by bcfabien:

What steps will reproduce the problem?

fmt.Fscanf appears to produce incorrect results when a newline is 
preceded by a space.

package main
import "fmt"
import "strings"
func main() {
  var z float64
  fmt.Printf("unexpected result\n")
  in := strings.NewReader(" 1.1 1.2 1.3 \n 2.4 2.5 2.6 \n 3.7 3.8 3.9 ")
  for i := 0; i < 9; i++ {
      fmt.Fscanf(in, "%e", &z) // throws "unexpected newline"
      fmt.Printf(" %g ", z)
  }
  fmt.Printf("\n")
  fmt.Printf("expected result\n")
  in = strings.NewReader(" 1.1 1.2 1.3\n 2.4 2.5 2.6\n 3.7 3.8 3.9")
  for i := 0; i < 9; i++ {
      fmt.Fscanf(in, "%e", &z)
      fmt.Printf(" %g ", z)
  }
  fmt.Printf("\n")
}

What is the expected output?

expected result
 1.1  1.2  1.3  2.4  2.5  2.6  3.7  3.8  3.9

What do you see instead?

unexpected result
 1.1  1.2  1.3  1.3  2.4  2.5  2.6  2.6  3.7 
 
What is your $GOOS?  $GOARCH?

GOARCH=amd64
GOOS=darwin

Which revision are you using?  (hg identify)

localhost:go $ hg summary
parent: 5812:5992bf56aa72 release.2010-07-14 release
 release.2010-07-14
branch: default
commit: 1 unknown (clean)
update: 54 new changesets (update)

Please provide any additional information below.