From 05c961b808bfd8d2e87e569e5694694cfd35702b Mon Sep 17 00:00:00 2001
From: Anderson Bravalheri <andersonbravalheri@gmail.com>
Date: Wed, 23 Feb 2022 11:14:26 +0000
Subject: [PATCH 01/12] Don't warn on false positive for author/maintainer's
 email

While I was working to support pyproject.toml metadata in setuptools,
I received as a feedback from the community[^1] that setuptools
warns the following message when `author_email` and `maintainer_email`
are given in the form of `Person Name <email@address>`:

> warning: check: missing meta-data: either (author and author_email)
> or (maintainer and maintainer_email) should be supplied

This can be seen as a false positive, because indeed both author's name
and email are provided.

This warning seems to happen because distutils define the `check`
command as a subcommand for `sdist`.

This change aims to remove this false positive result from the checks.

[^1]: https://discuss.python.org/t/help-testing-experimental-features-in-setuptools/13821/18
---
 distutils/command/check.py    | 40 +++++++++++++++++++++++++++--------
 distutils/tests/test_check.py | 22 +++++++++++++++++++
 2 files changed, 53 insertions(+), 9 deletions(-)

diff --git a/distutils/command/check.py b/distutils/command/check.py
index 525540b6cc..af311ca90e 100644
--- a/distutils/command/check.py
+++ b/distutils/command/check.py
@@ -2,6 +2,8 @@
 
 Implements the Distutils 'check' command.
 """
+from email.utils import getaddresses
+
 from distutils.core import Command
 from distutils.errors import DistutilsSetupError
 
@@ -96,19 +98,39 @@ def check_metadata(self):
 
         if missing:
             self.warn("missing required meta-data: %s"  % ', '.join(missing))
-        if metadata.author:
-            if not metadata.author_email:
-                self.warn("missing meta-data: if 'author' supplied, " +
-                          "'author_email' should be supplied too")
-        elif metadata.maintainer:
-            if not metadata.maintainer_email:
-                self.warn("missing meta-data: if 'maintainer' supplied, " +
-                          "'maintainer_email' should be supplied too")
-        else:
+        if not (
+            self._check_contact("author", metadata) or
+            self._check_contact("maintainer", metadata)
+        ):
             self.warn("missing meta-data: either (author and author_email) " +
                       "or (maintainer and maintainer_email) " +
                       "should be supplied")
 
+    def _check_contact(self, kind, metadata):
+        """
+        Returns True if the contact's name is specified and False otherwise.
+        This function will warn if the contact's email is not specified.
+        """
+        name = getattr(metadata, kind) or ''
+        email = getattr(metadata, kind + '_email') or ''
+
+        msg = ("missing meta-data: if '{}' supplied, " +
+               "'{}' should be supplied too")
+
+        if name and email:
+            return True
+
+        if name:
+            self.warn(msg.format(kind, kind + '_email'))
+            return True
+
+        addresses = [(alias, addr) for alias, addr in getaddresses([email])]
+        if any(alias and addr for alias, addr in addresses):
+            # The contact's name can be encoded in the email: `Name <email>`
+            return True
+
+        return False
+
     def check_restructuredtext(self):
         """Checks if the long string fields are reST-compliant."""
         data = self.distribution.get_long_description()
diff --git a/distutils/tests/test_check.py b/distutils/tests/test_check.py
index 91bcdceb43..b41dba3d0a 100644
--- a/distutils/tests/test_check.py
+++ b/distutils/tests/test_check.py
@@ -71,6 +71,28 @@ def test_check_metadata(self):
         cmd = self._run(metadata)
         self.assertEqual(cmd._warnings, 0)
 
