Add m-esr52 at 52.6.0

1 files changed, 1005 insertions, 0 deletions

diff --git a/editor/composer/nsEditorSpellCheck.cpp b/editor/composer/nsEditorSpellCheck.cpp
new file mode 100644
index 000000000..7cae48c1f
--- /dev/null
+++ b/editor/composer/nsEditorSpellCheck.cpp
@@ -0,0 +1,1005 @@
+/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
+/* vim: set ts=2 sts=2 sw=2 tw=80: */
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+#include <stdlib.h>                     // for getenv
+
+#include "mozilla/Attributes.h"         // for final
+#include "mozilla/Preferences.h"        // for Preferences
+#include "mozilla/Services.h"           // for GetXULChromeRegistryService
+#include "mozilla/dom/Element.h"        // for Element
+#include "mozilla/dom/Selection.h"
+#include "mozilla/mozalloc.h"           // for operator delete, etc
+#include "nsAString.h"                  // for nsAString_internal::IsEmpty, etc
+#include "nsComponentManagerUtils.h"    // for do_CreateInstance
+#include "nsDebug.h"                    // for NS_ENSURE_TRUE, etc
+#include "nsDependentSubstring.h"       // for Substring
+#include "nsEditorSpellCheck.h"
+#include "nsError.h"                    // for NS_ERROR_NOT_INITIALIZED, etc
+#include "nsIChromeRegistry.h"          // for nsIXULChromeRegistry
+#include "nsIContent.h"                 // for nsIContent
+#include "nsIContentPrefService.h"      // for nsIContentPrefService, etc
+#include "nsIContentPrefService2.h"     // for nsIContentPrefService2, etc
+#include "nsIDOMDocument.h"             // for nsIDOMDocument
+#include "nsIDOMElement.h"              // for nsIDOMElement
+#include "nsIDocument.h"                // for nsIDocument
+#include "nsIEditor.h"                  // for nsIEditor
+#include "nsIHTMLEditor.h"              // for nsIHTMLEditor
+#include "nsILoadContext.h"
+#include "nsISelection.h"               // for nsISelection
+#include "nsISpellChecker.h"            // for nsISpellChecker, etc
+#include "nsISupportsBase.h"            // for nsISupports
+#include "nsISupportsUtils.h"           // for NS_ADDREF
+#include "nsITextServicesDocument.h"    // for nsITextServicesDocument
+#include "nsITextServicesFilter.h"      // for nsITextServicesFilter
+#include "nsIURI.h"                     // for nsIURI
+#include "nsVariant.h"                  // for nsIWritableVariant, etc
+#include "nsLiteralString.h"            // for NS_LITERAL_STRING, etc
+#include "nsMemory.h"                   // for nsMemory
+#include "nsRange.h"
+#include "nsReadableUtils.h"            // for ToNewUnicode, EmptyString, etc
+#include "nsServiceManagerUtils.h"      // for do_GetService
+#include "nsString.h"                   // for nsAutoString, nsString, etc
+#include "nsStringFwd.h"                // for nsAFlatString
+#include "nsStyleUtil.h"                // for nsStyleUtil
+#include "nsXULAppAPI.h"                // for XRE_GetProcessType
+#include "nsIPlaintextEditor.h"         // for editor flags
+
+using namespace mozilla;
+using namespace mozilla::dom;
+
+class UpdateDictionaryHolder {
+  private:
+    nsEditorSpellCheck* mSpellCheck;
+  public:
+    explicit UpdateDictionaryHolder(nsEditorSpellCheck* esc): mSpellCheck(esc) {
+      if (mSpellCheck) {
+        mSpellCheck->BeginUpdateDictionary();
+      }
+    }
+    ~UpdateDictionaryHolder() {
+      if (mSpellCheck) {
+        mSpellCheck->EndUpdateDictionary();
+      }
+    }
+};
+
+#define CPS_PREF_NAME NS_LITERAL_STRING("spellcheck.lang")
+
+/**
+ * Gets the URI of aEditor's document.
+ */
+static nsresult
+GetDocumentURI(nsIEditor* aEditor, nsIURI * *aURI)
+{
+  NS_ENSURE_ARG_POINTER(aEditor);
+  NS_ENSURE_ARG_POINTER(aURI);
+
+  nsCOMPtr<nsIDOMDocument> domDoc;
+  aEditor->GetDocument(getter_AddRefs(domDoc));
+  NS_ENSURE_TRUE(domDoc, NS_ERROR_FAILURE);
+
+  nsCOMPtr<nsIDocument> doc = do_QueryInterface(domDoc);
+  NS_ENSURE_TRUE(doc, NS_ERROR_FAILURE);
+
+  nsCOMPtr<nsIURI> docUri = doc->GetDocumentURI();
+  NS_ENSURE_TRUE(docUri, NS_ERROR_FAILURE);
+
+  *aURI = docUri;
+  NS_ADDREF(*aURI);
+  return NS_OK;
+}
+
+static already_AddRefed<nsILoadContext>
+GetLoadContext(nsIEditor* aEditor)
+{
+  nsCOMPtr<nsIDOMDocument> domDoc;
+  aEditor->GetDocument(getter_AddRefs(domDoc));
+  NS_ENSURE_TRUE(domDoc, nullptr);
+
+  nsCOMPtr<nsIDocument> doc = do_QueryInterface(domDoc);
+  NS_ENSURE_TRUE(doc, nullptr);
+
+  nsCOMPtr<nsILoadContext> loadContext = doc->GetLoadContext();
+  return loadContext.forget();
+}
+
+/**
+ * Fetches the dictionary stored in content prefs and maintains state during the
+ * fetch, which is asynchronous.
