Verified Commit 9e8a90ef authored by Jonathan Kew's avatar Jonathan Kew Committed by ma1
Browse files

Bug 2045612 - Take ownership of the state in RestoreFormControlState. a=pascalc DONTBUILD 

Original Revision: https://phabricator.services.mozilla.com/D307613

Differential Revision: https://phabricator.services.mozilla.com/D307827
parent 046b2007

dom/html/nsGenericHTMLElement.cpp

+6 −5
Original line number Diff line number Diff line
@@ -3239,12 +3239,13 @@ bool nsGenericHTMLFormControlElementWithState::RestoreFormControlState() { 
    return false;

  }



  // Get the pres state for this key

  PresState* state = history->GetState(mStateKey);

  // Take ownership of the pres state for this key: RestoreState() can run

  // script (e.g. by synchronously committing an IME composition), which may

  // re-enter restoration for the same key and free a table-owned state while

  // we are still using it.

  UniquePtr<PresState> state = history->TakeState(mStateKey);

  if (state) {

    bool result = RestoreState(state);

    history->RemoveState(mStateKey);

    return result;

    return RestoreState(state.get());

  }



  return false;

layout/base/nsILayoutHistoryState.idl

+8 −0
Original line number Diff line number Diff line
@@ -80,6 +80,14 @@ interface nsILayoutHistoryState : nsISupports 
   */

  [noscript, notxpcom, nostdcall] void RemoveState(in nsCString aKey);



  /**

   * Remove the state object for |aKey| from the table and transfer

   * ownership of it to the caller. Use this instead of GetState() when

   * the state is consumed by code that may run script, so that a

   * re-entrant RemoveState()/Reset() cannot free it while in use.

   */

  [noscript, notxpcom, nostdcall] PresStateUnique TakeState(in nsCString aKey);



  /**

   * Check whether this history has any states in it

   */

layout/base/nsLayoutHistoryState.cpp

+15 −0
Original line number Diff line number Diff line
@@ -116,6 +116,21 @@ void nsLayoutHistoryState::RemoveState(const nsCString& aKey) { 
  mStates.Remove(aKey);

}



UniquePtr<PresState> nsLayoutHistoryState::TakeState(const nsCString& aKey) {

  UniquePtr<PresState> state;

  if (auto entry = mStates.Extract(aKey)) {

    state = std::move(*entry);

  }



  if (state && mScrollPositionOnly) {

    // Ensure any state that shouldn't be restored is removed

    state->contentData() = void_t();

    state->disabledSet() = false;

  }



  return state;

}



bool nsLayoutHistoryState::HasStates() { return mStates.Count() != 0; }



void nsLayoutHistoryState::SetScrollPositionOnly(const bool aFlag) {