+    def test_check_author_maintainer(self):
+        for kind in ("author", "maintainer"):
+            # ensure no warning when author_email or maintainer_email is given
+            # (the spec allows these fields to take the form "Name <email>")
+            metadata = {'url': 'xxx',
+                        kind + '_email': 'Name <name@email.com>',
+                        'name': 'xxx', 'version': 'xxx'}
+            cmd = self._run(metadata)
+            self.assertEqual(cmd._warnings, 0)
+
+            # the check should warn if only email is given and it does not
+            # contain the name
+            metadata[kind + '_email'] = 'name@email.com'
+            cmd = self._run(metadata)
+            self.assertEqual(cmd._warnings, 1)
+
+            # the check should warn if only the name is given
+            metadata[kind] = "Name"
+            del metadata[kind + '_email']
+            cmd = self._run(metadata)
+            self.assertEqual(cmd._warnings, 1)
+
     @unittest.skipUnless(HAS_DOCUTILS, "won't test without docutils")
     def test_check_document(self):
         pkg_info, dist = self.create_dist()

From b16cf407dcbbfab0df079e894819ea5dce166b48 Mon Sep 17 00:00:00 2001
From: "Jason R. Coombs" <jaraco@jaraco.com>
Date: Sun, 27 Mar 2022 10:20:24 -0400
Subject: [PATCH 02/12] =?UTF-8?q?=F0=9F=91=B9=20Feed=20the=20hobgoblins=20?=
 =?UTF-8?q?(delint).?=
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit

---
 distutils/command/build_scripts.py | 11 ++++++-----
 1 file changed, 6 insertions(+), 5 deletions(-)

diff --git a/distutils/command/build_scripts.py b/distutils/command/build_scripts.py
index e3312cf0ca..dbeef2ddb0 100644
--- a/distutils/command/build_scripts.py
+++ b/distutils/command/build_scripts.py
@@ -2,7 +2,8 @@
 
 Implements the Distutils 'build_scripts' command."""
 
-import os, re
+import os
+import re
 from stat import ST_MODE
 from distutils import sysconfig
 from distutils.core import Command
@@ -14,6 +15,7 @@
 # check if Python is called on the first line with this expression
 first_line_re = re.compile(b'^#!.*python[0-9.]*([ \t].*)?$')
 
+
 class build_scripts(Command):
 
     description = "\"build\" scripts (copy and fixup #! line)"
@@ -26,7 +28,6 @@ class build_scripts(Command):
 
     boolean_options = ['force']
 
-
     def initialize_options(self):
         self.build_dir = None
         self.scripts = None
@@ -49,7 +50,6 @@ def run(self):
             return
         self.copy_scripts()
 
-
     def copy_scripts(self):
         r"""Copy each script listed in 'self.scripts'; if it's marked as a
         Python script in the Unix way (first line matches 'first_line_re',
@@ -101,8 +101,9 @@ def copy_scripts(self):
                     else:
                         executable = os.path.join(
                             sysconfig.get_config_var("BINDIR"),
-                           "python%s%s" % (sysconfig.get_config_var("VERSION"),
-                                           sysconfig.get_config_var("EXE")))
+                            "python%s%s" % (
+                                sysconfig.get_config_var("VERSION"),
+                                sysconfig.get_config_var("EXE")))
                     executable = os.fsencode(executable)
                     shebang = b"#!" + executable + post_interp + b"\n"
                     # Python parser starts to read a script using UTF-8 until

From 6736459f5bc024bd640ab564c7a5ee0b2d1c0416 Mon Sep 17 00:00:00 2001
From: "Jason R. Coombs" <jaraco@jaraco.com>
Date: Sun, 27 Mar 2022 10:28:33 -0400
Subject: [PATCH 03/12] Rewrite docstring for imperative voice and proper
 structure.