+ */
+class DictionaryFetcher final : public nsIContentPrefCallback2
+{
+public:
+  NS_DECL_ISUPPORTS
+
+  DictionaryFetcher(nsEditorSpellCheck* aSpellCheck,
+                    nsIEditorSpellCheckCallback* aCallback,
+                    uint32_t aGroup)
+    : mCallback(aCallback), mGroup(aGroup), mSpellCheck(aSpellCheck) {}
+
+  NS_IMETHOD Fetch(nsIEditor* aEditor);
+
+  NS_IMETHOD HandleResult(nsIContentPref* aPref) override
+  {
+    nsCOMPtr<nsIVariant> value;
+    nsresult rv = aPref->GetValue(getter_AddRefs(value));
+    NS_ENSURE_SUCCESS(rv, rv);
+    value->GetAsAString(mDictionary);
+    return NS_OK;
+  }
+
+  NS_IMETHOD HandleCompletion(uint16_t reason) override
+  {
+    mSpellCheck->DictionaryFetched(this);
+    return NS_OK;
+  }
+
+  NS_IMETHOD HandleError(nsresult error) override
+  {
+    return NS_OK;
+  }
+
+  nsCOMPtr<nsIEditorSpellCheckCallback> mCallback;
+  uint32_t mGroup;
+  nsString mRootContentLang;
+  nsString mRootDocContentLang;
+  nsString mDictionary;
+
+private:
+  ~DictionaryFetcher() {}
+
+  RefPtr<nsEditorSpellCheck> mSpellCheck;
+};
+NS_IMPL_ISUPPORTS(DictionaryFetcher, nsIContentPrefCallback2)
+
+NS_IMETHODIMP
+DictionaryFetcher::Fetch(nsIEditor* aEditor)
+{
+  NS_ENSURE_ARG_POINTER(aEditor);
+
+  nsresult rv;
+
+  nsCOMPtr<nsIURI> docUri;
+  rv = GetDocumentURI(aEditor, getter_AddRefs(docUri));
+  NS_ENSURE_SUCCESS(rv, rv);
+
+  nsAutoCString docUriSpec;
+  rv = docUri->GetSpec(docUriSpec);
+  NS_ENSURE_SUCCESS(rv, rv);
+
+  nsCOMPtr<nsIContentPrefService2> contentPrefService =
+    do_GetService(NS_CONTENT_PREF_SERVICE_CONTRACTID);
+  NS_ENSURE_TRUE(contentPrefService, NS_ERROR_NOT_AVAILABLE);
+
+  nsCOMPtr<nsILoadContext> loadContext = GetLoadContext(aEditor);
+  rv = contentPrefService->GetByDomainAndName(NS_ConvertUTF8toUTF16(docUriSpec),
+                                              CPS_PREF_NAME, loadContext,
+                                              this);
+  NS_ENSURE_SUCCESS(rv, rv);
+
+  return NS_OK;
+}
+
+/**
+ * Stores the current dictionary for aEditor's document URL.
+ */
+static nsresult
+StoreCurrentDictionary(nsIEditor* aEditor, const nsAString& aDictionary)
+{
+  NS_ENSURE_ARG_POINTER(aEditor);
+
+  nsresult rv;
+
+  nsCOMPtr<nsIURI> docUri;
+  rv = GetDocumentURI(aEditor, getter_AddRefs(docUri));
+  NS_ENSURE_SUCCESS(rv, rv);
+
+  nsAutoCString docUriSpec;
+  rv = docUri->GetSpec(docUriSpec);
+  NS_ENSURE_SUCCESS(rv, rv);
+
+  RefPtr<nsVariant> prefValue = new nsVariant();
+  prefValue->SetAsAString(aDictionary);
+
+  nsCOMPtr<nsIContentPrefService2> contentPrefService =
+    do_GetService(NS_CONTENT_PREF_SERVICE_CONTRACTID);
+  NS_ENSURE_TRUE(contentPrefService, NS_ERROR_NOT_INITIALIZED);
+
+  nsCOMPtr<nsILoadContext> loadContext = GetLoadContext(aEditor);
+  return contentPrefService->Set(NS_ConvertUTF8toUTF16(docUriSpec),
+                                 CPS_PREF_NAME, prefValue, loadContext,
+                                 nullptr);
+}
+
+/**
+ * Forgets the current dictionary stored for aEditor's document URL.
