diff --git a/Grammar/python.gram b/Grammar/python.gram
index 315f12fe00282b2..28f5ed3a6e61d4a 100644
--- a/Grammar/python.gram
+++ b/Grammar/python.gram
@@ -555,12 +555,12 @@ complex_number[expr_ty]:
 
 signed_number[expr_ty]:
     | NUMBER
-    | '+' number=NUMBER { number }
+    | '+' number=NUMBER { _PyAST_UnaryOp(UAdd, number, EXTRA) }
     | '-' number=NUMBER { _PyAST_UnaryOp(USub, number, EXTRA) }
 
 signed_real_number[expr_ty]:
     | real_number
-    | '+' real=real_number { real }
+    | '+' real=real_number { _PyAST_UnaryOp(UAdd, real, EXTRA) }
     | '-' real=real_number { _PyAST_UnaryOp(USub, real, EXTRA) }
 
 real_number[expr_ty]:
diff --git a/Lib/idlelib/idle_test/test_iomenu.py b/Lib/idlelib/idle_test/test_iomenu.py
index 90a23620354f313..3ef9fcbc5bb569b 100644
--- a/Lib/idlelib/idle_test/test_iomenu.py
+++ b/Lib/idlelib/idle_test/test_iomenu.py
@@ -1,11 +1,13 @@
 "Test , coverage 17%."
 
 from idlelib import iomenu
+import os
 import unittest
+from unittest import mock
 from test.support import requires
-from tkinter import Tk
+from tkinter import Tk, TclVersion
 from idlelib.editor import EditorWindow
-from idlelib import util
+from idlelib import macosx, util
 from idlelib.idle_test.mock_idle import Func
 
 # Fail if either tokenize.open and t.detect_encoding does not exist.
@@ -38,6 +40,17 @@ def tearDownClass(cls):
     def test_init(self):
         self.assertIs(self.io.editwin, self.editwin)
 
+    def test_defaultfilename_tilde(self):
+        # gh-59568: escape a leading tilde for Tcl older than 9.
+        io = self.io
+        with mock.patch.object(io, 'filename', os.path.join('dir', '~file.py')):
+            dirname, base = io.defaultfilename()
+        self.assertEqual(dirname, 'dir')
+        if TclVersion < 9 and not macosx.isAquaTk():
+            self.assertEqual(base, os.path.join(os.curdir, '~file.py'))
+        else:
+            self.assertEqual(base, '~file.py')
+
     def test_fixnewlines_end(self):
         eq = self.assertEqual
         io = self.io
diff --git a/Lib/idlelib/idle_test/test_query.py b/Lib/idlelib/idle_test/test_query.py
index 58c173723a5adac..3b0a3388f64e330 100644
--- a/Lib/idlelib/idle_test/test_query.py
+++ b/Lib/idlelib/idle_test/test_query.py
@@ -280,11 +280,20 @@ def test_blank_args(self):
         dialog = self.Dummy_CustomRun(' ')
         self.assertEqual(dialog.cli_args_ok(), [])
 
+    @unittest.skipIf(sys.platform == 'win32', 'not an error on Windows')
     def test_invalid_args(self):
         dialog = self.Dummy_CustomRun("'no-closing-quote")
         self.assertEqual(dialog.cli_args_ok(), None)
         self.assertIn('No closing', dialog.entry_error['text'])
 
+    @unittest.skipUnless(sys.platform == 'win32', 'Windows only')
+    def test_windows_args(self):
+        # gh-93016: backslashes are not escapes on Windows.
+        dialog = self.Dummy_CustomRun(r'c:\Users "c:\Program Files"')
+        self.assertEqual(dialog.cli_args_ok(),
+                         [r'c:\Users', r'c:\Program Files'])
+        self.assertEqual(dialog.entry_error['text'], '')
+
     def test_good_args(self):
         args = ['-n', '10', '--verbose', '-p', '/path', '--name']
         dialog = self.Dummy_CustomRun(' '.join(args) + ' "my name"')
@@ -444,6 +453,12 @@ def test_click_args(self):
         dialog.entry.insert(END, ' c')
         dialog.button_ok.invoke()
         self.assertEqual(dialog.result, (['a', 'b=1', 'c'], True))
+        # gh-93016: arguments with spaces and backslashes round-trip.
+        args = ['a b', r'c:\dir\x']
+        dialog =  query.CustomRun(root, 'Title', cli_args=args, _utest=True)
+        self.assertNotIn('{', dialog.entry.get())
+        dialog.button_ok.invoke()
+        self.assertEqual(dialog.result, (args, True))
         root.destroy()
 
