",                 "Cy" ),
         ( "d",                  "D" ),
diff --git a/rsvg_internals/src/drawing_ctx.rs b/rsvg_internals/src/drawing_ctx.rs
index d76dda79..a5116d39 100644
--- a/rsvg_internals/src/drawing_ctx.rs
+++ b/rsvg_internals/src/drawing_ctx.rs
@@ -21,7 +21,6 @@ use pattern::NodePattern;
 use rect::RectangleExt;
 use state::{
     ClipRule,
-    CompOp,
     ComputedValues,
     EnableBackground,
     FillRule,
@@ -348,7 +347,6 @@ impl DrawingCtx {
             };
 
             let UnitInterval(opacity) = values.opacity.0;
-            let comp_op = values.comp_op;
             let enable_background = values.enable_background;
 
             let affine = original_cr.get_matrix();
@@ -388,7 +386,6 @@ impl DrawingCtx {
                 && filter.is_none()
                 && mask.is_none()
                 && clip_in_object_space.is_none()
-                && comp_op == CompOp::SrcOver
                 && enable_background == EnableBackground::Accumulate);
 
             if needs_temporary_surface {
@@ -441,8 +438,6 @@ impl DrawingCtx {
                         })?;
                 }
 
-                original_cr.set_operator(cairo::Operator::from(comp_op));
-
                 if let Some(mask) = mask {
                     if let Some(acquired) =
                         self.get_acquired_node_of_type(Some(mask), NodeType::Mask)
@@ -881,37 +876,6 @@ impl From<StrokeLinecap> for cairo::LineCap {
     }
 }
 
-impl From<CompOp> for cairo::Operator {
-    fn from(op: CompOp) -> cairo::Operator {
-        match op {
-            CompOp::Clear => cairo::Operator::Clear,
-            CompOp::Src => cairo::Operator::Source,
-            CompOp::Dst => cairo::Operator::Dest,
-            CompOp::SrcOver => cairo::Operator::Over,
-            CompOp::DstOver => cairo::Operator::DestOver,
-            CompOp::SrcIn => cairo::Operator::In,
-            CompOp::DstIn => cairo::Operator::DestIn,
-            CompOp::SrcOut => cairo::Operator::Out,
-            CompOp::DstOut => cairo::Operator::DestOut,
-            CompOp::SrcAtop => cairo::Operator::Atop,
-            CompOp::DstAtop => cairo::Operator::DestAtop,
-            CompOp::Xor => cairo::Operator::Xor,
-            CompOp::Plus => cairo::Operator::Add,
-            CompOp::Multiply => cairo::Operator::Multiply,
-            CompOp::Screen => cairo::Operator::Screen,
-            CompOp::Overlay => cairo::Operator::Overlay,
-            CompOp::Darken => cairo::Operator::Darken,
-            CompOp::Lighten => cairo::Operator::Lighten,
-            CompOp::ColorDodge => cairo::Operator::ColorDodge,
-            CompOp::ColorBurn => cairo::Operator::ColorBurn,
-            CompOp::HardLight => cairo::Operator::HardLight,
-            CompOp::SoftLight => cairo::Operator::SoftLight,
-            CompOp::Difference => cairo::Operator::Difference,
-            CompOp::Exclusion => cairo::Operator::Exclusion,
-        }
-    }
-}
-
 impl From<ClipRule> for cairo::FillRule {
     fn from(c: ClipRule) -> cairo::FillRule {
         match c {
diff --git a/rsvg_internals/src/image.rs b/rsvg_internals/src/image.rs
index 6aa5802f..6a60dc6d 100644
--- a/rsvg_internals/src/image.rs
+++ b/rsvg_internals/src/image.rs
@@ -157,8 +157,6 @@ impl NodeTrait for NodeImage {
                 let x = x * width / w;
                 let y = y * height / h;
 
-                cr.set_operator(cairo::Operator::from(values.comp_op));
-
                 // We need to set extend appropriately, so can't use cr.set_source_surface().
                 //
                 // If extend is left at its default value (None), then bilinear scaling uses
diff --git a/rsvg_internals/src/state.rs b/rsvg_internals/src/state.rs
index 870adf60..c38ee07e 100644
--- a/rsvg_internals/src/state.rs
+++ b/rsvg_internals/src/state.rs
@@ -90,7 +90,6 @@ pub struct SpecifiedValues {
     pub baseline_shift: SpecifiedValue<BaselineShift>,
     pub clip_path: SpecifiedValue<ClipPath>,
     pub clip_rule: SpecifiedValue<ClipRule>,
-    pub comp_op: SpecifiedValue<CompOp>,
     pub color: SpecifiedValue<Color>,
     pub color_interpolation_filters: SpecifiedValue<ColorInterpolationFilters>,
     pub direction: SpecifiedValue<Direction>,
@@ -142,7 +141,6 @@ pub struct ComputedValues {
     pub baseline_shift: BaselineShift,
     pub clip_path: ClipPath,
     pub clip_rule: ClipRule,
-    pub comp_op: CompOp,
     pub color: Color,
     pub color_interpolation_filters: ColorInterpolationFilters,
     pub direction: Direction,
@@ -217,7 +215,6 @@ impl SpecifiedValues {
         compute_value!(self, computed, baseline_shift);
         compute_value!(self, computed, clip_path);
         compute_value!(self, computed, clip_rule);
-        compute_value!(self, computed, comp_op);
         compute_value!(self, computed, color);
         compute_value!(self, computed, color_interpolation_filters);
         compute_value!(self, computed, direction);
@@ -311,10 +308,6 @@ impl State {
                     self.values.color_interpolation_filters = parse_property(value, ())?;
                 }
 
-                Attribute::CompOp => {
-                    self.values.comp_op = parse_property(value, ())?;
-                }
-
                 Attribute::Direction => {
                     self.values.direction = parse_property(value, ())?;
                 }
@@ -737,40 +730,6 @@ make_property!(
     "sRGB" => Srgb,
 );
 
-// https://gitlab.gnome.org/GNOME/librsvg/issues/268 - can we remove this property?
-make_property!(
-    ComputedValues,
-    CompOp,
-    default: SrcOver,
-    inherits_automatically: false,
-
-    identifiers:
-    "clear" => Clear,
-    "src" => Src,
-    "dst" => Dst,
-    "src-over" => SrcOver,
-    "dst-over" => DstOver,
-    "src-in" => SrcIn,
-    "dst-in" => DstIn,
-    "src-out" => SrcOut,
-    "dst-out" => DstOut,
-    "src-atop" => SrcAtop,
-    "dst-atop" => DstAtop,
-    "xor" => Xor,
-    "plus" => Plus,
-    "multiply" => Multiply,
-    "screen" => Screen,
-    "overlay" => Overlay,
-    "darken" => Darken,
-    "lighten" => Lighten,
-    "color-dodge" => ColorDodge,
-    "color-burn" => ColorBurn,
-    "hard-light" => HardLight,
-    "soft-light" => SoftLight,
-    "difference" => Difference,
-    "exclusion" => Exclusion,
-);
-
 // https://www.w3.org/TR/SVG/text.html#DirectionProperty
 make_property!(
     ComputedValues,