+ */
+static nsresult
+ClearCurrentDictionary(nsIEditor* aEditor)
+{
+  NS_ENSURE_ARG_POINTER(aEditor);
+
+  nsresult rv;
+
+  nsCOMPtr<nsIURI> docUri;
+  rv = GetDocumentURI(aEditor, getter_AddRefs(docUri));
+  NS_ENSURE_SUCCESS(rv, rv);
+
+  nsAutoCString docUriSpec;
+  rv = docUri->GetSpec(docUriSpec);
+  NS_ENSURE_SUCCESS(rv, rv);
+
+  nsCOMPtr<nsIContentPrefService2> contentPrefService =
+    do_GetService(NS_CONTENT_PREF_SERVICE_CONTRACTID);
+  NS_ENSURE_TRUE(contentPrefService, NS_ERROR_NOT_INITIALIZED);
+
+  nsCOMPtr<nsILoadContext> loadContext = GetLoadContext(aEditor);
+  return contentPrefService->RemoveByDomainAndName(
+    NS_ConvertUTF8toUTF16(docUriSpec), CPS_PREF_NAME, loadContext, nullptr);
+}
+
+NS_IMPL_CYCLE_COLLECTING_ADDREF(nsEditorSpellCheck)
+NS_IMPL_CYCLE_COLLECTING_RELEASE(nsEditorSpellCheck)
+
+NS_INTERFACE_MAP_BEGIN(nsEditorSpellCheck)
+  NS_INTERFACE_MAP_ENTRY(nsIEditorSpellCheck)
+  NS_INTERFACE_MAP_ENTRY_AMBIGUOUS(nsISupports, nsIEditorSpellCheck)
+  NS_INTERFACE_MAP_ENTRIES_CYCLE_COLLECTION(nsEditorSpellCheck)
+NS_INTERFACE_MAP_END
+
+NS_IMPL_CYCLE_COLLECTION(nsEditorSpellCheck,
+                         mEditor,
+                         mSpellChecker,
+                         mTxtSrvFilter)
+
+nsEditorSpellCheck::nsEditorSpellCheck()
+  : mSuggestedWordIndex(0)
+  , mDictionaryIndex(0)
+  , mEditor(nullptr)
+  , mDictionaryFetcherGroup(0)
+  , mUpdateDictionaryRunning(false)
+{
+}
+
+nsEditorSpellCheck::~nsEditorSpellCheck()
+{
+  // Make sure we blow the spellchecker away, just in
+  // case it hasn't been destroyed already.
+  mSpellChecker = nullptr;
+}
+
+// The problem is that if the spell checker does not exist, we can not tell
+// which dictionaries are installed. This function works around the problem,
+// allowing callers to ask if we can spell check without actually doing so (and
+// enabling or disabling UI as necessary). This just creates a spellcheck
+// object if needed and asks it for the dictionary list.
+NS_IMETHODIMP
+nsEditorSpellCheck::CanSpellCheck(bool* _retval)
+{
+  nsresult rv;
+  nsCOMPtr<nsISpellChecker> spellChecker;
+  if (! mSpellChecker) {
+    spellChecker = do_CreateInstance(NS_SPELLCHECKER_CONTRACTID, &rv);
+    NS_ENSURE_SUCCESS(rv, rv);
+  } else {
+    spellChecker = mSpellChecker;
+  }
+  nsTArray<nsString> dictList;
+  rv = spellChecker->GetDictionaryList(&dictList);
+  NS_ENSURE_SUCCESS(rv, rv);
+
+  *_retval = (dictList.Length() > 0);
+  return NS_OK;
+}
+
+// Instances of this class can be used as either runnables or RAII helpers.
+class CallbackCaller final : public Runnable
+{
+public:
+  explicit CallbackCaller(nsIEditorSpellCheckCallback* aCallback)
+    : mCallback(aCallback) {}
+
+  ~CallbackCaller()
+  {
+    Run();
+  }
+
+  NS_IMETHOD Run() override
+  {
+    if (mCallback) {
+      mCallback->EditorSpellCheckDone();
+      mCallback = nullptr;
+    }
+    return NS_OK;
+  }
+
+private:
+  nsCOMPtr<nsIEditorSpellCheckCallback> mCallback;
+};
+
+NS_IMETHODIMP
+nsEditorSpellCheck::InitSpellChecker(nsIEditor* aEditor, bool aEnableSelectionChecking, nsIEditorSpellCheckCallback* aCallback)
+{
+  NS_ENSURE_TRUE(aEditor, NS_ERROR_NULL_POINTER);
+  mEditor = aEditor;
+
+  nsresult rv;
+
+  // We can spell check with any editor type
+  nsCOMPtr<nsITextServicesDocument>tsDoc =
+     do_CreateInstance("@mozilla.org/textservices/textservicesdocument;1", &rv);
+  NS_ENSURE_SUCCESS(rv, rv);
+
+  NS_ENSURE_TRUE(tsDoc, NS_ERROR_NULL_POINTER);
+
+  tsDoc->SetFilter(mTxtSrvFilter);
+
+  // Pass the editor to the text services document
+  rv = tsDoc->InitWithEditor(aEditor);
+  NS_ENSURE_SUCCESS(rv, rv);
+
+  if (aEnableSelectionChecking) {
+    // Find out if the section is collapsed or not.
+    // If it isn't, we want to spellcheck just the selection.
+
+    nsCOMPtr<nsISelection> domSelection;
+    aEditor->GetSelection(getter_AddRefs(domSelection));
+    if (NS_WARN_IF(!domSelection)) {
+      return NS_ERROR_FAILURE;
+    }
+    RefPtr<Selection> selection = domSelection->AsSelection();
+
+    int32_t count = 0;
+
+    rv = selection->GetRangeCount(&count);
+    NS_ENSURE_SUCCESS(rv, rv);
+
+    if (count > 0) {
+      RefPtr<nsRange> range = selection->GetRangeAt(0);
+      NS_ENSURE_STATE(range);
+
+      bool collapsed = false;
+      rv = range->GetCollapsed(&collapsed);
+      NS_ENSURE_SUCCESS(rv, rv);
+
+      if (!collapsed) {
+        // We don't want to touch the range in the selection,
+        // so create a new copy of it.