---
 distutils/command/build_scripts.py | 11 +++++++----
 1 file changed, 7 insertions(+), 4 deletions(-)

diff --git a/distutils/command/build_scripts.py b/distutils/command/build_scripts.py
index dbeef2ddb0..64a472aeba 100644
--- a/distutils/command/build_scripts.py
+++ b/distutils/command/build_scripts.py
@@ -51,10 +51,13 @@ def run(self):
         self.copy_scripts()
 
     def copy_scripts(self):
-        r"""Copy each script listed in 'self.scripts'; if it's marked as a
-        Python script in the Unix way (first line matches 'first_line_re',
-        ie. starts with "\#!" and contains "python"), then adjust the first
-        line to refer to the current Python interpreter as we copy.
+        """
+        Copy each script listed in ``self.scripts``.
+
+        If a script is marked as a Python script (first line matches
+        'first_line_re', i.e. starts with ``#!`` and contains
+        "python"), then adjust in the copy the first line to refer to
+        the current Python interpreter.
         """
         self.mkpath(self.build_dir)
         outfiles = []

From beefbe746fd875ea75f6943f55ccca3b77b44674 Mon Sep 17 00:00:00 2001
From: "Jason R. Coombs" <jaraco@jaraco.com>
Date: Sun, 27 Mar 2022 10:31:08 -0400
Subject: [PATCH 04/12] Move 'updated_files' operation outside of if statement
 as it appears in both branches unconditionally.

---
 distutils/command/build_scripts.py | 3 +--
 1 file changed, 1 insertion(+), 2 deletions(-)

diff --git a/distutils/command/build_scripts.py b/distutils/command/build_scripts.py
index 64a472aeba..cee65c6430 100644
--- a/distutils/command/build_scripts.py
+++ b/distutils/command/build_scripts.py
@@ -94,10 +94,10 @@ def copy_scripts(self):
                     adjust = True
                     post_interp = match.group(1) or b''
 
+            updated_files.append(outfile)
             if adjust:
                 log.info("copying and adjusting %s -> %s", script,
                          self.build_dir)
-                updated_files.append(outfile)
                 if not self.dry_run:
                     if not sysconfig.python_build:
                         executable = self.executable
@@ -138,7 +138,6 @@ def copy_scripts(self):
             else:
                 if f:
                     f.close()
-                updated_files.append(outfile)
                 self.copy_file(script, outfile)
 
         if os.name == 'posix':

From fe5e02dd434e98137189406a710c8fa2bfa42e5c Mon Sep 17 00:00:00 2001
From: "Jason R. Coombs" <jaraco@jaraco.com>
Date: Sun, 27 Mar 2022 10:44:25 -0400
Subject: [PATCH 05/12] Extract method for copying a file.

---
 distutils/command/build_scripts.py | 155 +++++++++++++++--------------
 1 file changed, 79 insertions(+), 76 deletions(-)

