Fix #8352: std domain: Failed to parse an option that starts with bracket

CHANGES

@@ -70,6 +70,7 @@ Bugs fixed
 * #8131: linkcheck: Use GET when HEAD requests cause Too Many Redirects, to
   accommodate infinite redirect loops on HEAD
 * #8437: Makefile: ``make clean`` with empty BUILDDIR is dangerous
+* #8352: std domain: Failed to parse an option that starts with bracket
 
 Testing
 --------

sphinx/domains/std.py

@@ -43,7 +43,7 @@ logger = logging.getLogger(__name__)
 
 
 # RE for option descriptions
-option_desc_re = re.compile(r'((?:/|--|-|\+)?[^\s=[]+)(=?\s*.*)')
+option_desc_re = re.compile(r'((?:/|--|-|\+)?[^\s=]+)(=?\s*.*)')
 # RE for grammar tokens
 token_re = re.compile(r'`(\w+)`', re.U)
 
@@ -197,6 +197,11 @@ class Cmdoption(ObjectDescription):
                                location=signode)
                 continue
             optname, args = m.groups()
+            if optname.endswith('[') and args.endswith(']'):
+                # optional value surrounded by brackets (ex. foo[=bar])
+                optname = optname[:-1]
+                args = '[' + args
+
             if count:
                 signode += addnodes.desc_addname(', ', ', ')
             signode += addnodes.desc_name(optname, optname)

tests/test_domain_std.py

@@ -91,6 +91,28 @@ def test_get_full_qualified_name():
     assert domain.get_full_qualified_name(node) == 'ls.-l'
 
 
+def test_cmd_option_with_optional_value(app):
+    text = ".. option:: -j[=N]"
+    doctree = restructuredtext.parse(app, text)
+    assert_node(doctree, (index,
+                          [desc, ([desc_signature, ([desc_name, '-j'],
+                                                    [desc_addname, '[=N]'])],
+                                  [desc_content, ()])]))
+    objects = list(app.env.get_domain("std").get_objects())
+    assert ('-j', '-j', 'cmdoption', 'index', 'cmdoption-j', 1) in objects
+
+
+def test_cmd_option_starting_with_bracket(app):
+    text = ".. option:: [enable=]PATTERN"
+    doctree = restructuredtext.parse(app, text)
+    assert_node(doctree, (index,
+                          [desc, ([desc_signature, ([desc_name, '[enable'],
+                                                    [desc_addname, '=]PATTERN'])],
+                                  [desc_content, ()])]))
+    objects = list(app.env.get_domain("std").get_objects())
+    assert ('[enable', '[enable', 'cmdoption', 'index', 'cmdoption-arg-enable', 1) in objects
+
+
 def test_glossary(app):
     text = (".. glossary::\n"
             "\n"