+
+        RefPtr<nsRange> rangeBounds = range->CloneRange();
+
+        // Make sure the new range spans complete words.
+
+        rv = tsDoc->ExpandRangeToWordBoundaries(rangeBounds);
+        NS_ENSURE_SUCCESS(rv, rv);
+
+        // Now tell the text services that you only want
+        // to iterate over the text in this range.
+
+        rv = tsDoc->SetExtent(rangeBounds);
+        NS_ENSURE_SUCCESS(rv, rv);
+      }
+    }
+  }
+
+  mSpellChecker = do_CreateInstance(NS_SPELLCHECKER_CONTRACTID, &rv);
+  NS_ENSURE_SUCCESS(rv, rv);
+
+  NS_ENSURE_TRUE(mSpellChecker, NS_ERROR_NULL_POINTER);
+
+  rv = mSpellChecker->SetDocument(tsDoc, true);
+  NS_ENSURE_SUCCESS(rv, rv);
+
+  // do not fail if UpdateCurrentDictionary fails because this method may
+  // succeed later.
+  rv = UpdateCurrentDictionary(aCallback);
+  if (NS_FAILED(rv) && aCallback) {
+    // However, if it does fail, we still need to call the callback since we
+    // discard the failure.  Do it asynchronously so that the caller is always
+    // guaranteed async behavior.
+    RefPtr<CallbackCaller> caller = new CallbackCaller(aCallback);
+    NS_ENSURE_STATE(caller);
+    rv = NS_DispatchToMainThread(caller);
+    NS_ENSURE_SUCCESS(rv, rv);
+  }
+
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+nsEditorSpellCheck::GetNextMisspelledWord(char16_t **aNextMisspelledWord)
+{
+  NS_ENSURE_TRUE(mSpellChecker, NS_ERROR_NOT_INITIALIZED);
+
+  nsAutoString nextMisspelledWord;
+
+  DeleteSuggestedWordList();
+  // Beware! This may flush notifications via synchronous
+  // ScrollSelectionIntoView.
+  nsresult rv = mSpellChecker->NextMisspelledWord(nextMisspelledWord,
+                                                  &mSuggestedWordList);
+
+  *aNextMisspelledWord = ToNewUnicode(nextMisspelledWord);
+  return rv;
+}
+
+NS_IMETHODIMP
+nsEditorSpellCheck::GetSuggestedWord(char16_t **aSuggestedWord)
+{
+  nsAutoString word;
+  // XXX This is buggy if mSuggestedWordList.Length() is over INT32_MAX.
+  if (mSuggestedWordIndex < static_cast<int32_t>(mSuggestedWordList.Length())) {
+    *aSuggestedWord = ToNewUnicode(mSuggestedWordList[mSuggestedWordIndex]);
+    mSuggestedWordIndex++;
+  } else {
+    // A blank string signals that there are no more strings
+    *aSuggestedWord = ToNewUnicode(EmptyString());
+  }
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+nsEditorSpellCheck::CheckCurrentWord(const char16_t *aSuggestedWord,
+                                     bool *aIsMisspelled)
+{
+  NS_ENSURE_TRUE(mSpellChecker, NS_ERROR_NOT_INITIALIZED);
+
+  DeleteSuggestedWordList();
+  return mSpellChecker->CheckWord(nsDependentString(aSuggestedWord),
+                                  aIsMisspelled, &mSuggestedWordList);
+}
+
+NS_IMETHODIMP
+nsEditorSpellCheck::CheckCurrentWordNoSuggest(const char16_t *aSuggestedWord,
+                                              bool *aIsMisspelled)
+{
+  NS_ENSURE_TRUE(mSpellChecker, NS_ERROR_NOT_INITIALIZED);
+
+  return mSpellChecker->CheckWord(nsDependentString(aSuggestedWord),
+                                  aIsMisspelled, nullptr);
+}
+
+NS_IMETHODIMP
+nsEditorSpellCheck::ReplaceWord(const char16_t *aMisspelledWord,
+                                const char16_t *aReplaceWord,
+                                bool             allOccurrences)
+{
+  NS_ENSURE_TRUE(mSpellChecker, NS_ERROR_NOT_INITIALIZED);
+
+  return mSpellChecker->Replace(nsDependentString(aMisspelledWord),
+                                nsDependentString(aReplaceWord), allOccurrences);
+}
+
+NS_IMETHODIMP
+nsEditorSpellCheck::IgnoreWordAllOccurrences(const char16_t *aWord)
+{
+  NS_ENSURE_TRUE(mSpellChecker, NS_ERROR_NOT_INITIALIZED);
+
+  return mSpellChecker->IgnoreAll(nsDependentString(aWord));
+}
+
+NS_IMETHODIMP
+nsEditorSpellCheck::GetPersonalDictionary()
+{
+  NS_ENSURE_TRUE(mSpellChecker, NS_ERROR_NOT_INITIALIZED);
+
+   // We can spell check with any editor type
+  mDictionaryList.Clear();
+  mDictionaryIndex = 0;
+  return mSpellChecker->GetPersonalDictionary(&mDictionaryList);
+}
+
+NS_IMETHODIMP
+nsEditorSpellCheck::GetPersonalDictionaryWord(char16_t **aDictionaryWord)
+{
+  // XXX This is buggy if mDictionaryList.Length() is over INT32_MAX.
