From 37e9a4f2a27060703b670af330f6a0a2569294b6 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Emilio=20Cobos=20=C3=81lvarez?= <emilio@crisal.io>
Date: Fri, 16 Feb 2018 11:34:12 +0100
Subject: [PATCH] Bug 1436059: Fix inspector. r=xidorn

This removes a hack, but adds slightly more complex code in inspector-only code.

I'm not excited about this code, but this fixes ServoStyleRuleMap for XBL.

MozReview-Commit-ID: 6h0dCsiIWKU
---
 layout/style/ServoBindingList.h |  2 ++
 layout/style/ServoStyleSet.cpp  | 42 ++++++++++++++++++++++++++-------
 layout/style/StyleSheet.cpp     | 17 -------------
 layout/style/StyleSheet.h       | 19 +++++++++++----
 4 files changed, 50 insertions(+), 30 deletions(-)

diff --git a/layout/style/ServoBindingList.h b/layout/style/ServoBindingList.h
index f41fb632d7d1..03c891558ad9 100644
--- a/layout/style/ServoBindingList.h
+++ b/layout/style/ServoBindingList.h
@@ -183,6 +183,8 @@ SERVO_BINDING_FUNC(Servo_AuthorStyles_Create, RawServoAuthorStyles*)
 SERVO_BINDING_FUNC(Servo_AuthorStyles_AppendStyleSheet, void,
                    RawServoAuthorStylesBorrowedMut self,
                    const mozilla::ServoStyleSheet* gecko_sheet)
+SERVO_BINDING_FUNC(Servo_AuthorStyles_ForceDirty, void,
+                   RawServoAuthorStylesBorrowedMut self)
 // TODO(emilio): This will need to take an element to implement invalidation for
 // Shadow DOM.
 SERVO_BINDING_FUNC(Servo_AuthorStyles_Flush, void,
diff --git a/layout/style/ServoStyleSet.cpp b/layout/style/ServoStyleSet.cpp
index f11253bd686a..2937a90d7497 100644
--- a/layout/style/ServoStyleSet.cpp
+++ b/layout/style/ServoStyleSet.cpp
@@ -1270,23 +1270,41 @@ ServoStyleSet::ComputeAnimationValue(
 bool
 ServoStyleSet::EnsureUniqueInnerOnCSSSheets()
 {
-  AutoTArray<StyleSheet*, 32> queue;
+  using SheetOwner = Variant<ServoStyleSet*, nsXBLPrototypeBinding*>;
+
+  AutoTArray<Pair<StyleSheet*, SheetOwner>, 32> queue;
   for (auto& entryArray : mSheets) {
     for (auto& sheet : entryArray) {
-      queue.AppendElement(sheet);
+      StyleSheet* downcasted = sheet;
+      queue.AppendElement(MakePair(downcasted, SheetOwner { this }));
     }
   }
-  // This is a stub until more of the functionality of nsStyleSet is
-  // replicated for Servo here.
 
-  // Bug 1290276 will replicate the nsStyleSet work of checking
-  // a nsBindingManager
+  mDocument->BindingManager()->EnumerateBoundContentBindings(
+      [&](nsXBLBinding* aBinding) {
+        AutoTArray<StyleSheet*, 3> sheets;
+        aBinding->PrototypeBinding()->AppendStyleSheetsTo(sheets);
+        for (auto* sheet : sheets) {
+          queue.AppendElement(MakePair(sheet, SheetOwner { aBinding->PrototypeBinding() }));
+        }
+        return true;
+      });
 
+  bool anyXBLSheetChanged = false;
   while (!queue.IsEmpty()) {
     uint32_t idx = queue.Length() - 1;
-    StyleSheet* sheet = queue[idx];
+    auto* sheet = queue[idx].first();
+    SheetOwner owner = queue[idx].second();
     queue.RemoveElementAt(idx);
 
+    if (!sheet->HasUniqueInner() && owner.is<nsXBLPrototypeBinding*>()) {
+      if (auto* styles = owner.as<nsXBLPrototypeBinding*>()->GetServoStyles()) {
+        Servo_AuthorStyles_ForceDirty(styles);
+        mNeedsRestyleAfterEnsureUniqueInner = true;
+        anyXBLSheetChanged = true;
+      }
+    }
+
     // Only call EnsureUniqueInner for complete sheets. If we do call it on
     // incomplete sheets, we'll cause problems when the sheet is actually
     // loaded. We don't care about incomplete sheets here anyway, because this
@@ -1298,7 +1316,15 @@ ServoStyleSet::EnsureUniqueInnerOnCSSSheets()
     }
 
     // Enqueue all the sheet's children.
-    sheet->AppendAllChildSheets(queue);
+    AutoTArray<StyleSheet*, 3> children;
+    sheet->AppendAllChildSheets(children);
+    for (auto* sheet : children) {
+      queue.AppendElement(MakePair(sheet, owner));
+    }
+  }
+
+  if (anyXBLSheetChanged) {
+    SetStylistXBLStyleSheetsDirty();
   }
 
   if (mNeedsRestyleAfterEnsureUniqueInner) {
diff --git a/layout/style/StyleSheet.cpp b/layout/style/StyleSheet.cpp
index 07c8011b7110..89ef8cae1a01 100644
--- a/layout/style/StyleSheet.cpp
+++ b/layout/style/StyleSheet.cpp
@@ -401,23 +401,6 @@ StyleSheet::EnsureUniqueInner()
     return;
   }
 
-  // If this stylesheet is for XBL with Servo, don't bother cloning
-  // it, as it may break ServoStyleRuleMap. XBL stylesheets are not
-  // supposed to change anyway.
-  //
-  // The mDocument check is used as a fast reject path because no
-  // XBL stylesheets would have associated document, but in normal
-  // cases, content stylesheets should usually have one.
-  //
-  // FIXME(emilio): Shadow DOM definitely modifies stylesheets! Right now all of
-  // them are unique anyway because we don't support <link>, but that needs to
-  // change.
-  if (!mDocument && IsServo() &&
-      mStyleSets.Length() == 1 &&
-      mStyleSets[0]->AsServo()->IsForXBL()) {
-    return;
-  }
-
   StyleSheetInfo* clone = mInner->CloneFor(this);
   MOZ_ASSERT(clone);
   mInner->RemoveSheet(this);
diff --git a/layout/style/StyleSheet.h b/layout/style/StyleSheet.h
index 5e517a19e03b..b21f667eaaed 100644
--- a/layout/style/StyleSheet.h
+++ b/layout/style/StyleSheet.h
@@ -132,11 +132,20 @@ public:
                                              nsIDocument* aCloneDocument,
                                              nsINode* aCloneOwningNode) const = 0;
 
-  bool HasForcedUniqueInner() const { return mDirtyFlags &
-                                             FORCED_UNIQUE_INNER; }
-  bool HasModifiedRules() const { return mDirtyFlags &
-                                         MODIFIED_RULES; }
-  void ClearModifiedRules() { mDirtyFlags &= ~MODIFIED_RULES; }
+  bool HasForcedUniqueInner() const
+  {
+    return mDirtyFlags & FORCED_UNIQUE_INNER;
+  }
+
+  bool HasModifiedRules() const
+  {
+    return mDirtyFlags & MODIFIED_RULES;
+  }
+
+  void ClearModifiedRules()
+  {
+    mDirtyFlags &= ~MODIFIED_RULES;
+  }
 
   inline bool HasUniqueInner() const;
   void EnsureUniqueInner();