diff options
| author | jimmyfrasche <soapboxcicero@gmail.com> | 2018-04-01 11:15:17 -0700 |
|---|---|---|
| committer | Brad Fitzpatrick <bradfitz@golang.org> | 2018-04-01 20:17:22 +0000 |
| commit | 3c588b3fe7e1394f7df981284f1dc4c0a2b32b14 (patch) | |
| tree | 2b092e5a839d20b854f447ded0069d986b8253f2 /src/flag | |
| parent | e55475ca3b6652d2d24b7bf48bcaf3e216c3ed68 (diff) | |
| download | go-3c588b3fe7e1394f7df981284f1dc4c0a2b32b14.tar.gz go-3c588b3fe7e1394f7df981284f1dc4c0a2b32b14.zip | |
flag: correct zero values when printing defaults
When the flag package first begin printing nonzero defaults, the test
was against a fixed set of string representations of zero values.
This worked until the string representation of a time.Duration
changed from "0" to "0s", causing the zero Duration to register as
nonzero. The flag package then added reflect-based code that fell back
to the old test. This failed to work when a nonzero default for a flag
happened to be the string representation of one the original fixed set
of zero values in the original test. This change removes the original
test, allowing the reflect-based code to be the only deciding factor.
Fixes #23543
Change-Id: I582ce554d6729e336fdd96fb27340674c15350d8
Reviewed-on: https://go-review.googlesource.com/103867
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
Run-TryBot: Brad Fitzpatrick <bradfitz@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Diffstat (limited to 'src/flag')
| -rw-r--r-- | src/flag/flag.go | 14 | ||||
| -rw-r--r-- | src/flag/flag_test.go | 3 |
2 files changed, 6 insertions, 11 deletions
diff --git a/src/flag/flag.go b/src/flag/flag.go index 358402345c..f613144a7e 100644 --- a/src/flag/flag.go +++ b/src/flag/flag.go @@ -395,8 +395,8 @@ func Set(name, value string) error { return CommandLine.Set(name, value) } -// isZeroValue guesses whether the string represents the zero -// value for a flag. It is not accurate but in practice works OK. +// isZeroValue determines whether the string represents the zero +// value for a flag. func isZeroValue(flag *Flag, value string) bool { // Build a zero value of the flag's Value type, and see if the // result of calling its String method equals the value passed in. @@ -408,15 +408,7 @@ func isZeroValue(flag *Flag, value string) bool { } else { z = reflect.Zero(typ) } - if value == z.Interface().(Value).String() { - return true - } - - switch value { - case "false", "", "0": - return true - } - return false + return value == z.Interface().(Value).String() } // UnquoteUsage extracts a back-quoted name from the usage diff --git a/src/flag/flag_test.go b/src/flag/flag_test.go index 67c409f29b..c7f0c07d44 100644 --- a/src/flag/flag_test.go +++ b/src/flag/flag_test.go @@ -386,6 +386,8 @@ const defaultOutput = ` -A for bootstrapping, allow 'any' type -C a boolean defaulting to true (default true) -D path set relative path for local imports + -E string + issue 23543 (default "0") -F number a non-zero number (default 2.7) -G float @@ -412,6 +414,7 @@ func TestPrintDefaults(t *testing.T) { fs.Bool("Alongflagname", false, "disable bounds checking") fs.Bool("C", true, "a boolean defaulting to true") fs.String("D", "", "set relative `path` for local imports") + fs.String("E", "0", "issue 23543") fs.Float64("F", 2.7, "a non-zero `number`") fs.Float64("G", 0, "a float that defaults to zero") fs.String("M", "", "a multiline\nhelp\nstring") |