summaryrefslogtreecommitdiff
diff options
context:
space:
mode:
-rw-r--r--ChangeLog5
-rw-r--r--numeric.c8
2 files changed, 10 insertions, 3 deletions
diff --git a/ChangeLog b/ChangeLog
index eb76d689c0b..5358882f0ff 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,8 @@
+Thu Mar 5 18:36:38 2009 Nobuyoshi Nakada <nobu@ruby-lang.org>
+
+ * numeric.c (flo_to_s): keeps enough precision for round trip.
+ [ruby-core:22325]
+
Thu Mar 5 16:56:14 2009 Nobuyoshi Nakada <nobu@ruby-lang.org>
* lib/tmpdir.rb (Dir.tmpdir): not use USERPROFILE, and ignores
diff --git a/numeric.c b/numeric.c
index 2d6691de61f..bb554856695 100644
--- a/numeric.c
+++ b/numeric.c
@@ -521,7 +521,9 @@ rb_float_new(double d)
static VALUE
flo_to_s(VALUE flt)
{
- char buf[32];
+ enum {decimal_mant = DBL_MANT_DIG-DBL_DIG};
+ enum {float_dig = DBL_DIG+2};
+ char buf[float_dig + (decimal_mant + CHAR_BIT - 1) / CHAR_BIT + 10];
double value = RFLOAT_VALUE(flt);
char *p, *e;
@@ -530,12 +532,12 @@ flo_to_s(VALUE flt)
else if(isnan(value))
return rb_usascii_str_new2("NaN");
- snprintf(buf, sizeof(buf), "%#.15g", value); /* ensure to print decimal point */
+ snprintf(buf, sizeof(buf), "%#.*g", float_dig, value); /* ensure to print decimal point */
if (!(e = strchr(buf, 'e'))) {
e = buf + strlen(buf);
}
if (!ISDIGIT(e[-1])) { /* reformat if ended with decimal point (ex 111111111111111.) */
- snprintf(buf, sizeof(buf), "%#.14e", value);
+ snprintf(buf, sizeof(buf), "%#.*e", float_dig - 1, value);
if (!(e = strchr(buf, 'e'))) {
e = buf + strlen(buf);
}