servo: Merge #17285 - geckolib: Don't panic when attempting to restyle an element with newly applied XBL bindings (from heycam:newly-bound); r=bholley

From https://bugzilla.mozilla.org/show_bug.cgi?id=1370793.

Source-Repo: https://github.com/servo/servo
Source-Revision: 8449eb4a6230d07faafc28a0d277b323e2da5e12

--HG--
extra : subtree_source : https%3A//hg.mozilla.org/projects/converted-servo-linear
extra : subtree_revision : 0a492da9c92ce20694f87777f42e31c622f4d596

servo/components/style/gecko/generated/bindings.rs

@@ -2113,9 +2113,9 @@ extern "C" {
 }
 extern "C" {
     pub fn Servo_StyleRule_GetSelectorTextAtIndex(rule:
-                                                        RawServoStyleRuleBorrowed,
-                                                    index: u32,
-                                                    result: *mut nsAString);
+                                                      RawServoStyleRuleBorrowed,
+                                                  index: u32,
+                                                  result: *mut nsAString);
 }
 extern "C" {
     pub fn Servo_StyleRule_GetSpecificityAtIndex(rule:

servo/components/style/gecko/generated/structs_debug.rs

@@ -6644,9 +6644,10 @@ pub mod root {
         #[derive(Debug, Copy, Clone, PartialEq, Eq, Hash)]
         pub enum TraversalRestyleBehavior {
             Normal = 0,
-            ForReconstruct = 1,
-            ForAnimationOnly = 2,
-            ForCSSRuleChanges = 3,
+            ForNewlyBoundElement = 1,
+            ForReconstruct = 2,
+            ForAnimationOnly = 3,
+            ForCSSRuleChanges = 4,
         }
         #[repr(i32)]
         #[derive(Debug, Copy, Clone, PartialEq, Eq, Hash)]
@@ -10436,6 +10437,12 @@ pub mod root {
             eFloatID_SpellCheckerUnderlineRelativeSize = 1,
             eFloatID_CaretAspectRatio = 2,
         }
+        pub const LookAndFeel_FontID_FontID_MINIMUM:
+                  root::mozilla::LookAndFeel_FontID =
+            LookAndFeel_FontID::eFont_Caption;
+        pub const LookAndFeel_FontID_FontID_MAXIMUM:
+                  root::mozilla::LookAndFeel_FontID =
+            LookAndFeel_FontID::eFont_Widget;
         #[repr(u32)]
         #[derive(Debug, Copy, Clone, PartialEq, Eq, Hash)]
         pub enum LookAndFeel_FontID {
@@ -34397,7 +34404,7 @@ pub mod root {
                    root::nsCharTraits ) ));
     }
     #[test]
-    fn __bindgen_test_layout__bindgen_ty_id_215166_instantiation_103() {
+    fn __bindgen_test_layout__bindgen_ty_id_215184_instantiation_103() {
         assert_eq!(::std::mem::size_of::<u8>() , 1usize , concat ! (
                    "Size of template specialization: " , stringify ! ( u8 )
                    ));
@@ -34406,7 +34413,7 @@ pub mod root {
                    ) ));
     }
     #[test]
-    fn __bindgen_test_layout__bindgen_ty_id_215202_instantiation_104() {
+    fn __bindgen_test_layout__bindgen_ty_id_215220_instantiation_104() {
         assert_eq!(::std::mem::size_of::<u8>() , 1usize , concat ! (
                    "Size of template specialization: " , stringify ! ( u8 )
                    ));

servo/components/style/gecko/generated/structs_release.rs

@@ -6500,9 +6500,10 @@ pub mod root {
         #[derive(Debug, Copy, Clone, PartialEq, Eq, Hash)]
         pub enum TraversalRestyleBehavior {
             Normal = 0,
-            ForReconstruct = 1,
-            ForAnimationOnly = 2,
-            ForCSSRuleChanges = 3,
+            ForNewlyBoundElement = 1,
+            ForReconstruct = 2,
+            ForAnimationOnly = 3,
+            ForCSSRuleChanges = 4,
         }
         #[repr(i32)]
         #[derive(Debug, Copy, Clone, PartialEq, Eq, Hash)]
@@ -10169,6 +10170,12 @@ pub mod root {
             eFloatID_SpellCheckerUnderlineRelativeSize = 1,
             eFloatID_CaretAspectRatio = 2,
         }
+        pub const LookAndFeel_FontID_FontID_MINIMUM:
+                  root::mozilla::LookAndFeel_FontID =
+            LookAndFeel_FontID::eFont_Caption;
+        pub const LookAndFeel_FontID_FontID_MAXIMUM:
+                  root::mozilla::LookAndFeel_FontID =
+            LookAndFeel_FontID::eFont_Widget;
         #[repr(u32)]
         #[derive(Debug, Copy, Clone, PartialEq, Eq, Hash)]
         pub enum LookAndFeel_FontID {
@@ -33852,7 +33859,7 @@ pub mod root {
                    root::nsCharTraits ) ));
     }
     #[test]
-    fn __bindgen_test_layout__bindgen_ty_id_211327_instantiation_98() {
+    fn __bindgen_test_layout__bindgen_ty_id_211345_instantiation_98() {
         assert_eq!(::std::mem::size_of::<u8>() , 1usize , concat ! (
                    "Size of template specialization: " , stringify ! ( u8 )
                    ));
@@ -33861,7 +33868,7 @@ pub mod root {
                    ) ));
     }
     #[test]
-    fn __bindgen_test_layout__bindgen_ty_id_211363_instantiation_99() {
+    fn __bindgen_test_layout__bindgen_ty_id_211381_instantiation_99() {
         assert_eq!(::std::mem::size_of::<u8>() , 1usize , concat ! (
                    "Size of template specialization: " , stringify ! ( u8 )
                    ));

servo/ports/geckolib/glue.rs

@@ -263,9 +263,11 @@ pub extern "C" fn Servo_TraverseSubtree(root: RawGeckoElementBorrowed,
 
     let traversal_flags = match (root_behavior, restyle_behavior) {
         (Root::Normal, Restyle::Normal) |
+        (Root::Normal, Restyle::ForNewlyBoundElement) |
         (Root::Normal, Restyle::ForAnimationOnly)
             => TraversalFlags::empty(),
         (Root::UnstyledChildrenOnly, Restyle::Normal) |
+        (Root::UnstyledChildrenOnly, Restyle::ForNewlyBoundElement) |
         (Root::UnstyledChildrenOnly, Restyle::ForAnimationOnly)
             => UNSTYLED_CHILDREN_ONLY,
         (Root::Normal, Restyle::ForCSSRuleChanges) => FOR_CSS_RULE_CHANGES,
@@ -291,6 +293,14 @@ pub extern "C" fn Servo_TraverseSubtree(root: RawGeckoElementBorrowed,
                      traversal_flags,
                      unsafe { &*snapshots });
 
+    if restyle_behavior == Restyle::ForNewlyBoundElement {
+        // In this mode, we only ever restyle new elements, so there is no
+        // need for a post-traversal, and the borrow_data().unwrap() call below
+        // could panic, so we don't bother computing whether a post-traversal
+        // is required.
+        return false;
+    }
+
     element.has_dirty_descendants() || element.borrow_data().unwrap().has_restyle()
 }