From ad61919ab684b1a6f7805f21ed911738b84c0697 Mon Sep 17 00:00:00 2001
From: Doug Davis <dug@us.ibm.com>
Date: Mon, 16 Mar 2015 22:23:40 -0700
Subject: [PATCH] Some fixed for new LABEL stuff

- command.Commands was missing "Label"
- used the correct error string in dispatcher when LABEL has no args, otherwise
  the test TestBuildMissingArgs will not work
- removed the premature error msg in line_parser that was blocking the
  label() func in dispatcher from showing the err msg in previous bullet
- since LABEL uses the env parser it needs to be added to the replaceEnvAllowed
  list so that proper quote processing will be done.  Especially once
  PR #10431 is merged.

Signed-off-by: Doug Davis <dug@us.ibm.com>
Upstream-commit: 6784a772baaa20936f00b8adc00a4b4444356181
Component: engine
---
 components/engine/builder/command/command.go     | 1 +
 components/engine/builder/dispatchers.go         | 2 +-
 components/engine/builder/evaluator.go           | 1 +
 components/engine/builder/parser/line_parsers.go | 2 +-
 4 files changed, 4 insertions(+), 2 deletions(-)

diff --git a/components/engine/builder/command/command.go b/components/engine/builder/command/command.go
index dd24ee44c5..16544f0267 100644
--- a/components/engine/builder/command/command.go
+++ b/components/engine/builder/command/command.go
@@ -22,6 +22,7 @@ const (
 // Commands is list of all Dockerfile commands
 var Commands = map[string]struct{}{
 	Env:        {},
+	Label:      {},
 	Maintainer: {},
 	Add:        {},
 	Copy:       {},
diff --git a/components/engine/builder/dispatchers.go b/components/engine/builder/dispatchers.go
index 965fd68c03..3cb3a9fb3a 100644
--- a/components/engine/builder/dispatchers.go
+++ b/components/engine/builder/dispatchers.go
@@ -91,7 +91,7 @@ func maintainer(b *Builder, args []string, attributes map[string]bool, original
 //
 func label(b *Builder, args []string, attributes map[string]bool, original string) error {
 	if len(args) == 0 {
-		return fmt.Errorf("LABEL is missing arguments")
+		return fmt.Errorf("LABEL requires at least one argument")
 	}
 	if len(args)%2 != 0 {
 		// should never get here, but just in case
diff --git a/components/engine/builder/evaluator.go b/components/engine/builder/evaluator.go
index aee60426c1..9808a3c42d 100644
--- a/components/engine/builder/evaluator.go
+++ b/components/engine/builder/evaluator.go
@@ -49,6 +49,7 @@ var (
 // Environment variable interpolation will happen on these statements only.
 var replaceEnvAllowed = map[string]struct{}{
 	command.Env:     {},
+	command.Label:   {},
 	command.Add:     {},
 	command.Copy:    {},
 	command.Workdir: {},
diff --git a/components/engine/builder/parser/line_parsers.go b/components/engine/builder/parser/line_parsers.go
index 06115e831a..45c929ee69 100644
--- a/components/engine/builder/parser/line_parsers.go
+++ b/components/engine/builder/parser/line_parsers.go
@@ -137,7 +137,7 @@ func parseNameVal(rest string, key string) (*Node, map[string]bool, error) {
 	}
 
 	if len(words) == 0 {
-		return nil, nil, fmt.Errorf(key + " requires at least one argument")
+		return nil, nil, nil
 	}
 
 	// Old format (KEY name value)