diff --git a/distutils/command/build_scripts.py b/distutils/command/build_scripts.py
index cee65c6430..359b476501 100644
--- a/distutils/command/build_scripts.py
+++ b/distutils/command/build_scripts.py
@@ -63,82 +63,7 @@ def copy_scripts(self):
         outfiles = []
         updated_files = []
         for script in self.scripts:
-            adjust = False
-            script = convert_path(script)
-            outfile = os.path.join(self.build_dir, os.path.basename(script))
-            outfiles.append(outfile)
-
-            if not self.force and not newer(script, outfile):
-                log.debug("not copying %s (up-to-date)", script)
-                continue
-
-            # Always open the file, but ignore failures in dry-run mode --
-            # that way, we'll get accurate feedback if we can read the
-            # script.
-            try:
-                f = open(script, "rb")
-            except OSError:
-                if not self.dry_run:
-                    raise
-                f = None
-            else:
-                encoding, lines = tokenize.detect_encoding(f.readline)
-                f.seek(0)
-                first_line = f.readline()
-                if not first_line:
-                    self.warn("%s is an empty file (skipping)" % script)
-                    continue
-
-                match = first_line_re.match(first_line)
-                if match:
-                    adjust = True
-                    post_interp = match.group(1) or b''
-
-            updated_files.append(outfile)
-            if adjust:
-                log.info("copying and adjusting %s -> %s", script,
-                         self.build_dir)
-                if not self.dry_run:
-                    if not sysconfig.python_build:
-                        executable = self.executable
-                    else:
-                        executable = os.path.join(
-                            sysconfig.get_config_var("BINDIR"),
-                            "python%s%s" % (
-                                sysconfig.get_config_var("VERSION"),
-                                sysconfig.get_config_var("EXE")))
-                    executable = os.fsencode(executable)
-                    shebang = b"#!" + executable + post_interp + b"\n"
-                    # Python parser starts to read a script using UTF-8 until
-                    # it gets a #coding:xxx cookie. The shebang has to be the
-                    # first line of a file, the #coding:xxx cookie cannot be
-                    # written before. So the shebang has to be decodable from
-                    # UTF-8.
-                    try:
-                        shebang.decode('utf-8')
-                    except UnicodeDecodeError:
-                        raise ValueError(
-                            "The shebang ({!r}) is not decodable "
-                            "from utf-8".format(shebang))
-                    # If the script is encoded to a custom encoding (use a
-                    # #coding:xxx cookie), the shebang has to be decodable from
-                    # the script encoding too.
-                    try:
-                        shebang.decode(encoding)
-                    except UnicodeDecodeError:
-                        raise ValueError(
-                            "The shebang ({!r}) is not decodable "
-                            "from the script encoding ({})"
-                            .format(shebang, encoding))
-                    with open(outfile, "wb") as outf:
-                        outf.write(shebang)
-                        outf.writelines(f.readlines())
-                if f:
-                    f.close()
-            else:
-                if f:
-                    f.close()
-                self.copy_file(script, outfile)
+            self._copy_script(script, outfiles, updated_files)
 
         if os.name == 'posix':
             for file in outfiles:
@@ -153,3 +78,81 @@ def copy_scripts(self):
                         os.chmod(file, newmode)
         # XXX should we modify self.outfiles?
         return outfiles, updated_files
+
+    def _copy_script(self, script, outfiles, updated_files):
+        adjust = False
+        script = convert_path(script)
+        outfile = os.path.join(self.build_dir, os.path.basename(script))
+        outfiles.append(outfile)
+
+        if not self.force and not newer(script, outfile):
+            log.debug("not copying %s (up-to-date)", script)
+            return
+
+        # Always open the file, but ignore failures in dry-run mode --
+        # that way, we'll get accurate feedback if we can read the
+        # script.
+        try:
+            f = open(script, "rb")
+        except OSError:
+            if not self.dry_run:
+                raise
+            f = None
+        else:
+            encoding, lines = tokenize.detect_encoding(f.readline)
+            f.seek(0)
+            first_line = f.readline()
+            if not first_line:
+                self.warn("%s is an empty file (skipping)" % script)
+                return
+
+            match = first_line_re.match(first_line)
+            if match:
+                adjust = True
+                post_interp = match.group(1) or b''
+
+        updated_files.append(outfile)
+        if adjust:
+            log.info("copying and adjusting %s -> %s", script,
+                     self.build_dir)
+            if not self.dry_run:
+                if not sysconfig.python_build:
+                    executable = self.executable
+                else:
+                    executable = os.path.join(
+                        sysconfig.get_config_var("BINDIR"),
+                        "python%s%s" % (
+                            sysconfig.get_config_var("VERSION"),
+                            sysconfig.get_config_var("EXE")))
+                executable = os.fsencode(executable)
+                shebang = b"#!" + executable + post_interp + b"\n"
+                # Python parser starts to read a script using UTF-8 until
+                # it gets a #coding:xxx cookie. The shebang has to be the
+                # first line of a file, the #coding:xxx cookie cannot be
+                # written before. So the shebang has to be decodable from
+                # UTF-8.
+                try:
+                    shebang.decode('utf-8')
+                except UnicodeDecodeError:
+                    raise ValueError(
+                        "The shebang ({!r}) is not decodable "
+                        "from utf-8".format(shebang))
+                # If the script is encoded to a custom encoding (use a
+                # #coding:xxx cookie), the shebang has to be decodable from
+                # the script encoding too.
+                try:
+                    shebang.decode(encoding)
+                except UnicodeDecodeError:
+                    raise ValueError(
+                        "The shebang ({!r}) is not decodable "
+                        "from the script encoding ({})"
+                        .format(shebang, encoding))
+                with open(outfile, "wb") as outf:
+                    outf.write(shebang)
+                    outf.writelines(f.readlines())
+            if f:
+                f.close()
+        else:
+            if f:
+                f.close()
+            self.copy_file(script, outfile)