+  if (mDictionaryIndex < static_cast<int32_t>(mDictionaryList.Length())) {
+    *aDictionaryWord = ToNewUnicode(mDictionaryList[mDictionaryIndex]);
+    mDictionaryIndex++;
+  } else {
+    // A blank string signals that there are no more strings
+    *aDictionaryWord = ToNewUnicode(EmptyString());
+  }
+
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+nsEditorSpellCheck::AddWordToDictionary(const char16_t *aWord)
+{
+  NS_ENSURE_TRUE(mSpellChecker, NS_ERROR_NOT_INITIALIZED);
+
+  return mSpellChecker->AddWordToPersonalDictionary(nsDependentString(aWord));
+}
+
+NS_IMETHODIMP
+nsEditorSpellCheck::RemoveWordFromDictionary(const char16_t *aWord)
+{
+  NS_ENSURE_TRUE(mSpellChecker, NS_ERROR_NOT_INITIALIZED);
+
+  return mSpellChecker->RemoveWordFromPersonalDictionary(nsDependentString(aWord));
+}
+
+NS_IMETHODIMP
+nsEditorSpellCheck::GetDictionaryList(char16_t ***aDictionaryList, uint32_t *aCount)
+{
+  NS_ENSURE_TRUE(mSpellChecker, NS_ERROR_NOT_INITIALIZED);
+
+  NS_ENSURE_TRUE(aDictionaryList && aCount, NS_ERROR_NULL_POINTER);
+
+  *aDictionaryList = 0;
+  *aCount          = 0;
+
+  nsTArray<nsString> dictList;
+
+  nsresult rv = mSpellChecker->GetDictionaryList(&dictList);
+
+  NS_ENSURE_SUCCESS(rv, rv);
+
+  char16_t **tmpPtr = 0;
+
+  if (dictList.IsEmpty()) {
+    // If there are no dictionaries, return an array containing
+    // one element and a count of one.
+
+    tmpPtr = (char16_t **)moz_xmalloc(sizeof(char16_t *));
+
+    NS_ENSURE_TRUE(tmpPtr, NS_ERROR_OUT_OF_MEMORY);
+
+    *tmpPtr          = 0;
+    *aDictionaryList = tmpPtr;
+    *aCount          = 0;
+
+    return NS_OK;
+  }
+
+  tmpPtr = (char16_t **)moz_xmalloc(sizeof(char16_t *) * dictList.Length());
+
+  NS_ENSURE_TRUE(tmpPtr, NS_ERROR_OUT_OF_MEMORY);
+
+  *aDictionaryList = tmpPtr;
+  *aCount          = dictList.Length();
+
+  for (uint32_t i = 0; i < *aCount; i++) {
+    tmpPtr[i] = ToNewUnicode(dictList[i]);
+  }
+
+  return rv;
+}
+
+NS_IMETHODIMP
+nsEditorSpellCheck::GetCurrentDictionary(nsAString& aDictionary)
+{
+  NS_ENSURE_TRUE(mSpellChecker, NS_ERROR_NOT_INITIALIZED);
+
+  return mSpellChecker->GetCurrentDictionary(aDictionary);
+}
+
+NS_IMETHODIMP
+nsEditorSpellCheck::SetCurrentDictionary(const nsAString& aDictionary)
+{
+  NS_ENSURE_TRUE(mSpellChecker, NS_ERROR_NOT_INITIALIZED);
+
+  RefPtr<nsEditorSpellCheck> kungFuDeathGrip = this;
+
+  // The purpose of mUpdateDictionaryRunning is to avoid doing all of this if
+  // UpdateCurrentDictionary's helper method DictionaryFetched, which calls us,
+  // is on the stack. In other words: Only do this, if the user manually selected a
+  // dictionary to use.
+  if (!mUpdateDictionaryRunning) {
+
+    // Ignore pending dictionary fetchers by increasing this number.
+    mDictionaryFetcherGroup++;
+
+    uint32_t flags = 0;
+    mEditor->GetFlags(&flags);
+    if (!(flags & nsIPlaintextEditor::eEditorMailMask)) {
+      if (!aDictionary.IsEmpty() && (mPreferredLang.IsEmpty() ||
+          !mPreferredLang.Equals(aDictionary,
+                                 nsCaseInsensitiveStringComparator()))) {
+        // When user sets dictionary manually, we store this value associated
+        // with editor url, if it doesn't match the document language exactly.
+        // For example on "en" sites, we need to store "en-GB", otherwise
+        // the language might jump back to en-US although the user explicitly
+        // chose otherwise.
+        StoreCurrentDictionary(mEditor, aDictionary);
+#ifdef DEBUG_DICT
+        printf("***** Writing content preferences for |%s|\n",
+               NS_ConvertUTF16toUTF8(aDictionary).get());
+#endif
+      } else {
+        // If user sets a dictionary matching the language defined by
+        // document, we consider content pref has been canceled, and we clear it.
