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at 2024-08-31T13:56:21+08:00

Bug 1885101: Match screen and window properties with top window for ScreenRect, ScreenAvailRect and WindowOuterSize. r=timhuang,emilio

This patch removes test_iframe.html. We remove it because the newly introduced test covers the tests done in that test. The reason for removing it in the first place is now that screen properties are inherited/spoofed xorigin, we get a 4px difference. The reasosn for 4px difference is the test runner runs tests in an iframe with a 2px border on each side.

Differential Revision: https://phabricator.services.mozilla.com/D215509

@@ -32,6 +32,9 @@
  #include "nsILoadInfo.h"
  #include "nsILoadContext.h"
  #include "nsThreadUtils.h"
 +// It seems ESR-115 is missing the definitions of CSSIntSize, so add this
 +// header to include it
 +#include "Units.h"
  class nsDocShellLoadState;
  class nsGlobalWindowInner;
@@ -266,7 +269,10 @@ struct EmbedderColorSchemes {
     * a content process. */                                                    \
    FIELD(EmbeddedInContentDocument, bool)                                      \
    /* If true, this browsing context is within a hidden embedded document. */  \
 -  FIELD(IsUnderHiddenEmbedderElement, bool)
 +  FIELD(IsUnderHiddenEmbedderElement, bool)                                   \
 +  /* Used to propagate window.top's inner size for RFPTarget::Window*         \
 +   * protections */                                                           \
 +  FIELD(TopInnerSizeForRFP, mozilla::CSSIntSize)
  // BrowsingContext, in this context, is the cross process replicated
  // environment in which information about documents is stored. In
@@ -1231,6 +1237,10 @@ class BrowsingContext : public nsILoadContext, public nsWrapperCache {
                const bool& aIsUnderHiddenEmbedderElement,
                ContentParent* aSource);
 +  bool CanSet(FieldIndex<IDX_TopInnerSizeForRFP>, bool, ContentParent*) {
 +    return IsTop();
 +  }
++
    bool CanSet(FieldIndex<IDX_EmbeddedInContentDocument>, bool,
                ContentParent* aSource) {
      return CheckOnlyEmbedderCanSet(aSource);

@@ -318,6 +318,7 @@ void CanonicalBrowsingContext::ReplacedBy(
    txn.SetEmbedderColorSchemes(GetEmbedderColorSchemes());
    txn.SetHasRestoreData(GetHasRestoreData());
    txn.SetShouldDelayMediaFromStart(GetShouldDelayMediaFromStart());
 +  txn.SetTopInnerSizeForRFP(GetTopInnerSizeForRFP());
    // Propagate some settings on BrowsingContext replacement so they're not lost
    // on bfcached navigations. These are important for GeckoView (see bug

@@ -3581,9 +3581,10 @@ CSSIntSize nsGlobalWindowOuter::GetOuterSize(CallerType aCallerType,
                                               ErrorResult& aError) {
    if (nsIGlobalObject::ShouldResistFingerprinting(aCallerType,
                                                    RFPTarget::Unknown)) {
 -    CSSSize size;
 -    aError = GetInnerSize(size);
 -    return RoundedToInt(size);
 +    if (BrowsingContext* bc = GetBrowsingContext()) {
 +      return bc->Top()->GetTopInnerSizeForRFP();
 +    }
 +    return {};
+   }
    // Windows showing documents in RDM panes and any subframes within them