From d80e72007a0397efe2026173a93a50106145304d Mon Sep 17 00:00:00 2001
From: "Jason R. Coombs" <jaraco@jaraco.com>
Date: Sun, 27 Mar 2022 10:50:49 -0400
Subject: [PATCH 06/12] Remove outfiles, unused.

---
 distutils/command/build_scripts.py | 3 +--
 1 file changed, 1 insertion(+), 2 deletions(-)

diff --git a/distutils/command/build_scripts.py b/distutils/command/build_scripts.py
index 359b476501..d717f3004d 100644
--- a/distutils/command/build_scripts.py
+++ b/distutils/command/build_scripts.py
@@ -33,7 +33,6 @@ def initialize_options(self):
         self.scripts = None
         self.force = None
         self.executable = None
-        self.outfiles = None
 
     def finalize_options(self):
         self.set_undefined_options('build',
@@ -76,7 +75,7 @@ def copy_scripts(self):
                         log.info("changing mode of %s from %o to %o",
                                  file, oldmode, newmode)
                         os.chmod(file, newmode)
-        # XXX should we modify self.outfiles?
+
         return outfiles, updated_files
 
     def _copy_script(self, script, outfiles, updated_files):

From f91759e6b7e11af9ee23a28a324e8a67ffe897b2 Mon Sep 17 00:00:00 2001
From: "Jason R. Coombs" <jaraco@jaraco.com>
Date: Sun, 27 Mar 2022 11:01:09 -0400
Subject: [PATCH 07/12] Extract _change_modes and _change_mode functions.

---
 distutils/command/build_scripts.py | 31 +++++++++++++++++++-----------
 1 file changed, 20 insertions(+), 11 deletions(-)

diff --git a/distutils/command/build_scripts.py b/distutils/command/build_scripts.py
index d717f3004d..07408efa60 100644
--- a/distutils/command/build_scripts.py
+++ b/distutils/command/build_scripts.py
@@ -64,17 +64,7 @@ def copy_scripts(self):
         for script in self.scripts:
             self._copy_script(script, outfiles, updated_files)
 
-        if os.name == 'posix':
-            for file in outfiles:
-                if self.dry_run:
-                    log.info("changing mode of %s", file)
-                else:
-                    oldmode = os.stat(file)[ST_MODE] & 0o7777
-                    newmode = (oldmode | 0o555) & 0o7777
-                    if newmode != oldmode:
-                        log.info("changing mode of %s from %o to %o",
-                                 file, oldmode, newmode)
-                        os.chmod(file, newmode)
+        self._change_modes(outfiles)
 
         return outfiles, updated_files
 
@@ -155,3 +145,22 @@ def _copy_script(self, script, outfiles, updated_files):
             if f:
                 f.close()
             self.copy_file(script, outfile)
+
+    def _change_modes(self, outfiles):
+        if os.name != 'posix':
+            return
+
+        for file in outfiles:
+            self._change_mode(file)
+
+    def _change_mode(self, file):
+        if self.dry_run:
+            log.info("changing mode of %s", file)
+            return
+
+        oldmode = os.stat(file)[ST_MODE] & 0o7777
+        newmode = (oldmode | 0o555) & 0o7777
+        if newmode != oldmode:
+            log.info("changing mode of %s from %o to %o",
+                     file, oldmode, newmode)
+            os.chmod(file, newmode)

From afaf3c099d745799ef6bc014f30ea417401e3baa Mon Sep 17 00:00:00 2001
From: "Jason R. Coombs" <jaraco@jaraco.com>
Date: Sun, 27 Mar 2022 11:11:20 -0400
Subject: [PATCH 08/12] Rewrite the comment to match the implementation.

