1 files changed, 26 insertions, 14 deletions
diff --git a/src/google/protobuf/util/internal/datapiece.cc b/src/google/protobuf/util/internal/datapiece.cc
index eeb55c6b..213c2c40 100644
--- a/src/google/protobuf/util/internal/datapiece.cc
+++ b/src/google/protobuf/util/internal/datapiece.cc
@@ -94,19 +94,24 @@ StatusOr<To> FloatingPointToIntConvertAndCheck(From before) {
 }
 
 // For conversion between double and float only.
-template <typename To, typename From>
-StatusOr<To> FloatingPointConvertAndCheck(From before) {
-  if (MathLimits<From>::IsNaN(before)) {
-    return std::numeric_limits<To>::quiet_NaN();
-  }
+StatusOr<double> FloatToDouble(float before) {
+  // Casting float to double should just work as double has more precision
+  // than float.
+  return static_cast<double>(before);
+}
 
-  To after = static_cast<To>(before);
-  if (MathUtil::AlmostEquals<To>(after, before)) {
-    return after;
+StatusOr<float> DoubleToFloat(double before) {
+  if (MathLimits<double>::IsNaN(before)) {
+    return std::numeric_limits<float>::quiet_NaN();
+  } else if (!MathLimits<double>::IsFinite(before)) {
+    // Converting a double +inf/-inf to float should just work.
+    return static_cast<float>(before);
+  } else if (before > std::numeric_limits<float>::max() ||
+             before < -std::numeric_limits<float>::max()) {
+    // Double value outside of the range of float.
+    return InvalidArgument(DoubleAsString(before));
   } else {
-    return InvalidArgument(::google::protobuf::internal::is_same<From, double>::value
-                               ? DoubleAsString(before)
-                               : FloatAsString(before));
+    return static_cast<float>(before);
   }
 }
 
@@ -162,20 +167,27 @@ StatusOr<uint64> DataPiece::ToUint64() const {
 
 StatusOr<double> DataPiece::ToDouble() const {
   if (type_ == TYPE_FLOAT) {
-    return FloatingPointConvertAndCheck<double, float>(float_);
+    return FloatToDouble(float_);
   }
   if (type_ == TYPE_STRING) {
     if (str_ == "Infinity") return std::numeric_limits<double>::infinity();
     if (str_ == "-Infinity") return -std::numeric_limits<double>::infinity();
     if (str_ == "NaN") return std::numeric_limits<double>::quiet_NaN();
-    return StringToNumber<double>(safe_strtod);
+    StatusOr<double> value = StringToNumber<double>(safe_strtod);
+    if (value.ok() && !MathLimits<double>::IsFinite(value.ValueOrDie())) {
+      // safe_strtod converts out-of-range values to +inf/-inf, but we want
+      // to report them as errors.
+      return InvalidArgument(StrCat("\"", str_, "\""));
+    } else {
+      return value;
+    }
   }
   return GenericConvert<double>();
 }
 
 StatusOr<float> DataPiece::ToFloat() const {
   if (type_ == TYPE_DOUBLE) {
-    return FloatingPointConvertAndCheck<float, double>(double_);
+    return DoubleToFloat(double_);
   }
   if (type_ == TYPE_STRING) {
     if (str_ == "Infinity") return std::numeric_limits<float>::infinity();