Commit 06f40d59 authored by Jonathan Kew's avatar Jonathan Kew
Browse files

Bug 1879825 - Make Family::FindIndex fallible and safely handle failures.... 

Bug 1879825 - Make Family::FindIndex fallible and safely handle failures. r=gfx-reviewers,lsalzman, a=dsmith

Differential Revision: https://phabricator.services.mozilla.com/D201819
parent 2541acb6

gfx/thebes/SharedFontList.cpp

+23 −12
Original line number Diff line number Diff line
@@ -168,7 +168,11 @@ class SetCharMapRunnable : public mozilla::Runnable { 
void Face::SetCharacterMap(FontList* aList, gfxCharacterMap* aCharMap,

                           const Family* aFamily) {

  if (!XRE_IsParentProcess()) {

    std::pair<uint32_t, bool> familyIndex = aFamily->FindIndex(aList);

    Maybe<std::pair<uint32_t, bool>> familyIndex = aFamily->FindIndex(aList);

    if (!familyIndex) {

      NS_WARNING("Family index not found! Ignoring SetCharacterMap");

      return;

    }

    const auto* faces = aFamily->Faces(aList);

    uint32_t faceIndex = 0;

    while (faceIndex < aFamily->NumFaces()) {
@@ -177,14 +181,17 @@ void Face::SetCharacterMap(FontList* aList, gfxCharacterMap* aCharMap, 
      }

      ++faceIndex;

    }

    MOZ_RELEASE_ASSERT(faceIndex < aFamily->NumFaces(), "Face ptr not found!");

    if (faceIndex >= aFamily->NumFaces()) {

      NS_WARNING("Face not found in family! Ignoring SetCharacterMap");

      return;

    }

    if (NS_IsMainThread()) {

      dom::ContentChild::GetSingleton()->SendSetCharacterMap(

          aList->GetGeneration(), familyIndex.first, familyIndex.second,

          aList->GetGeneration(), familyIndex->first, familyIndex->second,

          faceIndex, *aCharMap);

    } else {

      NS_DispatchToMainThread(new SetCharMapRunnable(

          aList->GetGeneration(), familyIndex, faceIndex, aCharMap));

          aList->GetGeneration(), familyIndex.value(), faceIndex, aCharMap));

    }

    return;

  }
@@ -629,16 +636,20 @@ void Family::SetupFamilyCharMap(FontList* aList) { 
  if (!XRE_IsParentProcess()) {

    // |this| could be a Family record in either the Families() or Aliases()

    // arrays; FindIndex will map it back to its index and which array.

    std::pair<uint32_t, bool> index = FindIndex(aList);

    Maybe<std::pair<uint32_t, bool>> index = FindIndex(aList);

    if (!index) {

      NS_WARNING("Family index not found! Ignoring SetupFamilyCharMap");

      return;

    }

    if (NS_IsMainThread()) {

      dom::ContentChild::GetSingleton()->SendSetupFamilyCharMap(

          aList->GetGeneration(), index.first, index.second);

          aList->GetGeneration(), index->first, index->second);

      return;

    }

    NS_DispatchToMainThread(NS_NewRunnableFunction(

        "SetupFamilyCharMap callback",

        [gen = aList->GetGeneration(), idx = index.first,

         alias = index.second] {

        [gen = aList->GetGeneration(), idx = index->first,

         alias = index->second] {

          dom::ContentChild::GetSingleton()->SendSetupFamilyCharMap(gen, idx,

                                                                    alias);

        }));
@@ -685,13 +696,13 @@ void Family::SetupFamilyCharMap(FontList* aList) { 
  }

}



std::pair<uint32_t, bool> Family::FindIndex(FontList* aList) const {

Maybe<std::pair<uint32_t, bool>> Family::FindIndex(FontList* aList) const {

  const auto* start = aList->Families();

  const auto* end = start + aList->NumFamilies();

  if (this >= start && this < end) {

    uint32_t index = this - start;

    MOZ_RELEASE_ASSERT(start + index == this, "misaligned Family ptr!");

    return std::pair(index, false);

    return Some(std::pair(index, false));

  }



  start = aList->AliasFamilies();
@@ -699,10 +710,10 @@ std::pair<uint32_t, bool> Family::FindIndex(FontList* aList) const { 
  if (this >= start && this < end) {

    uint32_t index = this - start;

    MOZ_RELEASE_ASSERT(start + index == this, "misaligned AliasFamily ptr!");

    return std::pair(index, true);

    return Some(std::pair(index, true));

  }



  MOZ_CRASH("invalid font-list Family ptr!");

  return Nothing();

}



FontList::FontList(uint32_t aGeneration) {

gfx/thebes/SharedFontList.h

+2 −1
Original line number Diff line number Diff line
@@ -333,7 +333,8 @@ struct Family { 


  // Return the index of this family in the font-list's Families() or

  // AliasFamilies() list, and which of those it belongs to.

  std::pair<uint32_t, bool> FindIndex(FontList* aList) const;

  // Returns Nothing if the family cannot be found.

  mozilla::Maybe<std::pair<uint32_t, bool>> FindIndex(FontList* aList) const;



 private:

  // Returns true if there are specifically-sized bitmap faces in the list,