+        ClearCurrentDictionary(mEditor);
+#ifdef DEBUG_DICT
+        printf("***** Clearing content preferences for |%s|\n",
+               NS_ConvertUTF16toUTF8(aDictionary).get());
+#endif
+      }
+
+      // Also store it in as a preference, so we can use it as a fallback.
+      // We don't want this for mail composer because it uses
+      // "spellchecker.dictionary" as a preference.
+      Preferences::SetString("spellchecker.dictionary", aDictionary);
+#ifdef DEBUG_DICT
+      printf("***** Storing spellchecker.dictionary |%s|\n",
+             NS_ConvertUTF16toUTF8(aDictionary).get());
+#endif
+    }
+  }
+  return mSpellChecker->SetCurrentDictionary(aDictionary);
+}
+
+NS_IMETHODIMP
+nsEditorSpellCheck::UninitSpellChecker()
+{
+  NS_ENSURE_TRUE(mSpellChecker, NS_ERROR_NOT_INITIALIZED);
+
+  // Cleanup - kill the spell checker
+  DeleteSuggestedWordList();
+  mDictionaryList.Clear();
+  mDictionaryIndex = 0;
+  mSpellChecker = nullptr;
+  return NS_OK;
+}
+
+
+NS_IMETHODIMP
+nsEditorSpellCheck::SetFilter(nsITextServicesFilter *filter)
+{
+  mTxtSrvFilter = filter;
+  return NS_OK;
+}
+
+nsresult
+nsEditorSpellCheck::DeleteSuggestedWordList()
+{
+  mSuggestedWordList.Clear();
+  mSuggestedWordIndex = 0;
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+nsEditorSpellCheck::UpdateCurrentDictionary(nsIEditorSpellCheckCallback* aCallback)
+{
+  if (NS_WARN_IF(!mSpellChecker)) {
+    return NS_ERROR_NOT_INITIALIZED;
+  }
+
+  nsresult rv;
+
+  RefPtr<nsEditorSpellCheck> kungFuDeathGrip = this;
+
+  // Get language with html5 algorithm
+  nsCOMPtr<nsIContent> rootContent;
+  nsCOMPtr<nsIHTMLEditor> htmlEditor = do_QueryInterface(mEditor);
+  if (htmlEditor) {
+    rootContent = htmlEditor->GetActiveEditingHost();
+  } else {
+    nsCOMPtr<nsIDOMElement> rootElement;
+    rv = mEditor->GetRootElement(getter_AddRefs(rootElement));
+    NS_ENSURE_SUCCESS(rv, rv);
+    rootContent = do_QueryInterface(rootElement);
+  }
+
+  // Try to get topmost document's document element for embedded mail editor.
+  uint32_t flags = 0;
+  mEditor->GetFlags(&flags);
+  if (flags & nsIPlaintextEditor::eEditorMailMask) {
+    nsCOMPtr<nsIDocument> ownerDoc = rootContent->OwnerDoc();
+    NS_ENSURE_TRUE(ownerDoc, NS_ERROR_FAILURE);
+    nsIDocument* parentDoc = ownerDoc->GetParentDocument();
+    if (parentDoc) {
+      rootContent = do_QueryInterface(parentDoc->GetDocumentElement());
+    }
+  }
+
+  if (!rootContent) {
+    return NS_ERROR_FAILURE;
+  }
+
+  RefPtr<DictionaryFetcher> fetcher =
+    new DictionaryFetcher(this, aCallback, mDictionaryFetcherGroup);
+  rootContent->GetLang(fetcher->mRootContentLang);
+  nsCOMPtr<nsIDocument> doc = rootContent->GetUncomposedDoc();
+  NS_ENSURE_STATE(doc);
+  doc->GetContentLanguage(fetcher->mRootDocContentLang);
+
+  rv = fetcher->Fetch(mEditor);
+  NS_ENSURE_SUCCESS(rv, rv);
+
+  return NS_OK;
+}
+
+// Helper function that iterates over the list of dictionaries and sets the one
+// that matches based on a given comparison type.
+nsresult
+nsEditorSpellCheck::TryDictionary(const nsAString& aDictName,
+                                  nsTArray<nsString>& aDictList,
+                                  enum dictCompare aCompareType)
+{
+  nsresult rv = NS_ERROR_NOT_AVAILABLE;
+
+  for (uint32_t i = 0; i < aDictList.Length(); i++) {
+    nsAutoString dictStr(aDictList.ElementAt(i));
+    bool equals = false;
+    switch (aCompareType) {
+      case DICT_NORMAL_COMPARE:
+        equals = aDictName.Equals(dictStr);
+        break;
+      case DICT_COMPARE_CASE_INSENSITIVE:
+        equals = aDictName.Equals(dictStr, nsCaseInsensitiveStringComparator());
+        break;
+      case DICT_COMPARE_DASHMATCH:
+        equals = nsStyleUtil::DashMatchCompare(dictStr, aDictName, nsCaseInsensitiveStringComparator());
+        break;
+    }
+    if (equals) {
+      rv = mSpellChecker->SetCurrentDictionary(dictStr);
+#ifdef DEBUG_DICT
+      if (NS_SUCCEEDED(rv))
+        printf("***** Set |%s|.\n", NS_ConvertUTF16toUTF8(dictStr).get());
+#endif
+      // We always break here. We tried to set the dictionary to an existing
+      // dictionary from the list. This must work, if it doesn't, there is
+      // no point trying another one.