---
 distutils/command/build_scripts.py | 5 ++---
 1 file changed, 2 insertions(+), 3 deletions(-)

diff --git a/distutils/command/build_scripts.py b/distutils/command/build_scripts.py
index 07408efa60..36047dccc6 100644
--- a/distutils/command/build_scripts.py
+++ b/distutils/command/build_scripts.py
@@ -78,9 +78,8 @@ def _copy_script(self, script, outfiles, updated_files):
             log.debug("not copying %s (up-to-date)", script)
             return
 
-        # Always open the file, but ignore failures in dry-run mode --
-        # that way, we'll get accurate feedback if we can read the
-        # script.
+        # Always open the file, but ignore failures in dry-run mode
+        # in order to attempt to copy directly.
         try:
             f = open(script, "rb")
         except OSError:

From 6a7d01c0d0b1960b343db5bc120d668a9f58ce84 Mon Sep 17 00:00:00 2001
From: "Jason R. Coombs" <jaraco@jaraco.com>
Date: Sun, 27 Mar 2022 11:17:14 -0400
Subject: [PATCH 09/12] Use 'shebang_' for pattern and match.

---
 distutils/command/build_scripts.py | 14 ++++++--------
 1 file changed, 6 insertions(+), 8 deletions(-)

diff --git a/distutils/command/build_scripts.py b/distutils/command/build_scripts.py
index 36047dccc6..d141a8804f 100644
--- a/distutils/command/build_scripts.py
+++ b/distutils/command/build_scripts.py
@@ -13,7 +13,7 @@
 import tokenize
 
 # check if Python is called on the first line with this expression
-first_line_re = re.compile(b'^#!.*python[0-9.]*([ \t].*)?$')
+shebang_pattern = re.compile(b'^#!.*python[0-9.]*([ \t].*)?$')
 
 
 class build_scripts(Command):
@@ -54,7 +54,7 @@ def copy_scripts(self):
         Copy each script listed in ``self.scripts``.
 
         If a script is marked as a Python script (first line matches
-        'first_line_re', i.e. starts with ``#!`` and contains
+        'shebang_pattern', i.e. starts with ``#!`` and contains
         "python"), then adjust in the copy the first line to refer to
         the current Python interpreter.
         """
@@ -69,7 +69,7 @@ def copy_scripts(self):
         return outfiles, updated_files
 
     def _copy_script(self, script, outfiles, updated_files):
-        adjust = False
+        shebang_match = None
         script = convert_path(script)
         outfile = os.path.join(self.build_dir, os.path.basename(script))
         outfiles.append(outfile)
@@ -94,13 +94,10 @@ def _copy_script(self, script, outfiles, updated_files):
                 self.warn("%s is an empty file (skipping)" % script)
                 return
 
-            match = first_line_re.match(first_line)
-            if match:
-                adjust = True
-                post_interp = match.group(1) or b''
+            shebang_match = shebang_pattern.match(first_line)
 
         updated_files.append(outfile)
-        if adjust:
+        if shebang_match:
             log.info("copying and adjusting %s -> %s", script,
                      self.build_dir)
             if not self.dry_run:
@@ -113,6 +110,7 @@ def _copy_script(self, script, outfiles, updated_files):
                             sysconfig.get_config_var("VERSION"),
                             sysconfig.get_config_var("EXE")))
                 executable = os.fsencode(executable)
+                post_interp = shebang_match.group(1) or b''
                 shebang = b"#!" + executable + post_interp + b"\n"
                 # Python parser starts to read a script using UTF-8 until
                 # it gets a #coding:xxx cookie. The shebang has to be the

From 12edb8d575966b50afe6b2f89383bf804e99b310 Mon Sep 17 00:00:00 2001
From: "Jason R. Coombs" <jaraco@jaraco.com>
Date: Sun, 27 Mar 2022 11:33:14 -0400
Subject: [PATCH 10/12] Extract method to validate the shebang.

