Issue #29326: Ignores blank lines in ._pth files (Patch by Alexey Izbyshev)

Lib/test/test_site.py

@@ -511,16 +511,30 @@ class StartupImportTests(unittest.TestCase):
         os.unlink(_pth_file)
         os.unlink(exe_file)
 
+    @classmethod
+    def _calc_sys_path_for_underpth_nosite(self, sys_prefix, lines):
+        sys_path = []
+        for line in lines:
+            if not line or line[0] == '#':
+                continue
+            abs_path = os.path.abspath(os.path.join(sys_prefix, line))
+            sys_path.append(abs_path)
+        return sys_path
+
     @unittest.skipUnless(sys.platform == 'win32', "only supported on Windows")
     def test_underpth_nosite_file(self):
         libpath = os.path.dirname(os.path.dirname(encodings.__file__))
         exe_prefix = os.path.dirname(sys.executable)
-        exe_file = self._create_underpth_exe([
+        pth_lines = [
             'fake-path-name',
             *[libpath for _ in range(200)],
+            '',
             '# comment',
-            'import site'
-        ])
+        ]
+        exe_file = self._create_underpth_exe(pth_lines)
+        sys_path = self._calc_sys_path_for_underpth_nosite(
+            os.path.dirname(exe_file),
+            pth_lines)
 
         try:
             env = os.environ.copy()
@@ -529,14 +543,11 @@ class StartupImportTests(unittest.TestCase):
             rc = subprocess.call([exe_file, '-c',
                 'import sys; sys.exit(sys.flags.no_site and '
                 'len(sys.path) > 200 and '
-                '%r in sys.path and %r in sys.path and %r not in sys.path)' % (
-                    os.path.join(sys.prefix, 'fake-path-name'),
-                    libpath,
-                    os.path.join(sys.prefix, 'from-env'),
-                )], env=env)
+                'sys.path == %r)' % sys_path,
+                ], env=env)
         finally:
             self._cleanup_underpth_exe(exe_file)
-        self.assertEqual(rc, 0)
+        self.assertTrue(rc, "sys.path is incorrect")
 
     @unittest.skipUnless(sys.platform == 'win32', "only supported on Windows")
     def test_underpth_file(self):
@@ -545,23 +556,26 @@ class StartupImportTests(unittest.TestCase):
         exe_file = self._create_underpth_exe([
             'fake-path-name',
             *[libpath for _ in range(200)],
+            '',
             '# comment',
             'import site'
         ])
+        sys_prefix = os.path.dirname(exe_file)
         try:
             env = os.environ.copy()
             env['PYTHONPATH'] = 'from-env'
             env['PATH'] = '{};{}'.format(exe_prefix, os.getenv('PATH'))
             rc = subprocess.call([exe_file, '-c',
                 'import sys; sys.exit(not sys.flags.no_site and '
-                '%r in sys.path and %r in sys.path and %r not in sys.path)' % (
-                    os.path.join(sys.prefix, 'fake-path-name'),
+                '%r in sys.path and %r in sys.path and %r not in sys.path and '
+                'all("\\r" not in p and "\\n" not in p for p in sys.path))' % (
+                    os.path.join(sys_prefix, 'fake-path-name'),
                     libpath,
-                    os.path.join(sys.prefix, 'from-env'),
+                    os.path.join(sys_prefix, 'from-env'),
                 )], env=env)
         finally:
             self._cleanup_underpth_exe(exe_file)
-        self.assertEqual(rc, 0)
+        self.assertTrue(rc, "sys.path is incorrect")
 
 
 if __name__ == "__main__":

Misc/ACKS

@@ -684,6 +684,7 @@ John Interrante
 Bob Ippolito
 Roger Irwin
 Atsuo Ishimoto
+Alexey Izbyshev
 Kasia Jachim
 Adam Jackson
 Ben Jackson

Misc/NEWS

@@ -871,6 +871,8 @@ Library
 Windows
 -------
 
+- Issue #29326: Ignores blank lines in ._pth files (Patch by Alexey Izbyshev)
+
 - Issue #28164: Correctly handle special console filenames (patch by Eryk Sun)
 
 - Issue #29409: Implement PEP 529 for io.FileIO (Patch by Eryk Sun)

PC/getpathp.c

@@ -560,7 +560,7 @@ read_pth_file(const wchar_t *path, wchar_t *prefix, int *isolated, int *nosite)
         char *p = fgets(line, MAXPATHLEN + 1, sp_file);
         if (!p)
             break;
-        if (*p == '\0' || *p == '#')
+        if (*p == '\0' || *p == '\r' || *p == '\n' || *p == '#')
             continue;
         while (*++p) {
             if (*p == '\r' || *p == '\n') {