+      break;
+    }
+  }
+  return rv;
+}
+
+nsresult
+nsEditorSpellCheck::DictionaryFetched(DictionaryFetcher* aFetcher)
+{
+  MOZ_ASSERT(aFetcher);
+  RefPtr<nsEditorSpellCheck> kungFuDeathGrip = this;
+
+  // Important: declare the holder after the callback caller so that the former
+  // is destructed first so that it's not active when the callback is called.
+  CallbackCaller callbackCaller(aFetcher->mCallback);
+  UpdateDictionaryHolder holder(this);
+
+  if (aFetcher->mGroup < mDictionaryFetcherGroup) {
+    // SetCurrentDictionary was called after the fetch started.  Don't overwrite
+    // that dictionary with the fetched one.
+    return NS_OK;
+  }
+
+  /*
+   * We try to derive the dictionary to use based on the following priorities:
+   * 1) Content preference, so the language the user set for the site before.
+   *    (Introduced in bug 678842 and corrected in bug 717433.)
+   * 2) Language set by the website, or any other dictionary that partly
+   *    matches that. (Introduced in bug 338427.)
+   *    Eg. if the website is "en-GB", a user who only has "en-US" will get
+   *    that. If the website is generic "en", the user will get one of the
+   *    "en-*" installed, (almost) at random.
+   *    However, we prefer what is stored in "spellchecker.dictionary",
+   *    so if the user chose "en-AU" before, they will get "en-AU" on a plain
+   *    "en" site. (Introduced in bug 682564.)
+   * 3) The value of "spellchecker.dictionary" which reflects a previous
+   *    language choice of the user (on another site).
+   *    (This was the original behaviour before the aforementioned bugs
+   *    landed).
+   * 4) The user's locale.
+   * 5) Use the current dictionary that is currently set.
+   * 6) The content of the "LANG" environment variable (if set).
+   * 7) The first spell check dictionary installed.
+   */
+
+  // Get the language from the element or its closest parent according to:
+  // https://html.spec.whatwg.org/#attr-lang
+  // This is used in SetCurrentDictionary.
+  mPreferredLang.Assign(aFetcher->mRootContentLang);
+#ifdef DEBUG_DICT
+  printf("***** mPreferredLang (element) |%s|\n",
+         NS_ConvertUTF16toUTF8(mPreferredLang).get());
+#endif
+
+  // If no luck, try the "Content-Language" header.
+  if (mPreferredLang.IsEmpty()) {
+    mPreferredLang.Assign(aFetcher->mRootDocContentLang);
+#ifdef DEBUG_DICT
+    printf("***** mPreferredLang (content-language) |%s|\n",
+           NS_ConvertUTF16toUTF8(mPreferredLang).get());
+#endif
+  }
+
+  // Auxiliary status.
+  nsresult rv2;
+
+  // We obtain a list of available dictionaries.
+  nsTArray<nsString> dictList;
+  rv2 = mSpellChecker->GetDictionaryList(&dictList);
+  NS_ENSURE_SUCCESS(rv2, rv2);
+
+  // Priority 1:
+  // If we successfully fetched a dictionary from content prefs, do not go
+  // further. Use this exact dictionary.
+  // Don't use content preferences for editor with eEditorMailMask flag.
+  nsAutoString dictName;
+  uint32_t flags;
+  mEditor->GetFlags(&flags);
+  if (!(flags & nsIPlaintextEditor::eEditorMailMask)) {
+    dictName.Assign(aFetcher->mDictionary);
+    if (!dictName.IsEmpty()) {
+      if (NS_SUCCEEDED(TryDictionary(dictName, dictList, DICT_NORMAL_COMPARE))) {
+#ifdef DEBUG_DICT
+        printf("***** Assigned from content preferences |%s|\n",
+               NS_ConvertUTF16toUTF8(dictName).get());
+#endif
+
+        // We take an early exit here, so let's not forget to clear the word
+        // list.
+        DeleteSuggestedWordList();
+        return NS_OK;
+      }
+      // May be dictionary was uninstalled ?
+      // Clear the content preference and continue.
+      ClearCurrentDictionary(mEditor);
+    }
+  }
+
+  // Priority 2:
+  // After checking the content preferences, we use the language of the element
+  // or document.
+  dictName.Assign(mPreferredLang);
+#ifdef DEBUG_DICT
+  printf("***** Assigned from element/doc |%s|\n",
+         NS_ConvertUTF16toUTF8(dictName).get());
+#endif
+
+  // Get the preference value.
+  nsAutoString preferredDict;
+  preferredDict = Preferences::GetLocalizedString("spellchecker.dictionary");
+
+  // The following will be driven by this status. Once we were able to set a
+  // dictionary successfully, we're done. So we start with a "failed" status.
+  nsresult rv = NS_ERROR_NOT_AVAILABLE;
+
+  if (!dictName.IsEmpty()) {
+    // RFC 5646 explicitly states that matches should be case-insensitive.
+    rv = TryDictionary (dictName, dictList, DICT_COMPARE_CASE_INSENSITIVE);
+
+    if (NS_FAILED(rv)) {
+#ifdef DEBUG_DICT
+      printf("***** Setting of |%s| failed (or it wasn't available)\n",
+             NS_ConvertUTF16toUTF8(dictName).get());
+#endif
+
+      // Required dictionary was not available. Try to get a dictionary
+      // matching at least language part of dictName.
