Keep user sorting for license files

2 files changed, 29 insertions, 11 deletions

diff --git a/setuptools/dist.py b/setuptools/dist.py
index 5be83d70..4877d36b 100644
--- a/setuptools/dist.py
+++ b/setuptools/dist.py
@@ -581,13 +581,13 @@ class Distribution(_Distribution):
 
     def _finalize_license_files(self):
         """Compute names of all license files which should be included."""
-        files = set()
+        files: List[str] = []
         license_files: Optional[List[str]] = self.metadata.license_files
-        patterns: Set[str] = set(license_files) if license_files else set()
+        patterns: List[str] = license_files if license_files else []
 
         license_file: Optional[str] = self.metadata.license_file
-        if license_file:
-            patterns.add(license_file)
+        if license_file and license_file not in patterns:
+            patterns.append(license_file)
 
         if license_files is None and license_file is None:
             # Default patterns match the ones wheel uses
@@ -596,13 +596,15 @@ class Distribution(_Distribution):
             patterns = ('LICEN[CS]E*', 'COPYING*', 'NOTICE*', 'AUTHORS*')
 
         for pattern in patterns:
+            files_pattern: Set[str] = set()
             for path in iglob(pattern):
                 if path.endswith('~'):
                     continue
                 if path not in files and os.path.isfile(path):
-                    files.add(path)
+                    files_pattern.add(path)
+            files.extend(sorted(files_pattern))
 
-        self.metadata.license_files = sorted(files)
+        self.metadata.license_files = files
 
     # FIXME: 'Distribution._parse_config_files' is too complex (14)
     def _parse_config_files(self, filenames=None):  # noqa: C901
diff --git a/setuptools/tests/test_egg_info.py b/setuptools/tests/test_egg_info.py
index 2821a295..1d98d259 100644
--- a/setuptools/tests/test_egg_info.py
+++ b/setuptools/tests/test_egg_info.py
@@ -689,6 +689,17 @@ class TestEggInfo:
             'NOTICE-XYZ': "XYZ notice",
             }, ['LICENSE-ABC'], ['NOTICE-XYZ'],
             id="no_default_glob_patterns"),
+        pytest.param({
+            'setup.cfg': DALS("""
+                              [metadata]
+                              license_files =
+                                  LICENSE-ABC
+                                  LICENSE*
+                              """),
+            'LICENSE-ABC': "ABC license",
+            }, ['LICENSE-ABC'], [],
+            id="files_only_added_once",
+        ),
     ])
     def test_setup_cfg_license_files(
             self, tmpdir_cwd, env, files, incl_licenses, excl_licenses):
@@ -843,11 +854,13 @@ class TestEggInfo:
             "setup.cfg": DALS("""
                               [metadata]
                               license_files =
+                                  NOTICE*
                                   LICENSE*
                               """),
             "LICENSE-ABC": "ABC license",
             "LICENSE-XYZ": "XYZ license",
-            "NOTICE": "not included",
+            "NOTICE": "included",
+            "IGNORE": "not include",
         })
 
         environment.run_setup_py(
@@ -860,10 +873,13 @@ class TestEggInfo:
         license_file_lines = [
             line for line in pkg_info_lines if line.startswith('License-File:')]
 
-        # Only 'LICENSE-ABC' and 'LICENSE-XYZ' should have been matched
-        assert len(license_file_lines) == 2
-        assert "License-File: LICENSE-ABC" in license_file_lines
-        assert "License-File: LICENSE-XYZ" in license_file_lines
+        # Only 'NOTICE', LICENSE-ABC', and 'LICENSE-XYZ' should have been matched
+        # Also assert that order from license_files is keeped
+        assert license_file_lines == [
+            "License-File: NOTICE",
+            "License-File: LICENSE-ABC",
+            "License-File: LICENSE-XYZ",
+        ]
 
     def test_metadata_version(self, tmpdir_cwd, env):
         """Make sure latest metadata version is used by default."""