correct the fixed-mode halfway example in the dtoa headers

double-conversion/bignum-dtoa.h

@@ -64,8 +64,8 @@ enum BignumDtoaMode {
 //   'requested_digits' digits after the decimal point. The produced digits
 //   might be too short in which case the caller has to fill the gaps with '0's.
 //   Example: toFixed(0.001, 5) is allowed to return buffer="1", point=-2.
-//   Halfway cases are rounded up. The call toFixed(0.15, 2) thus returns
-//     buffer="2", point=0.
+//   Halfway cases are rounded up. The call toFixed(0.25, 1) thus returns
+//     buffer="3", point=0.
 //   Note: the length of the returned buffer has no meaning wrt the significance
 //   of its digits. That is, just because it contains '0's does not mean that
 //   any other digit would not satisfy the internal identity requirement.

double-conversion/double-to-string.h

@@ -436,7 +436,7 @@ class DoubleToStringConverter {
   //   with '0's.
   //   Example: toFixed(0.001, 5) is allowed to return buffer="1", point=-2.
   //   Halfway cases are rounded towards +/-Infinity (away from 0). The call
-  //   toFixed(0.15, 2) thus returns buffer="2", point=0.
+  //   toFixed(0.25, 1) thus returns buffer="3", point=0.
   //   The returned buffer may contain digits that would be truncated from the
   //   shortest representation of the input.
   //  - PRECISION: produces 'requested_digits' where the first digit is not '0'.

double-conversion/fixed-dtoa.h

@@ -42,7 +42,7 @@ namespace double_conversion {
 // Example: FastFixedDtoa(0.001, 5, ...) is allowed to return buffer = "1", and
 // decimal_point = -2.
 // Halfway cases are rounded towards +/-Infinity (away from 0). The call
-// FastFixedDtoa(0.15, 2, ...) thus returns buffer = "2", decimal_point = 0.
+// FastFixedDtoa(0.25, 1, ...) thus returns buffer = "3", decimal_point = 0.
 // The returned buffer may contain digits that would be truncated from the
 // shortest representation of the input.
 //

test/cctest/test-bignum-dtoa.cc

@@ -93,6 +93,12 @@ TEST(BignumDtoaVariousDoubles) {
   CHECK_EQ("15", buffer.start());
   CHECK_EQ(1, point);
 
+  BignumDtoa(0.25, BIGNUM_DTOA_FIXED, 1, buffer, &length, &point);
+  CHECK_GE(1, length - point);
+  TrimRepresentation(buffer);
+  CHECK_EQ("3", buffer.start());
+  CHECK_EQ(0, point);
+
   double min_double = 5e-324;
   BignumDtoa(min_double, BIGNUM_DTOA_SHORTEST, 0, buffer, &length, &point);
   CHECK_EQ("5", buffer.start());

test/cctest/test-fixed-dtoa.cc

@@ -438,6 +438,10 @@ TEST(FastFixedVariousDoubles) {
   CHECK_EQ("1", buffer.start());
   CHECK_EQ(1, point);
 
+  CHECK(FastFixedDtoa(0.25, 1, buffer, &length, &point));
+  CHECK_EQ("3", buffer.start());
+  CHECK_EQ(0, point);
+
   CHECK(FastFixedDtoa(1e-23, 10, buffer, &length, &point));
   CHECK_EQ("", buffer.start());
   CHECK_EQ(-10, point);