Auto merge of #12669 - splav:inline_pseudo_elements_layout#12367, r=notriddle

Inline pseudo elements layout#12367

<!-- Please describe your changes on the following line: -->
This PR fixes ignored paddings and margins for inline pseudo elements.

---
<!-- Thank you for contributing to Servo! Please replace each `[ ]` by `[X]` when the step is complete, and replace `__` with appropriate data: -->
- [X] `./mach build -d` does not report any errors
- [X] `./mach test-tidy` does not report any errors
- [X] These changes fix #12367 (github issue number if applicable).

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- [X] There are tests for these changes OR
- [ ] These changes do not require tests because _____

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components/layout/construct.rs

@@ -714,7 +714,11 @@ impl<'a, ConcreteThreadSafeLayoutNode: ThreadSafeLayoutNode>
         }
 
         let mut style = (*style).clone();
-        properties::modify_style_for_text(&mut style);
+        match node.get_pseudo_element_type() {
+            PseudoElementType::Before(_) |
+            PseudoElementType::After(_) => {}
+            _ => properties::modify_style_for_text(&mut style)
+        }
 
         let selected_style = node.selected_style(self.style_context());
 
@@ -950,7 +954,11 @@ impl<'a, ConcreteThreadSafeLayoutNode: ThreadSafeLayoutNode>
         // Modify the style as necessary. (See the comment in
         // `properties::modify_style_for_replaced_content()`.)
         let mut style = node.style(self.style_context()).clone();
-        properties::modify_style_for_replaced_content(&mut style);
+        match node.get_pseudo_element_type() {
+            PseudoElementType::Before(_) |
+            PseudoElementType::After(_) => {}
+            _ => properties::modify_style_for_replaced_content(&mut style)
+        }
 
         // If this is generated content, then we need to initialize the accumulator with the
         // fragment corresponding to that content. Otherwise, just initialize with the ordinary

components/layout/inline.rs

@@ -358,6 +358,10 @@ impl LineBreaker {
             let need_to_merge = match (&mut result.specific, &candidate.specific) {
                 (&mut SpecificFragmentInfo::ScannedText(ref mut result_info),
                  &SpecificFragmentInfo::ScannedText(ref candidate_info)) => {
+                    result.margin.inline_end == Au(0) &&
+                    candidate.margin.inline_start == Au(0) &&
+                    result.border_padding.inline_end == Au(0) &&
+                    candidate.border_padding.inline_start == Au(0) &&
                     result_info.selected() == candidate_info.selected() &&
                     arc_ptr_eq(&result_info.run, &candidate_info.run) &&
                         inline_contexts_are_equal(&result.inline_context,