Add escaping to license field

changelog.d/2640.change.rst

@@ -0,0 +1 @@
+Fixed handling of multiline license strings. - by :user:`cdce8p`

setuptools/dist.py

@@ -120,7 +120,7 @@ def read_pkg_file(self, file):
     self.author_email = _read_field_from_msg(msg, 'author-email')
     self.maintainer_email = None
     self.url = _read_field_from_msg(msg, 'home-page')
-    self.license = _read_field_from_msg(msg, 'license')
+    self.license = _read_field_unescaped_from_msg(msg, 'license')
 
     if 'download-url' in msg:
         self.download_url = _read_field_from_msg(msg, 'download-url')
@@ -188,7 +188,8 @@ def write_field(key, value):
             if attr_val is not None:
                 write_field(field, attr_val)
 
-    write_field('License', self.get_license())
+    license = rfc822_escape(self.get_license())
+    write_field('License', license)
     if self.download_url:
         write_field('Download-URL', self.download_url)
     for project_url in self.project_urls.items():

setuptools/tests/test_dist.py

@@ -116,6 +116,10 @@ def __read_test_cases():
         ('Metadata Version 2.1: Long Description Content Type', params(
             long_description_content_type='text/x-rst; charset=UTF-8',
         )),
+        ('License', params(license='MIT', )),
+        ('License multiline', params(
+            license='This is a long license \nover multiple lines',
+        )),
         pytest.param(
             'Metadata Version 2.1: Provides Extra',
             params(provides_extras=['foo', 'bar']),

setuptools/tests/test_egg_info.py

@@ -886,6 +886,37 @@ def test_project_urls(self, tmpdir_cwd, env):
         assert expected_line in pkg_info_lines
         assert 'Metadata-Version: 1.2' in pkg_info_lines
 
+    def test_license(self, tmpdir_cwd, env):
+        """Test single line license."""
+        self._setup_script_with_requires(
+            "license='MIT',"
+        )
+        code, data = environment.run_setup_py(
+            cmd=['egg_info'],
+            pypath=os.pathsep.join([env.paths['lib'], str(tmpdir_cwd)]),
+            data_stream=1,
+        )
+        egg_info_dir = os.path.join('.', 'foo.egg-info')
+        with open(os.path.join(egg_info_dir, 'PKG-INFO')) as pkginfo_file:
+            pkg_info_lines = pkginfo_file.read().split('\n')
+        assert 'License: MIT' == pkg_info_lines[7]
+
+    def test_license_escape(self, tmpdir_cwd, env):
+        """Test license is escaped correctly if longer than one line."""
+        self._setup_script_with_requires(
+            "license='This is a long license text \\nover multiple lines',"
+        )
+        code, data = environment.run_setup_py(
+            cmd=['egg_info'],
+            pypath=os.pathsep.join([env.paths['lib'], str(tmpdir_cwd)]),
+            data_stream=1,
+        )
+        egg_info_dir = os.path.join('.', 'foo.egg-info')
+        with open(os.path.join(egg_info_dir, 'PKG-INFO')) as pkginfo_file:
+            pkg_info_lines = pkginfo_file.read().split('\n')
+        assert 'License: This is a long license text ' == pkg_info_lines[7]
+        assert '        over multiple lines' == pkg_info_lines[8]
+
     def test_python_requires_egg_info(self, tmpdir_cwd, env):
         self._setup_script_with_requires(
             """python_requires='>=2.7.12',""")