@@ -81,7 +81,7 @@ nsDeviceContext* nsScreen::GetDeviceContext() const {
  nsresult nsScreen::GetRect(CSSIntRect& aRect) {
    // Return window inner rect to prevent fingerprinting.
    if (ShouldResistFingerprinting()) {
 -    return GetWindowInnerRect(aRect);
 +    return GetTopWindowInnerRectForRFP(aRect);
+   }
    // Here we manipulate the value of aRect to represent the screen size,
@@ -113,7 +113,7 @@ nsresult nsScreen::GetRect(CSSIntRect& aRect) {
  nsresult nsScreen::GetAvailRect(CSSIntRect& aRect) {
    // Return window inner rect to prevent fingerprinting.
    if (ShouldResistFingerprinting()) {
 -    return GetWindowInnerRect(aRect);
 +    return GetTopWindowInnerRectForRFP(aRect);
+   }
    // Here we manipulate the value of aRect to represent the screen size,
@@ -208,20 +208,14 @@ JSObject* nsScreen::WrapObject(JSContext* aCx,
    return Screen_Binding::Wrap(aCx, this, aGivenProto);
+ }
 -nsresult nsScreen::GetWindowInnerRect(CSSIntRect& aRect) {
 -  aRect.x = 0;
 -  aRect.y = 0;
 -  nsCOMPtr<nsPIDOMWindowInner> win = GetOwner();
 -  if (!win) {
 -    return NS_ERROR_FAILURE;
 +nsresult nsScreen::GetTopWindowInnerRectForRFP(CSSIntRect& aRect) {
 +  aRect = {};
 +  if (nsPIDOMWindowInner* inner = GetOwner()) {
 +    if (BrowsingContext* bc = inner->GetBrowsingContext()) {
 +      CSSIntSize size = bc->Top()->GetTopInnerSizeForRFP();
 +      aRect = {0, 0, size.width, size.height};
 +    }
+   }
 -  double width;
 -  double height;
 -  nsresult rv = win->GetInnerWidth(&width);
 -  NS_ENSURE_SUCCESS(rv, rv);
 -  rv = win->GetInnerHeight(&height);
 -  NS_ENSURE_SUCCESS(rv, rv);
 -  aRect.SizeTo(std::round(width), std::round(height));
    return NS_OK;
+ }

@@ -127,7 +127,9 @@ class nsScreen : public mozilla::DOMEventTargetHelper {
    nsDeviceContext* GetDeviceContext() const;
    nsresult GetRect(mozilla::CSSIntRect& aRect);
    nsresult GetAvailRect(mozilla::CSSIntRect& aRect);
 -  nsresult GetWindowInnerRect(mozilla::CSSIntRect& aRect);
 +  // Sometime between ESR-115 and ESR-128 the function signature changed, so we
 +  // revert to the ESR-115 way of doing things
 +  nsresult GetTopWindowInnerRectForRFP(mozilla::CSSIntRect& aRect);
   private:
    explicit nsScreen(nsPIDOMWindowInner* aWindow);

ma1 pushed to branch mullvad-browser-115.15.0esr-13.5-1 at The Tor Project / Applications / Mullvad Browser

Commits:

7 changed files:

Changes:

@@ -1448,6 +1448,26 @@ void nsPresContext::SetOverrideDPPX(float aDPPX) {
                              MediaFeatureChangePropagation::JustThisDocument);
+ }
 +void nsPresContext::UpdateTopInnerSizeForRFP() {
 +// RFPTarget::WindowOuterSize does not exist in ESR-115 so use fallback
 +  if (!mDocument->ShouldResistFingerprinting(RFPTarget::Unknown) ||
 +      !mDocument->GetBrowsingContext() ||
 +      !mDocument->GetBrowsingContext()->IsTop()) {
 +    return;
 +  }
++
 +  CSSSize size = CSSPixel::FromAppUnits(GetVisibleArea().Size());
++
 +  // The upstream version of this patch had conditional logic based on the
 +  // dom.innerSize.rounding pref which does not exist in ESR-115, so we
 +  // pick the branch it would have taken for the pref's default value (2)
 +  size.width = std::truncf(size.width);
 +  size.height = std::truncf(size.height);
++
 +  Unused << mDocument->GetBrowsingContext()->SetTopInnerSizeForRFP(
 +      CSSIntSize{(int)size.width, (int)size.height});
 +}
++
  gfxSize nsPresContext::ScreenSizeInchesForFontInflation(bool* aChanged) {
    if (aChanged) {
      *aChanged = false;
@@ -2979,6 +2999,8 @@ void nsPresContext::SetVisibleArea(const nsRect& r) {
            {mozilla::MediaFeatureChangeReason::ViewportChange},
            MediaFeatureChangePropagation::JustThisDocument);
+     }
++
 +    UpdateTopInnerSizeForRFP();
+   }
+ }

@@ -549,6 +549,7 @@ class nsPresContext : public nsISupports, public mozilla::SupportsWeakPtr {
    void SetFullZoom(float aZoom);
    void SetOverrideDPPX(float);
    void SetInRDMPane(bool aInRDMPane);
 +  void UpdateTopInnerSizeForRFP();
   public:
    float GetFullZoom() { return mFullZoom; }