fix(_comp_count_args): perform optarg check also on $3

The check that unconditionally accepts a word by a pattern has been
added by commits 75ec298 and 3809d95.  However, even if the word
matches the specified pattern, if the word is an option argument of
the previous option, it should not be counted as an argument.  This
patch changes the behavior so that it does not treat the word matching
$3 as an argument when it is an option argument.  The current use case
of $3 is only by chmod, where $2 is unspecified, so the behavior is
unaffected by this change.

bash_completion

@@ -2190,8 +2190,8 @@ _comp_count_args()
     ret=1
     for ((i = 1; i < cword; i++)); do
         # shellcheck disable=SC2053
-        if [[ ${words[i]} != -?* && ${words[i - 1]} != ${2-} ||
-            ${words[i]} == ${3-} ]]; then
+        if [[ (${words[i]} != -?* || ${words[i]} == ${3-}) &&
+            ${words[i - 1]} != ${2-} ]]; then
             ((ret++))
         elif [[ ${words[i]} == -- ]]; then
             ((ret += cword - i - 1))

test/t/unit/test_unit_count_args.py

@@ -90,3 +90,24 @@ def test_11_double_hyphen_2(self, bash):
         """all the words after -- should be counted"""
         output = self._test(bash, "(a b -- -c -d e)", 5, "a b -- -c -d e", 13)
         assert output == "4"
+
+    def test_12_exclude_optarg_1(self, bash):
+        """an option argument should be skipped even if it matches the argument pattern"""
+        output = self._test(
+            bash, "(a -o -x b c)", 4, "a -o -x b c", 10, arg='"" "-o" "-x"'
+        )
+        assert output == "2"
+
+    def test_12_exclude_optarg_2(self, bash):
+        """an option argument should be skipped even if it matches the argument pattern"""
+        output = self._test(
+            bash, "(a -o -x -x c)", 4, "a -o -x -x c", 11, arg='"" "-o" "-x"'
+        )
+        assert output == "2"
+
+    def test_12_exclude_optarg_3(self, bash):
+        """an option argument should be skipped even if it matches the argument pattern"""
+        output = self._test(
+            bash, "(a -o -x -y c)", 4, "a -o -x -y c", 11, arg='"" "-o" "-x"'
+        )
+        assert output == "1"