From 3faf40c8972c3e3674f38adfc5ce39fa2c1be865 Mon Sep 17 00:00:00 2001
From: Olli Pettay <Olli.Pettay@helsinki.fi>
Date: Sun, 4 Mar 2018 19:41:13 +0900
Subject: [PATCH] Bug 1425864 - Ensure printing documents which have ShadowDOM
 works, r=mrbkap,emilio

---
 dom/base/ShadowRoot.cpp  | 18 ++++++++++++++++
 dom/base/ShadowRoot.h    |  4 ++++
 dom/base/nsNodeUtils.cpp | 44 ++++++++++++++++++++++++++++++++--------
 3 files changed, 58 insertions(+), 8 deletions(-)

diff --git a/dom/base/ShadowRoot.cpp b/dom/base/ShadowRoot.cpp
index 639b5e130597..72a7a2bf928e 100644
--- a/dom/base/ShadowRoot.cpp
+++ b/dom/base/ShadowRoot.cpp
@@ -94,6 +94,24 @@ ShadowRoot::WrapObject(JSContext* aCx, JS::Handle<JSObject*> aGivenProto)
   return mozilla::dom::ShadowRootBinding::Wrap(aCx, this, aGivenProto);
 }
 
+void
+ShadowRoot::CloneInternalDataFrom(ShadowRoot* aOther)
+{
+  size_t sheetCount = aOther->SheetCount();
+  for (size_t i = 0; i < sheetCount; ++i) {
+    StyleSheet* sheet = aOther->SheetAt(i);
+    if (sheet->IsApplicable()) {
+      RefPtr<StyleSheet> clonedSheet =
+        sheet->Clone(nullptr, nullptr, nullptr, nullptr);
+      if (clonedSheet) {
+        AppendStyleSheet(*clonedSheet.get());
+        Servo_AuthorStyles_AppendStyleSheet(mServoStyles.get(),
+                                            clonedSheet->AsServo());
+      }
+    }
+  }
+}
+
 void
 ShadowRoot::AddSlot(HTMLSlotElement* aSlot)
 {
diff --git a/dom/base/ShadowRoot.h b/dom/base/ShadowRoot.h
index 19473c65d9a5..7791e0b6570d 100644
--- a/dom/base/ShadowRoot.h
+++ b/dom/base/ShadowRoot.h
@@ -89,6 +89,10 @@ public:
     return &DocumentOrShadowRoot::EnsureDOMStyleSheets();
   }
 
+  /**
+   * Clones internal state, for example stylesheets, of aOther to 'this'.
+   */
+  void CloneInternalDataFrom(ShadowRoot* aOther);
 private:
 
   /**
diff --git a/dom/base/nsNodeUtils.cpp b/dom/base/nsNodeUtils.cpp
index 625a6b2e573c..3595d01c7ec9 100644
--- a/dom/base/nsNodeUtils.cpp
+++ b/dom/base/nsNodeUtils.cpp
@@ -657,14 +657,42 @@ nsNodeUtils::CloneAndAdopt(nsINode *aNode, bool aClone, bool aDeep,
     }
   }
 
-  if (aDeep && !aClone && aNode->IsElement()) {
-    if (ShadowRoot* shadowRoot = aNode->AsElement()->GetShadowRoot()) {
-      nsCOMPtr<nsINode> child =
-        CloneAndAdopt(shadowRoot, aClone, aDeep, nodeInfoManager,
-                      aReparentScope, aNodesWithProperties, clone,
-                      aError);
-      if (NS_WARN_IF(aError.Failed())) {
-        return nullptr;
+  if (aDeep && aNode->IsElement()) {
+    if (aClone) {
+      if (clone->OwnerDoc()->IsStaticDocument()) {
+        ShadowRoot* originalShadowRoot = aNode->AsElement()->GetShadowRoot();
+        if (originalShadowRoot) {
+          ShadowRootInit init;
+          init.mMode = originalShadowRoot->Mode();
+          RefPtr<ShadowRoot> newShadowRoot =
+            clone->AsElement()->AttachShadow(init, aError);
+          if (NS_WARN_IF(aError.Failed())) {
+            return nullptr;
+          }
+
+          newShadowRoot->CloneInternalDataFrom(originalShadowRoot);
+          for (nsIContent* origChild = originalShadowRoot->GetFirstChild();
+               origChild;
+               origChild = origChild->GetNextSibling()) {
+            nsCOMPtr<nsINode> child =
+              CloneAndAdopt(origChild, aClone, aDeep, nodeInfoManager,
+                            aReparentScope, aNodesWithProperties, newShadowRoot,
+                            aError);
+            if (NS_WARN_IF(aError.Failed())) {
+              return nullptr;
+            }
+          }
+        }
+      }
+    } else {
+      if (ShadowRoot* shadowRoot = aNode->AsElement()->GetShadowRoot()) {
+        nsCOMPtr<nsINode> child =
+          CloneAndAdopt(shadowRoot, aClone, aDeep, nodeInfoManager,
+                        aReparentScope, aNodesWithProperties, clone,
+                        aError);
+        if (NS_WARN_IF(aError.Failed())) {
+          return nullptr;
+        }
       }
     }
   }