auto merge of #4952 : bjwbell/servo/borders-txt-nodes, r=pcwalton

Inline fragments that are part of a text run don't have interior borders.
So don't draw interior borders or include them when calculating positioning.

Fixes https://github.com/servo/servo/issues/4658, where multiple text nodes that are adjacent have distinct borders.

r? @Ms2ger, @pcwalton

components/layout/construct.rs

@@ -195,14 +195,17 @@ impl InlineFragmentsAccumulator {
             mut fragments,
             enclosing_style
         } = self;
+        if let Some(enclosing_style) = enclosing_style {
+            let frag_len = fragments.len();
+            for (idx, frag) in fragments.iter_mut().enumerate() {
 
-        match enclosing_style {
-            Some(enclosing_style) => {
-                for frag in fragments.iter_mut() {
-                    frag.add_inline_context_style(enclosing_style.clone());
-                }
+                // frag is first inline fragment in the inline node
+                let is_first = idx == 0;
+                // frag is the last inline fragment in the inline node
+                let is_last = idx == frag_len - 1;
+
+                frag.add_inline_context_style(enclosing_style.clone(), is_first, is_last);
             }
-            None => {}
         }
         fragments
     }

components/layout/fragment.rs

@@ -23,6 +23,7 @@ use text;
 use util::OpaqueNodeMethods;
 use wrapper::{TLayoutNode, ThreadSafeLayoutNode};
 
+use geom::num::Zero;
 use geom::{Point2D, Rect, Size2D};
 use gfx::display_list::{BOX_SHADOW_INFLATION_FACTOR, OpaqueNode};
 use gfx::text::glyph::CharIndex;
@@ -46,7 +47,7 @@ use std::str::FromStr;
 use std::sync::{Arc, Mutex};
 use std::sync::mpsc::Sender;
 use string_cache::Atom;
-use style::properties::{ComputedValues, cascade_anonymous};
+use style::properties::{ComputedValues, cascade_anonymous, make_border};
 use style::node::{TElement, TNode};
 use style::values::computed::{LengthOrPercentage, LengthOrPercentageOrAuto, LengthOrPercentageOrNone};
 use style::computed_values::{clear, mix_blend_mode, overflow_wrap};
@@ -877,11 +878,31 @@ impl Fragment {
 
     /// Adds a style to the inline context for this fragment. If the inline
     /// context doesn't exist yet, it will be created.
-    pub fn add_inline_context_style(&mut self, style: Arc<ComputedValues>) {
+    pub fn add_inline_context_style(&mut self,
+                                    style: Arc<ComputedValues>,
+                                    first_frag: bool,
+                                    last_frag: bool) {
+
         if self.inline_context.is_none() {
             self.inline_context = Some(InlineFragmentContext::new());
         }
-        self.inline_context.as_mut().unwrap().styles.push(style.clone());
+        let frag_style = if first_frag && last_frag {
+            style.clone()
+        } else {
+            // Set the border width to zero and the border style to none on
+            // border sides that are not the outermost for a node container.
+            // Because with multiple inline fragments they don't have interior
+            // borders separating each other.
+            let mut border_width = style.logical_border_width();
+            if !last_frag {
+                border_width.set_right(style.writing_mode, Zero::zero());
+            }
+            if !first_frag {
+                border_width.set_left(style.writing_mode, Zero::zero());
+            }
+            Arc::new(make_border(&*style, border_width))
+        };
+        self.inline_context.as_mut().unwrap().styles.push(frag_style);
     }
 
     /// Determines which quantities (border/padding/margin/specified) should be included in the

components/style/properties.mako.rs

@@ -17,6 +17,7 @@ use util::geometry::Au;
 use url::Url;
 use cssparser::{Parser, Color, RGBA, AtRuleParser, DeclarationParser,
                 DeclarationListParser, parse_important, ToCss};
+use geom::num::Zero;
 use geom::SideOffsets2D;
 
 use values::specified::BorderStyle;
@@ -3534,6 +3535,21 @@ pub fn make_inline(style: &ComputedValues) -> ComputedValues {
     style
 }
 
+/// Sets `border_${side}_width` to the passed in values.
+/// If `border_${side}_width` == 0 also sets `border_${side}_style` = none.
+#[inline]
+pub fn make_border(style: &ComputedValues, border_width: LogicalMargin<Au>) -> ComputedValues {
+    let mut style = (*style).clone();
+    let physical_border = LogicalMargin::to_physical(&border_width, style.writing_mode);
+    % for side in ["top", "right", "bottom", "left"]:
+        style.border.make_unique().border_${side}_width = physical_border.${side};
+        if physical_border.${side} == Zero::zero() {
+            style.border.make_unique().border_${side}_style = BorderStyle::none;
+        }
+    % endfor
+    style
+}
+
 pub fn is_supported_property(property: &str) -> bool {
     match property {
         % for property in SHORTHANDS + LONGHANDS:

tests/ref/basic.list

@@ -31,6 +31,7 @@
 == img_dynamic_remove.html img_dynamic_remove_ref.html
 == upper_id_attr.html upper_id_attr_ref.html
 # inline_border_a.html inline_border_b.html
+== border_code_tag.html border_code_tag_ref.html
 == anon_block_inherit_a.html anon_block_inherit_b.html
 == attr_exists_selector.html attr_exists_selector_ref.html
 == attr_selector_case_sensitivity.html attr_selector_case_sensitivity_ref.html

tests/ref/border_code_tag.html

@@ -0,0 +1,12 @@
+<html>
+<head>
+<style>
+code {
+border: 2px solid #ccc;
+}
+</style>
+</head>
+<body>
+<code>Quotes: &quot;&quot;.</code>
+</body>
+</html>

tests/ref/border_code_tag_ref.html

@@ -0,0 +1,12 @@
+<html>
+<head>
+<style>
+code {
+border: 2px solid #ccc;
+}
+</style>
+</head>
+<body>
+<code>Quotes: "".</code>
+</body>
+</html>