+      nsAutoString langCode;
+      int32_t dashIdx = dictName.FindChar('-');
+      if (dashIdx != -1) {
+        langCode.Assign(Substring(dictName, 0, dashIdx));
+      } else {
+        langCode.Assign(dictName);
+      }
+
+      // Try dictionary.spellchecker preference, if it starts with langCode,
+      // so we don't just get any random dictionary matching the language.
+      if (!preferredDict.IsEmpty() &&
+          nsStyleUtil::DashMatchCompare(preferredDict, langCode, nsDefaultStringComparator())) {
+#ifdef DEBUG_DICT
+        printf("***** Trying preference value |%s| since it matches language code\n",
+               NS_ConvertUTF16toUTF8(preferredDict).get());
+#endif
+        rv = TryDictionary (preferredDict, dictList,
+                            DICT_COMPARE_CASE_INSENSITIVE);
+      }
+
+      if (NS_FAILED(rv)) {
+        // Use any dictionary with the required language.
+#ifdef DEBUG_DICT
+        printf("***** Trying to find match for language code |%s|\n",
+               NS_ConvertUTF16toUTF8(langCode).get());
+#endif
+        rv = TryDictionary (langCode, dictList, DICT_COMPARE_DASHMATCH);
+      }
+    }
+  }
+
+  // Priority 3:
+  // If the document didn't supply a dictionary or the setting failed,
+  // try the user preference next.
+  if (NS_FAILED(rv)) {
+    if (!preferredDict.IsEmpty()) {
+#ifdef DEBUG_DICT
+      printf("***** Trying preference value |%s|\n",
+             NS_ConvertUTF16toUTF8(preferredDict).get());
+#endif
+      rv = TryDictionary (preferredDict, dictList, DICT_NORMAL_COMPARE);
+    }
+  }
+
+  // Priority 4:
+  // As next fallback, try the current locale.
+  if (NS_FAILED(rv)) {
+    nsCOMPtr<nsIXULChromeRegistry> packageRegistry =
+      mozilla::services::GetXULChromeRegistryService();
+
+    if (packageRegistry) {
+      nsAutoCString utf8DictName;
+      rv2 = packageRegistry->GetSelectedLocale(NS_LITERAL_CSTRING("global"),
+                                               false, utf8DictName);
+      dictName.Assign(EmptyString());
+      AppendUTF8toUTF16(utf8DictName, dictName);
+#ifdef DEBUG_DICT
+      printf("***** Trying locale |%s|\n",
+             NS_ConvertUTF16toUTF8(dictName).get());
+#endif
+      rv = TryDictionary (dictName, dictList, DICT_COMPARE_CASE_INSENSITIVE);
+    }
+  }
+
+  if (NS_FAILED(rv)) {
+  // Still no success.
+
+  // Priority 5:
+  // If we have a current dictionary, don't try anything else.
+    nsAutoString currentDictionary;
+    rv2 = GetCurrentDictionary(currentDictionary);
+#ifdef DEBUG_DICT
+    if (NS_SUCCEEDED(rv2)) {
+        printf("***** Retrieved current dict |%s|\n",
+               NS_ConvertUTF16toUTF8(currentDictionary).get());
+    }
+#endif
+
+    if (NS_FAILED(rv2) || currentDictionary.IsEmpty()) {
+      // Priority 6:
+      // Try to get current dictionary from environment variable LANG.
+      // LANG = language[_territory][.charset]
+      char* env_lang = getenv("LANG");
+      if (env_lang) {
+        nsString lang = NS_ConvertUTF8toUTF16(env_lang);
+        // Strip trailing charset, if there is any.
+        int32_t dot_pos = lang.FindChar('.');
+        if (dot_pos != -1) {
+          lang = Substring(lang, 0, dot_pos);
+        }
+
+        int32_t underScore = lang.FindChar('_');
+        if (underScore != -1) {
+          lang.Replace(underScore, 1, '-');
+#ifdef DEBUG_DICT
+          printf("***** Trying LANG from environment |%s|\n",
+                 NS_ConvertUTF16toUTF8(lang).get());
+#endif
+          nsAutoString lang2;
+          lang2.Assign(lang);
+          rv = TryDictionary(lang2, dictList, DICT_COMPARE_CASE_INSENSITIVE);
+        }
+      }
+
+      // Priority 7:
+      // If it does not work, pick the first one.
+      if (NS_FAILED(rv) && !dictList.IsEmpty()) {
+        nsAutoString firstInList;
+        firstInList.Assign(dictList[0]);
+        rv = TryDictionary(firstInList, dictList, DICT_NORMAL_COMPARE);
+#ifdef DEBUG_DICT
+        printf("***** Trying first of list |%s|\n",
+               NS_ConvertUTF16toUTF8(dictList[0]).get());
+        if (NS_SUCCEEDED(rv)) {
+          printf ("***** Setting worked.\n");
+        }
+#endif
+      }
+    }
+  }
+
+  // If an error was thrown while setting the dictionary, just
+  // fail silently so that the spellchecker dialog is allowed to come
+  // up. The user can manually reset the language to their choice on
+  // the dialog if it is wrong.
+
+  DeleteSuggestedWordList();
+
+  return NS_OK;
+}