fix(_comp_{first_arg,count_args}): count - as argument

bash_completion

@@ -2165,7 +2165,7 @@ _comp_get_first_arg()
 
     arg=
     for ((i = 1; i < cword; i++)); do
-        if [[ ${words[i]} != -* ]]; then
+        if [[ ${words[i]} != -?* ]]; then
             arg=${words[i]}
             break
         fi
@@ -2187,7 +2187,7 @@ _comp_count_args()
     ret=1
     for ((i = 1; i < cword; i++)); do
         # shellcheck disable=SC2053
-        if [[ ${words[i]} != -* && ${words[i - 1]} != ${2-} ||
+        if [[ ${words[i]} != -?* && ${words[i - 1]} != ${2-} ||
             ${words[i]} == ${3-} ]]; then
             ((ret++))
         fi

bash_completion.d/000_bash_completion_compat.bash

@@ -423,12 +423,21 @@ _get_first_arg()
 # @var[out] args   Return the number of arguments
 # @deprecated 2.12 Use `_comp_count_args`.  Note that the new function
 # `_comp_count_args` returns the result in variable `ret` instead of `args`.
+# In the new function, `-` is also counted as an argument.
+# shellcheck disable=SC2178 # assignments are not intended for global "args"
 _count_args()
 {
-    local ret
-    _comp_count_args "$@"
-    # shellcheck disable=SC2178
-    args=$ret
+    local i cword words
+    _comp__reassemble_words "${1-}" words cword
+
+    args=1
+    for ((i = 1; i < cword; i++)); do
+        # shellcheck disable=SC2053
+        if [[ ${words[i]} != -* && ${words[i - 1]} != ${2-} ||
+            ${words[i]} == ${3-} ]]; then
+            ((args++))
+        fi
+    done
 }
 
 # ex: filetype=sh

test/t/unit/test_unit_count_args.py

@@ -66,3 +66,15 @@ def test_9(self, bash):
             bash, "(a -b -c d e)", 4, "a -b -c d e", 11, arg='"" "" "-b"'
         )
         assert output == "3"
+
+    def test_10_single_hyphen_1(self, bash):
+        """- should be counted as an argument representing stdout/stdin"""
+        output = self._test(bash, "(a -b - c -d e)", 5, "a -b - c -d e", 12)
+        assert output == "3"
+
+    def test_10_single_hyphen_2(self, bash):
+        """- in an option argument should be skipped"""
+        output = self._test(
+            bash, "(a -b - c - e)", 5, "a -b - c - e", 11, arg='"" "-b"'
+        )
+        assert output == "3"

test/t/unit/test_unit_get_first_arg.py

@@ -48,3 +48,10 @@ def test_6(self, bash, functions):
             bash, '_comp__test_unit "(a -b -c d e)" 4', want_output=None
         ).strip()
         assert output == "d"
+
+    def test_7_single_hyphen(self, bash, functions):
+        """- should be counted as an argument representing stdout/stdin"""
+        output = assert_bash_exec(
+            bash, '_comp__test_unit "(a -b - c -d e)" 5', want_output=None
+        ).strip()
+        assert output == "-"