libmakepkg: fix empty arguments in parseopts

Previously parseopts checked if there was an argument by checking
that the string was non-empty, resulting in empty arguments being
incorrectly considered non-existent. This change makes parseopts check
if arguments exist at all, rather than checking that they are non-empty

Signed-off-by: Ethan Sommer <e5ten.arch@gmail.com>
Signed-off-by: Allan McRae <allan@archlinux.org>

scripts/libmakepkg/util/parseopts.sh.in

@@ -103,7 +103,7 @@ parseopts() {
 								OPTRET+=("-$opt" "${1:i+1}")
 								break
 							# if we're at the end, grab the the next positional, if it exists
-							elif (( i == ${#1} - 1 )) && [[ $2 ]]; then
+							elif (( i == ${#1} - 1 && $# > 1 )); then
 								OPTRET+=("-$opt" "$2")
 								shift
 								break
@@ -144,7 +144,7 @@ parseopts() {
 				case $? in
 					0)
 						# parse failure
-						if [[ $optarg ]]; then
+						if [[ $1 = *=* ]]; then
 							printf "${0##*/}: $(gettext "option '%s' does not allow an argument")\n" "--$opt" >&2
 							OPTRET=(--)
 							return 1
@@ -155,10 +155,10 @@ parseopts() {
 						;;
 					1)
 						# --longopt=optarg
-						if [[ $optarg ]]; then
+						if [[ $1 = *=* ]]; then
 							OPTRET+=("--$opt" "$optarg")
 						# --longopt optarg
-						elif [[ $2 ]]; then
+						elif (( $# > 1 )); then
 							OPTRET+=("--$opt" "$2" )
 							shift
 						# parse failure

test/scripts/parseopts_test.sh

@@ -31,7 +31,7 @@ tap_parse() {
 	unset OPTRET
 }
 
-tap_plan 54
+tap_plan 56
 
 # usage: tap_parse <expected result> <token count> test-params...
 # a failed tap_parse will match only the end of options marker '--'
@@ -117,4 +117,7 @@ tap_parse '--opt= --opt=foo --opt --' 4 --opt= --opt=foo --opt
 # short opt with and without optional arg, and non-option arg
 tap_parse '-b=foo -A -b -- foo' 5 -bfoo -Ab foo
 
+# all possible ways to specify empty optargs
+tap_parse '--key  --pkg  -p  --' 7 --key '' --pkg='' -p ''
+
 tap_finish