fmt: mishandling of FALSE in Scanf

[gopherbot]

by toqueteos:

What steps will reproduce the problem?
1. Reading from stdin a bool value using fmt.Scanf with %t
2. Write FLLSE
3. It works?!

What is the expected output?
Not a boolean value but is evaluated as false.

What do you see instead?
A falsy value.

Which compiler are you using (5g, 6g, 8g, gccgo)?
6g

Which operating system are you using?
Linux & Windows

Which revision are you using?  (hg identify)
go version weekly.2011-12-22 11071

Please provide any additional information below.

The error is located here
http://code.google.com/p/go/source/browse/src/pkg/fmt/scan.go#515

That first accept should be s.accept("aA") instead of s.accept("aL")

[rsc]

Comment 1:

I think you have to scan two elements to detect the bug,
because the leading "F" counts as false no matter what.

Labels changed: added priority-go1, go1-must, removed priority-triage.

Owner changed to builder@golang.org.

Status changed to Accepted.

[robpike]

Comment 2:

Status changed to WorkingAsIntended.

[rsc]

Comment 3:

I'm pretty sure there's a bug here, as pointed out:
s/aL/aA/.
My comment was about testing for the bug.  I had a hard
time writing a quick test that would break before applying
the fix.  I thought it would be a 1-minute job.

Owner changed to @robpike.

Status changed to Accepted.

[robpike]

Comment 4:

There is a bug in that accept call but as written the program is not a test for it.

[robpike]

Comment 5:

This issue was closed by revision c0e74b6.

Status changed to Fixed.