 
diff --git a/Lib/idlelib/idle_test/test_util.py b/Lib/idlelib/idle_test/test_util.py
index d90a0784075d3e0..adf871fe4399cb3 100644
--- a/Lib/idlelib/idle_test/test_util.py
+++ b/Lib/idlelib/idle_test/test_util.py
@@ -3,7 +3,7 @@
 import sys
 import unittest
 from unittest import mock
-from test.support import requires
+from test.support import requires, subTests
 from test.support.isolation import runInSubprocess
 import tkinter
 from tkinter import EventType
@@ -162,5 +162,38 @@ def test_fix_x11_paste(self):
                     self.assertEqual(after, before[cls])
 
 
+class CLIargsTest(unittest.TestCase):
+    "Test the command line splitting and joining functions (gh-93016)."
+
+    # Expected results were verified against sys.argv of python.exe.
+    @subTests('cli_string,args', [
+        (r'c:\Users', [r'c:\Users']),
+        (r'\\server\share', [r'\\server\share']),
+        (r'"c:\Program Files\x" 1 2', [r'c:\Program Files\x', '1', '2']),
+        (r'  x  y ', ['x', 'y']),
+        ('a\tb', ['a', 'b']),
+        (r'"a b"c', ['a bc']),
+        (r'a"b c"d', ['ab cd']),
+        (r'"a""b"', ['a"b']),
+        (r'a\"b', ['a"b']),
+        (r'a\\"b c" d', ['a\\b c', 'd']),
+        (r'a\\\"b', ['a\\"b']),
+        (r'"x\\"', ['x\\']),
+        ('"c:\\Users\\"', ['c:\\Users"']),
+        ('x\\', ['x\\']),
+        (r'""', ['']),
+        (r'"" a', ['', 'a']),
+        (r'"', ['']),
+        ('', []),
+    ])
+    def test_split_windows(self, cli_string, args):
+        self.assertEqual(util._split_windows(cli_string), args)
+
+    @subTests('args', [['a'], ['a b'], [r'c:\x'], ['q"q'], ["s's"], [''],
+                       ['\\'], ['\\"'], ['a b', r'c:\x', '', 'q"q']])
+    def test_split_join(self, args):
+        self.assertEqual(util.split_cli_args(util.join_cli_args(args)), args)
+
+
 if __name__ == '__main__':
     unittest.main(verbosity=2)
diff --git a/Lib/idlelib/iomenu.py b/Lib/idlelib/iomenu.py
index 9560aaa2da0c424..96bf6078f12c3ec 100644
--- a/Lib/idlelib/iomenu.py
+++ b/Lib/idlelib/iomenu.py
@@ -5,11 +5,13 @@
 import tempfile
 import tokenize
 
+from tkinter import TclVersion
 from tkinter import filedialog
 from tkinter import messagebox
 from tkinter.simpledialog import askstring  # loadfile encoding.
 
 from idlelib.config import idleConf
+from idlelib import macosx
 from idlelib.util import py_extensions
 
 py_extensions = ' '.join("*"+ext for ext in py_extensions)
@@ -405,7 +407,12 @@ def askopenfile(self):
 
     def defaultfilename(self, mode="open"):
         if self.filename:
-            return os.path.split(self.filename)
+            dirname, base = os.path.split(self.filename)
+            if base[:1] == '~' and TclVersion < 9 and not macosx.isAquaTk():
+                # Tcl before version 9 substitutes a leading tilde in
+                # a file name (gh-59568).  The macOS dialog does not.
+                base = os.path.join(os.curdir, base)
+            return dirname, base
         elif self.dirname:
             return self.dirname, ""
         else:
diff --git a/Lib/idlelib/pyshell.py b/Lib/idlelib/pyshell.py
index 19a6569ac61182e..1aeabba0a728feb 100755
--- a/Lib/idlelib/pyshell.py
+++ b/Lib/idlelib/pyshell.py
@@ -705,6 +705,8 @@ def execfile(self, filename, source=None):
 