---
 distutils/command/build_scripts.py | 47 +++++++++++++++++-------------
 1 file changed, 26 insertions(+), 21 deletions(-)

diff --git a/distutils/command/build_scripts.py b/distutils/command/build_scripts.py
index d141a8804f..94167d6cea 100644
--- a/distutils/command/build_scripts.py
+++ b/distutils/command/build_scripts.py
@@ -112,27 +112,7 @@ def _copy_script(self, script, outfiles, updated_files):
                 executable = os.fsencode(executable)
                 post_interp = shebang_match.group(1) or b''
                 shebang = b"#!" + executable + post_interp + b"\n"
-                # Python parser starts to read a script using UTF-8 until
-                # it gets a #coding:xxx cookie. The shebang has to be the
-                # first line of a file, the #coding:xxx cookie cannot be
-                # written before. So the shebang has to be decodable from
-                # UTF-8.
-                try:
-                    shebang.decode('utf-8')
-                except UnicodeDecodeError:
-                    raise ValueError(
-                        "The shebang ({!r}) is not decodable "
-                        "from utf-8".format(shebang))
-                # If the script is encoded to a custom encoding (use a
-                # #coding:xxx cookie), the shebang has to be decodable from
-                # the script encoding too.
-                try:
-                    shebang.decode(encoding)
-                except UnicodeDecodeError:
-                    raise ValueError(
-                        "The shebang ({!r}) is not decodable "
-                        "from the script encoding ({})"
-                        .format(shebang, encoding))
+                self._validate_shebang(shebang, encoding)
                 with open(outfile, "wb") as outf:
                     outf.write(shebang)
                     outf.writelines(f.readlines())
@@ -161,3 +141,28 @@ def _change_mode(self, file):
             log.info("changing mode of %s from %o to %o",
                      file, oldmode, newmode)
             os.chmod(file, newmode)
+
+    @staticmethod
+    def _validate_shebang(shebang, encoding):
+        # Python parser starts to read a script using UTF-8 until
+        # it gets a #coding:xxx cookie. The shebang has to be the
+        # first line of a file, the #coding:xxx cookie cannot be
+        # written before. So the shebang has to be decodable from
+        # UTF-8.
+        try:
+            shebang.decode('utf-8')
+        except UnicodeDecodeError:
+            raise ValueError(
+                "The shebang ({!r}) is not decodable "
+                "from utf-8".format(shebang))
+
+        # If the script is encoded to a custom encoding (use a
+        # #coding:xxx cookie), the shebang has to be decodable from
+        # the script encoding too.
+        try:
+            shebang.decode(encoding)
+        except UnicodeDecodeError:
+            raise ValueError(
+                "The shebang ({!r}) is not decodable "
+                "from the script encoding ({})"
+                .format(shebang, encoding))

From 7038cf2a659509b76847e463a3d3f47927986e0d Mon Sep 17 00:00:00 2001
From: "Jason R. Coombs" <jaraco@jaraco.com>
Date: Sun, 27 Mar 2022 11:44:07 -0400
Subject: [PATCH 11/12] Restore Setuptools compatibility.

---
 distutils/command/build_scripts.py | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/distutils/command/build_scripts.py b/distutils/command/build_scripts.py
index 94167d6cea..cc4ca1db83 100644
--- a/distutils/command/build_scripts.py
+++ b/distutils/command/build_scripts.py
@@ -15,6 +15,9 @@
 # check if Python is called on the first line with this expression
 shebang_pattern = re.compile(b'^#!.*python[0-9.]*([ \t].*)?$')
 
+# for Setuptools compatibility
+first_line_re = shebang_pattern
+
 
 class build_scripts(Command):
 

From e2f47dcfc2a8019254a7600c400062d5c392d944 Mon Sep 17 00:00:00 2001
From: "Jason R. Coombs" <jaraco@jaraco.com>
Date: Sun, 27 Mar 2022 12:02:25 -0400
Subject: [PATCH 12/12] In build_scripts, open scripts as text. Fixes
 pypa/distutils#124.

