ported from UXP: Issue #2713 - Check for NaN before std::min/max() in DOMQuad and DOMRect. (f1c456c6)

dom/base/DOMQuad.cpp

@@ -10,7 +10,7 @@
 #include "mozilla/dom/DOMPoint.h"
 #include "mozilla/dom/DOMRect.h"
 #include "mozilla/dom/DOMRectBinding.h"
-#include <algorithm>
+#include "mozilla/FloatingPoint.h"
 
 using namespace mozilla;
 using namespace mozilla::dom;
@@ -108,8 +108,8 @@ DOMQuad::GetHorizontalMinMax(double* aX1, double* aX2) const
   x1 = x2 = Point(0)->X();
   for (uint32_t i = 1; i < 4; ++i) {
     double x = Point(i)->X();
-    x1 = std::min(x1, x);
-    x2 = std::max(x2, x);
+    x1 = NaNSafeMin(x1, x);
+    x2 = NaNSafeMax(x2, x);
   }
   *aX1 = x1;
   *aX2 = x2;
@@ -122,8 +122,8 @@ DOMQuad::GetVerticalMinMax(double* aY1, double* aY2) const
   y1 = y2 = Point(0)->Y();
   for (uint32_t i = 1; i < 4; ++i) {
     double y = Point(i)->Y();
-    y1 = std::min(y1, y);
-    y2 = std::max(y2, y);
+    y1 = NaNSafeMin(y1, y);
+    y2 = NaNSafeMax(y2, y);
   }
   *aY1 = y1;
   *aY2 = y2;

dom/base/DOMRect.h

@@ -17,7 +17,7 @@
 #include "mozilla/Attributes.h"
 #include "mozilla/dom/BindingDeclarations.h"
 #include "mozilla/ErrorResult.h"
-#include <algorithm>
+#include "mozilla/FloatingPoint.h"
 
 struct nsRect;
 
@@ -80,22 +80,22 @@ public:
   double Left() const
   {
     double x = X(), w = Width();
-    return std::min(x, x + w);
+    return NaNSafeMin(x, x + w);
   }
   double Top() const
   {
     double y = Y(), h = Height();
-    return std::min(y, y + h);
+    return NaNSafeMin(y, y + h);
   }
   double Right() const
   {
     double x = X(), w = Width();
-    return std::max(x, x + w);
+    return NaNSafeMax(x, x + w);
   }
   double Bottom() const
   {
     double y = Y(), h = Height();
-    return std::max(y, y + h);
+    return NaNSafeMax(y, y + h);
   }
 
   bool WriteStructuredClone(JSStructuredCloneWriter* aWriter) const;

mfbt/FloatingPoint.h

@@ -15,6 +15,7 @@
 #include "mozilla/MathAlgorithms.h"
 #include "mozilla/Types.h"
 
+#include <algorithm>
 #include <stdint.h>
 
 namespace mozilla {
@@ -451,6 +452,30 @@ EqualOrBothNaN(T aValue1, T aValue2)
   return aValue1 == aValue2;
 }
 
+/**
+ * Return NaN if either |aValue1| or |aValue2| is NaN, or the minimum of
+ * |aValue1| and |aValue2| otherwise.
+ */
+template <typename T>
+static inline T NaNSafeMin(T aValue1, T aValue2) {
+  if (IsNaN(aValue1) || IsNaN(aValue2)) {
+    return UnspecifiedNaN<T>();
+  }
+  return std::min(aValue1, aValue2);
+}
+
+/**
+ * Return NaN if either |aValue1| or |aValue2| is NaN, or the maximum of
+ * |aValue1| and |aValue2| otherwise.
+ */
+template <typename T>
+static inline T NaNSafeMax(T aValue1, T aValue2) {
+  if (IsNaN(aValue1) || IsNaN(aValue2)) {
+    return UnspecifiedNaN<T>();
+  }
+  return std::max(aValue1, aValue2);
+}
+
 namespace detail {
 
 template<typename T>