Bug 1257180 - patch 2 - Directory can be sent via postMessage(), r=smaug

dom/base/StructuredCloneHolder.cpp

@@ -11,6 +11,7 @@
 #include "mozilla/dom/BlobBinding.h"
 #include "mozilla/dom/CryptoKey.h"
 #include "mozilla/dom/Directory.h"
+#include "mozilla/dom/DirectoryBinding.h"
 #include "mozilla/dom/File.h"
 #include "mozilla/dom/FileList.h"
 #include "mozilla/dom/FileListBinding.h"
@@ -658,7 +659,7 @@ ReadBlob(JSContext* aCx,
 
   MOZ_ASSERT(blobImpl);
 
-  // RefPtr<File> needs to go out of scope before toObjectOrNull() is
+  // RefPtr<File> needs to go out of scope before toObject() is
   // called because the static analysis thinks dereferencing XPCOM objects
   // can GC (because in some cases it can!), and a return statement with a
   // JSObject* type means that JSObject* is on the stack as a raw pointer
@@ -705,6 +706,80 @@ WriteBlob(JSStructuredCloneWriter* aWriter,
   return false;
 }
 
+// A directory is serialized as:
+// - pair of ints: SCTAG_DOM_DIRECTORY, 0
+// - pair of ints: type (eDOMRootDirectory/eDOMNotRootDirectory) - path length
+// - path as string
+bool
+WriteDirectory(JSStructuredCloneWriter* aWriter,
+               Directory* aDirectory)
+{
+  MOZ_ASSERT(aWriter);
+  MOZ_ASSERT(aDirectory);
+
+  nsAutoString path;
+  aDirectory->GetFullRealPath(path);
+
+  size_t charSize = sizeof(nsString::char_type);
+  return JS_WriteUint32Pair(aWriter, SCTAG_DOM_DIRECTORY, 0) &&
+         JS_WriteUint32Pair(aWriter, (uint32_t)aDirectory->Type(),
+                            path.Length()) &&
+         JS_WriteBytes(aWriter, path.get(), path.Length() * charSize);
+}
+
+JSObject*
+ReadDirectory(JSContext* aCx,
+              JSStructuredCloneReader* aReader,
+              uint32_t aZero,
+              StructuredCloneHolder* aHolder)
+{
+  MOZ_ASSERT(aCx);
+  MOZ_ASSERT(aReader);
+  MOZ_ASSERT(aHolder);
+  MOZ_ASSERT(aZero == 0);
+
+  uint32_t directoryType, lengthOfString;
+  if (!JS_ReadUint32Pair(aReader, &directoryType, &lengthOfString)) {
+    return nullptr;
+  }
+
+  MOZ_ASSERT(directoryType == Directory::eDOMRootDirectory ||
+             directoryType == Directory::eNotDOMRootDirectory);
+
+  nsAutoString path;
+  path.SetLength(lengthOfString);
+  size_t charSize = sizeof(nsString::char_type);
+  if (!JS_ReadBytes(aReader, (void*) path.BeginWriting(),
+                    lengthOfString * charSize)) {
+    return nullptr;
+  }
+
+  nsCOMPtr<nsIFile> file;
+  nsresult rv = NS_NewNativeLocalFile(NS_ConvertUTF16toUTF8(path), true,
+                                      getter_AddRefs(file));
+  if (NS_WARN_IF(NS_FAILED(rv))) {
+    return nullptr;
+  }
+
+  // RefPtr<Directory> needs to go out of scope before toObject() is
+  // called because the static analysis thinks dereferencing XPCOM objects
+  // can GC (because in some cases it can!), and a return statement with a
+  // JSObject* type means that JSObject* is on the stack as a raw pointer
+  // while destructors are running.
+  JS::Rooted<JS::Value> val(aCx);
+  {
+    RefPtr<Directory> directory =
+      Directory::Create(aHolder->ParentDuringRead(), file,
+                        (Directory::DirectoryType) directoryType);
+
+    if (!ToJSValue(aCx, directory, &val)) {
+      return nullptr;
+    }
+  }
+
+  return &val.toObject();
+}
+
 // Read the WriteFileList for the format.
 JSObject*
 ReadFileList(JSContext* aCx,
@@ -1002,6 +1077,10 @@ StructuredCloneHolder::CustomReadHandler(JSContext* aCx,
     return ReadBlob(aCx, aIndex, this);
   }
 
+  if (aTag == SCTAG_DOM_DIRECTORY) {
+    return ReadDirectory(aCx, aReader, aIndex, this);
+  }
+
   if (aTag == SCTAG_DOM_FILELIST) {
     return ReadFileList(aCx, aReader, aIndex, this);
   }
@@ -1042,6 +1121,14 @@ StructuredCloneHolder::CustomWriteHandler(JSContext* aCx,
     }
   }
 