     def runsource(self, source):
         "Extend base class method: Stuff the source in the line cache first"
+        # Remove the highlighting of a previous syntax error (gh-93966).
+        self.tkconsole.text.tag_remove("ERROR", "1.0", "end")
         filename = self.stuffsource(source)
         # at the moment, InteractiveInterpreter expects str
         assert isinstance(source, str)
@@ -741,7 +743,6 @@ def showsyntaxerror(self, filename=None, **kwargs):
         """
         tkconsole = self.tkconsole
         text = tkconsole.text
-        text.tag_remove("ERROR", "1.0", "end")
         type, value, tb = sys.exc_info()
         if not issubclass(type, SyntaxError):
             tkconsole.resetoutput()
diff --git a/Lib/idlelib/query.py b/Lib/idlelib/query.py
index 5f9bdc031e544b7..6217b8123de76d4 100644
--- a/Lib/idlelib/query.py
+++ b/Lib/idlelib/query.py
@@ -21,7 +21,6 @@
 
 import importlib.util, importlib.abc
 import os
-import shlex
 from sys import executable, platform  # Platform is set for one test.
 
 from tkinter import Toplevel, StringVar, BooleanVar, W, E, S
@@ -30,6 +29,8 @@
 from tkinter.font import Font
 from tkinter.simpledialog import _setup_dialog
 
+from idlelib.util import split_cli_args, join_cli_args
+
 class Query(Toplevel):
     """Base class for getting verified answer from a user.
 
@@ -332,6 +333,7 @@ def entry_ok(self):
         path = self.path_ok()
         return None if name is None or path is None else (name, path)
 
+
 class CustomRun(Query):
     """Get settings for custom run of module.
 
@@ -344,12 +346,11 @@ def __init__(self, parent, title, *, cli_args=[],
                  _htest=False, _utest=False):
         """cli_args is a list of strings.
 
-        The list is assigned to the default Entry StringVar.
-        The strings are displayed joined by ' ' for display.
+        The strings are quoted and joined for display in the Entry.
         """
         message = 'Command Line Arguments for sys.argv:'
         super().__init__(
-                parent, title, message, text0=cli_args,
+                parent, title, message, text0=join_cli_args(cli_args),
                 _htest=_htest, _utest=_utest)
 
     def create_extra(self):
@@ -369,7 +370,7 @@ def cli_args_ok(self):
         "Return command line arg list or None if error."
         cli_string = self.entry.get().strip()
         try:
-            cli_args = shlex.split(cli_string, posix=True)
+            cli_args = split_cli_args(cli_string)
         except ValueError as err:
             self.showerror(str(err))
             return None
diff --git a/Lib/idlelib/util.py b/Lib/idlelib/util.py
index f408daf728d4a97..68391d5eef2b9f8 100644
--- a/Lib/idlelib/util.py
+++ b/Lib/idlelib/util.py
@@ -12,6 +12,7 @@
     * std streams (pyshell, run),
     * warning stuff (pyshell, run).
 """
+import re
 import sys
 
 # .pyw is for Windows; .pyi is for typing stub files.
@@ -114,6 +115,60 @@ def wheel_event(event, widget=None):
     return 'break'
 
 
+_cli_token_re = re.compile(r"""
+    (?P<backslashes>\\*)(?P<quotes>"+)
+  | (?P<literal>\\+|[^ \t"\\]+)  # backslashes not followed by a quote
+  | (?P<space>[ \t]+)
+""", re.VERBOSE)
+
+
+def _split_windows(cli_string):
+    """Split a command line into arguments as the C runtime does.
+
+    See https://learn.microsoft.com/cpp/c-language/parsing-c-command-line-arguments
+    """
+    args = []
+    arg = None  # None when not in an argument.
+    quoted = False
+    for m in _cli_token_re.finditer(cli_string):
+        match m.lastgroup:
+            case 'space' if not quoted:
+                if arg is not None:
+                    args.append(arg)
+                    arg = None
+            case 'space' | 'literal':
+                arg = (arg or '') + m[0]
+            case _:  # Backslashes followed by quotes.
+                count = len(m['backslashes'])
+                escaped = count % 2  # Odd backslashes escape a quote.
+                bare = len(m['quotes']) - escaped
+                # In a quoted part every two quotes give a literal quote;
+                # if not quoted, the first quote opens a quoted part.
+                literal = escaped + ((bare + quoted - 1) // 2 if bare else 0)
+                arg = (arg or '') + '\\' * (count // 2) + '"' * literal
+                quoted ^= bare % 2
+    if arg is not None:
+        args.append(arg)
+    return args
+
+
+def split_cli_args(cli_string):  # Called in query.
+    "Split a command line as the Python executable does (gh-93016)."
+    if sys.platform == 'win32':
+        return _split_windows(cli_string)
+    import shlex
+    return shlex.split(cli_string)
+
+
+def join_cli_args(cli_args):  # Called in query.
+    "Join arguments into a command line which split_cli_args() splits back."
+    if sys.platform == 'win32':
+        import subprocess
+        return subprocess.list2cmdline(cli_args)
+    import shlex
+    return shlex.join(cli_args)
+
+
 if __name__ == '__main__':
     from unittest import main
     main('idlelib.idle_test.test_util', verbosity=2)
diff --git a/Lib/test/test_fstring.py b/Lib/test/test_fstring.py
index 2fe959f6c14f77a..63006266bcd039e 100644
--- a/Lib/test/test_fstring.py
+++ b/Lib/test/test_fstring.py
@@ -617,6 +617,34 @@ def test_unterminated_string(self):
                              r"""f'{("x}'""",
                              ])
 