---
 distutils/command/build_scripts.py | 39 +++++++++++++++---------------
 1 file changed, 19 insertions(+), 20 deletions(-)

diff --git a/distutils/command/build_scripts.py b/distutils/command/build_scripts.py
index cc4ca1db83..e56511da09 100644
--- a/distutils/command/build_scripts.py
+++ b/distutils/command/build_scripts.py
@@ -12,8 +12,10 @@
 from distutils import log
 import tokenize
 
-# check if Python is called on the first line with this expression
-shebang_pattern = re.compile(b'^#!.*python[0-9.]*([ \t].*)?$')
+shebang_pattern = re.compile('^#!.*python[0-9.]*([ \t].*)?$')
+"""
+Pattern matching a Python interpreter indicated in first line of a script.
+"""
 
 # for Setuptools compatibility
 first_line_re = shebang_pattern
@@ -84,14 +86,12 @@ def _copy_script(self, script, outfiles, updated_files):
         # Always open the file, but ignore failures in dry-run mode
         # in order to attempt to copy directly.
         try:
-            f = open(script, "rb")
+            f = tokenize.open(script)
         except OSError:
             if not self.dry_run:
                 raise
             f = None
         else:
-            encoding, lines = tokenize.detect_encoding(f.readline)
-            f.seek(0)
             first_line = f.readline()
             if not first_line:
                 self.warn("%s is an empty file (skipping)" % script)
@@ -112,11 +112,10 @@ def _copy_script(self, script, outfiles, updated_files):
                         "python%s%s" % (
                             sysconfig.get_config_var("VERSION"),
                             sysconfig.get_config_var("EXE")))
-                executable = os.fsencode(executable)
-                post_interp = shebang_match.group(1) or b''
-                shebang = b"#!" + executable + post_interp + b"\n"
-                self._validate_shebang(shebang, encoding)
-                with open(outfile, "wb") as outf:
+                post_interp = shebang_match.group(1) or ''
+                shebang = "#!" + executable + post_interp + "\n"
+                self._validate_shebang(shebang, f.encoding)
+                with open(outfile, "w", encoding=f.encoding) as outf:
                     outf.write(shebang)
                     outf.writelines(f.readlines())
             if f:
@@ -150,22 +149,22 @@ def _validate_shebang(shebang, encoding):
         # Python parser starts to read a script using UTF-8 until
         # it gets a #coding:xxx cookie. The shebang has to be the
         # first line of a file, the #coding:xxx cookie cannot be
-        # written before. So the shebang has to be decodable from
+        # written before. So the shebang has to be encodable to
         # UTF-8.
         try:
-            shebang.decode('utf-8')
-        except UnicodeDecodeError:
+            shebang.encode('utf-8')
+        except UnicodeEncodeError:
             raise ValueError(
-                "The shebang ({!r}) is not decodable "
-                "from utf-8".format(shebang))
+                "The shebang ({!r}) is not encodable "
+                "to utf-8".format(shebang))
 
         # If the script is encoded to a custom encoding (use a
-        # #coding:xxx cookie), the shebang has to be decodable from
+        # #coding:xxx cookie), the shebang has to be encodable to
         # the script encoding too.
         try:
-            shebang.decode(encoding)
-        except UnicodeDecodeError:
+            shebang.encode(encoding)
+        except UnicodeEncodeError:
             raise ValueError(
-                "The shebang ({!r}) is not decodable "
-                "from the script encoding ({})"
+                "The shebang ({!r}) is not encodable "
+                "to the script encoding ({})"
                 .format(shebang, encoding))