strconv: fix %.1f, 0.09
Fixes #822.
Credit to https://golang.org/cl/1442041 by danielfleischman
R=rsc
CC=golang-dev
https://golang.org/cl/1738047
diff --git a/src/pkg/strconv/decimal.go b/src/pkg/strconv/decimal.go
index b334851..3be61d7 100644
--- a/src/pkg/strconv/decimal.go
+++ b/src/pkg/strconv/decimal.go
@@ -289,11 +289,11 @@
// If we chop a at nd digits, should we round up?
func shouldRoundUp(a *decimal, nd int) bool {
- if nd <= 0 || nd >= a.nd {
+ if nd < 0 || nd >= a.nd {
return false
}
if a.d[nd] == '5' && nd+1 == a.nd { // exactly halfway - round to even
- return (a.d[nd-1]-'0')%2 != 0
+ return nd > 0 && (a.d[nd-1]-'0')%2 != 0
}
// not halfway - digit tells all
return a.d[nd] >= '5'
@@ -301,8 +301,11 @@
// Round a to nd digits (or fewer).
// Returns receiver for convenience.
+// If nd is zero, it means we're rounding
+// just to the left of the digits, as in
+// 0.09 -> 0.1.
func (a *decimal) Round(nd int) *decimal {
- if nd <= 0 || nd >= a.nd {
+ if nd < 0 || nd >= a.nd {
return a
}
if shouldRoundUp(a, nd) {
@@ -314,7 +317,7 @@
// Round a down to nd digits (or fewer).
// Returns receiver for convenience.
func (a *decimal) RoundDown(nd int) *decimal {
- if nd <= 0 || nd >= a.nd {
+ if nd < 0 || nd >= a.nd {
return a
}
a.nd = nd
@@ -325,7 +328,7 @@
// Round a up to nd digits (or fewer).
// Returns receiver for convenience.
func (a *decimal) RoundUp(nd int) *decimal {
- if nd <= 0 || nd >= a.nd {
+ if nd < 0 || nd >= a.nd {
return a
}