+    def test_unclosed_multiline_replacement_field(self):
+        for prefix in ('f', 't', 'rf', 'rt'):
+            for quote in ('"', "'"):
+                triple = quote * 3
+                cases = (
+                    # The apparent closing quotes open a string in the field.
+                    ('var = "abc"\na = PREFIXQUOTE {var} extern "C" { QUOTE\n'
+                     'b = QUOTE string QUOTE', 2),
+                    # Parentheses and dictionaries inside the field must not
+                    # change which opening brace the diagnostic identifies.
+                    ('a = PREFIXQUOTE{\n(QUOTE', 1),
+                    ('a = PREFIXQUOTE{\n{0: QUOTE', 1),
+                    # Use the innermost format field or formatted string.
+                    ('a = PREFIXQUOTE{0:\n{1\nQUOTE', 2),
+                    ('a = f"{\nPREFIXQUOTE{1\nQUOTE', 2),
+                    # Account for parentheses outside the formatted string.
+                    ('a = (PREFIXQUOTE{1\nQUOTE', 1),
+                )
+                for source, lineno in cases:
+                    source = source.replace('PREFIX', prefix).replace('QUOTE', triple)
+                    with self.subTest(source=source):
+                        with self.assertRaises(SyntaxError) as cm:
+                            compile(source, '<test>', 'exec')
+                        self.assertEqual(
+                            cm.exception.msg,
+                            f"{prefix[-1]}-string: expecting '}}' to close '{{' "
+                            f"on line {lineno}")
+
     @unittest.skipIf(support.is_wasi, "exhausts limited stack on WASI")
     def test_mismatched_parens(self):
         self.assertAllRaise(SyntaxError, r"closing parenthesis '\}' "
diff --git a/Lib/test/test_unparse.py b/Lib/test/test_unparse.py
index 28faede2e2a1a5c..9bc04fc8e0affb9 100644
--- a/Lib/test/test_unparse.py
+++ b/Lib/test/test_unparse.py
@@ -693,6 +693,24 @@ def test_unparse_interactive_integrity_3(self):
 
             self.check_src_roundtrip(src, out, mode='single')
 
+    @test.support.subTests('case', [
+        "case 'a string':",
+        "case True:",
+        "case _:",
+        "case [*_]:",
+        "case tuple():",
+        "case cls(arg, more=arg2):",
+        "case tuple() | list():",
+        "case [tuple() as obj, _, {'a': a, **more}]:",
+        "case -2:",
+        "case +2:",
+        "case 2 + 3j:",
+        "case +2 - 3j:",
+    ])
+    def test_unparse_match(self, case):
+        src = 'match x:\n    ' + case + '\n        pass'
+        self.check_src_roundtrip(src)
+
 