+  // See if this is a Directory object.
+  {
+    Directory* directory = nullptr;
+    if (NS_SUCCEEDED(UNWRAP_OBJECT(Directory, aObj, directory))) {
+      return WriteDirectory(aWriter, directory);
+    }
+  }
+
   // See if this is a FileList object.
   {
     FileList* fileList = nullptr;

dom/base/StructuredCloneTags.h

@@ -17,7 +17,6 @@ namespace dom {
 enum StructuredCloneTags {
   SCTAG_BASE = JS_SCTAG_USER_MIN,
 
-  // These tags are used only for main thread structured clone.
   SCTAG_DOM_BLOB,
 
   // This tag is obsolete and exists only for backwards compatibility with
@@ -53,6 +52,8 @@ enum StructuredCloneTags {
 
   SCTAG_DOM_EXPANDED_PRINCIPAL,
 
+  SCTAG_DOM_DIRECTORY,
+
   SCTAG_DOM_MAX
 };
 

dom/base/test/test_postMessages.html

@@ -114,6 +114,34 @@ function create_fileList_forDir() {
   script.sendAsyncMessage("dir.open");
 }
 
+function create_directory() {
+  if (navigator.userAgent.toLowerCase().indexOf('Android') != -1) {
+    next();
+    return;
+  }
+
+  var url = SimpleTest.getTestFileURL("script_postmessages_fileList.js");
+  var script = SpecialPowers.loadChromeScript(url);
+
+  function onOpened(message) {
+    var fileList = document.getElementById('fileList');
+    SpecialPowers.wrap(fileList).mozSetDirectory(message.dir);
+
+    fileList.getFilesAndDirectories().then(function(list) {
+      // Just a simple test
+      is(list.length, 1, "This list has 1 element");
+      ok(list[0] instanceof Directory, "We have a directory.");
+
+      clonableObjects.push(list[0]);
+      script.destroy();
+      next();
+    });
+  }
+
+  script.addMessageListener("dir.opened", onOpened);
+  script.sendAsyncMessage("dir.open");
+}
+
 function runTests(obj) {
   ok(('clonableObjects' in obj) &&
      ('transferableObjects' in obj) &&
@@ -522,6 +550,7 @@ function test_messagePort_inWorkers() {
 var tests = [
   create_fileList_forFile,
   create_fileList_forDir,
+  create_directory,
 
   test_windowToWindow,
   test_windowToIframe,

dom/filesystem/GetDirectoryListingTask.cpp

@@ -72,7 +72,6 @@ GetDirectoryListingTaskChild::GetDirectoryListingTaskChild(FileSystemBase* aFile
 
 GetDirectoryListingTaskChild::~GetDirectoryListingTaskChild()
 {
-  MOZ_ASSERT(NS_IsMainThread());
   mFileSystem->AssertIsOnOwningThread();
 }
 

dom/filesystem/OSFileSystem.cpp

@@ -59,7 +59,6 @@ nsISupports*
 OSFileSystem::GetParentObject() const
 {
   AssertIsOnOwningThread();
-  MOZ_ASSERT(NS_IsMainThread(), "Only call on main thread!");
   return mParent;
 }
 
@@ -94,8 +93,6 @@ void
 OSFileSystem::Unlink()
 {
   AssertIsOnOwningThread();
-  MOZ_ASSERT(NS_IsMainThread(), "Only call on main thread!");
-
   mParent = nullptr;
 }
 
@@ -103,7 +100,6 @@ void
 OSFileSystem::Traverse(nsCycleCollectionTraversalCallback &cb)
 {
   AssertIsOnOwningThread();
-  MOZ_ASSERT(NS_IsMainThread(), "Only call on main thread!");
 
   OSFileSystem* tmp = this;
   NS_IMPL_CYCLE_COLLECTION_TRAVERSE(mParent);

dom/html/HTMLInputElement.cpp

@@ -5042,13 +5042,6 @@ HTMLInputElement::GetFilesAndDirectories(ErrorResult& aRv)
 
   for (uint32_t i = 0; i < filesAndDirs.Length(); ++i) {
     if (filesAndDirs[i].IsDirectory()) {
-#if defined(ANDROID) || defined(MOZ_B2G)
-      MOZ_ASSERT(false,
-                 "Directory picking should have been redirected to normal "
-                 "file picking for platforms that don't have a directory "
-                 "picker");
-#endif
-
       RefPtr<Directory> directory = filesAndDirs[i].GetAsDirectory();
 
       // In future we could refactor SetFilePickerFiltersFromAccept to return a