define-append now ignores empty values

e.g. define-append ABC 1 "" 2
will result in ABC="1 2"

Signed-off-by: Steve Bennett <steveb@workware.net.au>

autosetup

@@ -709,6 +709,9 @@ proc define-append {name args} {
 	if {[get-define $name ""] ne ""} {
 		# Avoid duplicates
 		foreach arg $args {
+			if {$arg eq ""} {
+				continue
+			}
 			set found 0
 			foreach str [split $::define($name) " "] {
 				if {$str eq $arg} {

testsuite/auto.def

@@ -81,8 +81,11 @@ test define-1.6 {define-append} {
 	define e {2 2}
 
 	# define-append will append with a space, omitting duplicates but not removing
-	define-append a 1 2
-	define-append b 1 2
+	# and will ignore empty values
+	define-append a 1 "" 2
+	define-append a ""
+	define-append a
+	define-append b "" 1 2
 	define-append c 1 2
 	define-append d 1 2
 	define-append e 1 2