 class CosmeticTestCase(ASTTestCase):
     """Test if there are cosmetic issues caused by unnecessary additions"""
diff --git a/Misc/NEWS.d/next/Core_and_Builtins/2026-06-30-14-50-00.gh-issue-152708.aBcDeF.rst b/Misc/NEWS.d/next/Core_and_Builtins/2026-06-30-14-50-00.gh-issue-152708.aBcDeF.rst
new file mode 100644
index 000000000000000..edcf99f56ff9071
--- /dev/null
+++ b/Misc/NEWS.d/next/Core_and_Builtins/2026-06-30-14-50-00.gh-issue-152708.aBcDeF.rst
@@ -0,0 +1 @@
+Fix AST generation asymmetry where unary positive ``+`` was implicitly dropped in pattern match expressions, restoring parsing parity with unary negative ``-``.
diff --git a/Misc/NEWS.d/next/Core_and_Builtins/2026-09-19-12-00-00.gh-issue-157778.fstring-brace.rst b/Misc/NEWS.d/next/Core_and_Builtins/2026-09-19-12-00-00.gh-issue-157778.fstring-brace.rst
new file mode 100644
index 000000000000000..cb1bc8942d1b1b4
--- /dev/null
+++ b/Misc/NEWS.d/next/Core_and_Builtins/2026-09-19-12-00-00.gh-issue-157778.fstring-brace.rst
@@ -0,0 +1,3 @@
+Include the line number of the opening brace in the :exc:`SyntaxError` for
+an unclosed f-string or t-string replacement field when a matching quote
+on a later line is interpreted as the start of an unterminated string.
diff --git a/Misc/NEWS.d/next/IDLE/2026-09-15-22-10-17.gh-issue-93966.ch4fTB.rst b/Misc/NEWS.d/next/IDLE/2026-09-15-22-10-17.gh-issue-93966.ch4fTB.rst
new file mode 100644
index 000000000000000..3260b42211b780b
--- /dev/null
+++ b/Misc/NEWS.d/next/IDLE/2026-09-15-22-10-17.gh-issue-93966.ch4fTB.rst
@@ -0,0 +1,2 @@
+The highlighting of a syntax error in the IDLE Shell is now removed when the
+next statement is entered, not only when the next syntax error occurs.
diff --git a/Misc/NEWS.d/next/IDLE/2026-09-16-18-00-00.gh-issue-59568.tilde1.rst b/Misc/NEWS.d/next/IDLE/2026-09-16-18-00-00.gh-issue-59568.tilde1.rst
new file mode 100644
index 000000000000000..3eabd4e176ad8a6
--- /dev/null
+++ b/Misc/NEWS.d/next/IDLE/2026-09-16-18-00-00.gh-issue-59568.tilde1.rst
@@ -0,0 +1,2 @@
+Fix "Save As" and "Open" dialogs in IDLE for a file whose name starts with
+``~`` on Windows and X11 with Tcl/Tk older than 9.
diff --git a/Misc/NEWS.d/next/IDLE/2026-09-16-20-00-00.gh-issue-93016.cliarg.rst b/Misc/NEWS.d/next/IDLE/2026-09-16-20-00-00.gh-issue-93016.cliarg.rst
new file mode 100644
index 000000000000000..a9fe00a72fe87c3
--- /dev/null
+++ b/Misc/NEWS.d/next/IDLE/2026-09-16-20-00-00.gh-issue-93016.cliarg.rst
@@ -0,0 +1,3 @@
+Fix parsing of command line arguments in the IDLE "Run... Customized" dialog
+on Windows: backslashes are no longer treated as escape characters. Fix also
+display of the previous arguments in the dialog.
diff --git a/Parser/lexer/string.c b/Parser/lexer/string.c
index 945480ef86f7789..1fb684e337de972 100644
--- a/Parser/lexer/string.c
+++ b/Parser/lexer/string.c
@@ -355,9 +355,19 @@ _PyLexer_scan_string(struct tok_state *tok, struct token *token, int c)
 
             const ftstring_state *state = _PyLexer_CurrentFTString(tok);
             if (state != NULL) {
-                /* A matching quote belongs to the surrounding formatted
-                 * string, so the expression is missing its closing brace. */
+                /* A matching quote may have been intended to close the
+                 * surrounding formatted string instead of opening a string
+                 * inside a replacement field. */
                 if (state->quote == quote && state->quote_size == quote_size) {
+                    int level = state->paren_level + state->replacement_depth - 1;
+                    assert(level >= 0 && level < tok->level);
+                    assert(tok->parenstack[level] == '{');
+                    int lineno = tok->parenlinenostack[level];
+                    if (lineno != tok->lineno) {
+                        return MAKE_TOKEN(_PyTokenizer_syntaxerror(tok,
+                            "%c-string: expecting '}' to close '{' on line %d",
+                            _PyLexer_StringPrefix(state->kind), lineno));
+                    }
                     return MAKE_TOKEN(_PyTokenizer_syntaxerror(tok,
                         "%c-string: expecting '}'",
                         _PyLexer_StringPrefix(state->kind)));
diff --git a/Parser/parser.c b/Parser/parser.c
index bb8a43caf9bd353..b3d73dd4fafb762 100644
--- a/Parser/parser.c
+++ b/Parser/parser.c
@@ -9116,7 +9116,16 @@ signed_number_rule(Parser *p)
         )
         {
             D(fprintf(stderr, "%*c+ signed_number[%d-%d]: %s succeeded!\n", p->level, ' ', _mark, p->mark, "'+' NUMBER"));
-            _res = number;
+            Token *_token = _PyPegen_get_last_nonnwhitespace_token(p);
+            if (_token == NULL) {
+                p->level--;
+                return NULL;
+            }
+            int _end_lineno = _token->end_lineno;
+            UNUSED(_end_lineno); // Only used by EXTRA macro
+            int _end_col_offset = _token->end_col_offset;
+            UNUSED(_end_col_offset); // Only used by EXTRA macro
+            _res = _PyAST_UnaryOp ( UAdd , number , EXTRA );
             if ((_res == NULL || p->error_indicator) && PyErr_Occurred()) {
                 p->error_indicator = 1;
                 p->level--;
@@ -9226,7 +9235,16 @@ signed_real_number_rule(Parser *p)
         )
         {
             D(fprintf(stderr, "%*c+ signed_real_number[%d-%d]: %s succeeded!\n", p->level, ' ', _mark, p->mark, "'+' real_number"));
-            _res = real;
+            Token *_token = _PyPegen_get_last_nonnwhitespace_token(p);
+            if (_token == NULL) {
+                p->level--;
+                return NULL;
+            }
+            int _end_lineno = _token->end_lineno;
+            UNUSED(_end_lineno); // Only used by EXTRA macro
+            int _end_col_offset = _token->end_col_offset;
+            UNUSED(_end_col_offset); // Only used by EXTRA macro
+            _res = _PyAST_UnaryOp ( UAdd , real , EXTRA );
             if ((_res == NULL || p->error_indicator) && PyErr_Occurred()) {
                 p->error_indicator = 1;
                 p->level--;
diff --git a/Python/ast.c b/Python/ast.c
index f625c59fe5bffc3..1befd1778114927 100644
--- a/Python/ast.c
+++ b/Python/ast.c
@@ -426,11 +426,11 @@ ensure_literal_number(expr_ty exp, bool allow_real, bool allow_imaginary)
 }
 
 static int
-ensure_literal_negative(expr_ty exp, bool allow_real, bool allow_imaginary)
+ensure_literal_signed(expr_ty exp, bool allow_real, bool allow_imaginary)
 {
     assert(exp->kind == UnaryOp_kind);
-    // Must be negation ...
-    if (exp->v.UnaryOp.op != USub) {
+    // Must be negation or positive ...
+    if (exp->v.UnaryOp.op != USub && exp->v.UnaryOp.op != UAdd) {
         return 0;
     }
     // ... of a constant ...
@@ -461,7 +461,7 @@ ensure_literal_complex(expr_ty exp)
             }
             break;
         case UnaryOp_kind:
-            if (!ensure_literal_negative(left, /*real=*/true, /*imaginary=*/false)) {
+            if (!ensure_literal_signed(left, /*real=*/true, /*imaginary=*/false)) {
                 return 0;
             }
             break;
@@ -512,9 +512,9 @@ validate_pattern_match_value(expr_ty exp)
             // Constants and attribute lookups are always permitted
             return 1;
         case UnaryOp_kind:
-            // Negated numbers are permitted (whether real or imaginary)
+            // Signed numbers are permitted (whether real or imaginary)
             // Compiler will complain if AST folding doesn't create a constant
-            if (ensure_literal_negative(exp, /*real=*/true, /*imaginary=*/true)) {
+            if (ensure_literal_signed(exp, /*real=*/true, /*imaginary=*/true)) {
                 return 1;
             }
             break;
diff --git a/Python/ast_preprocess.c b/Python/ast_preprocess.c
index 54dec3dfe042686..951b3f71522b254 100644
--- a/Python/ast_preprocess.c
+++ b/Python/ast_preprocess.c
@@ -867,11 +867,11 @@ fold_const_match_patterns(expr_ty node, PyArena *ctx_, _PyASTPreprocessState *st
     {
         case UnaryOp_kind:
         {
-            if (node->v.UnaryOp.op == USub &&
+            if ((node->v.UnaryOp.op == USub || node->v.UnaryOp.op == UAdd) &&
                 node->v.UnaryOp.operand->kind == Constant_kind)
             {
                 PyObject *operand = node->v.UnaryOp.operand->v.Constant.value;
-                PyObject *folded = PyNumber_Negative(operand);
+                PyObject *folded = node->v.UnaryOp.op == USub ? PyNumber_Negative(operand) : PyNumber_Positive(operand);
                 return make_const(node, folded, ctx_);
             }
             break;