gh-140950: Read pushed shlex source after EOF

Author: ThanhNguyxn

Lib/shlex.py

@@ -81,6 +81,7 @@ def push_source(self, newstream, newfile=None):
         self.infile = newfile
         self.instream = newstream
         self.lineno = 1
+        self.state = ' '
         if self.debug:
             if newfile is not None:
                 print('shlex: pushing to file %s' % (self.infile,))

Lib/test/test_shlex.py

@@ -179,6 +179,16 @@ def testCompat(self):
                              "%s: %s != %s" %
                              (self.data[i][0], l, self.data[i][1:]))
 
+    def test_push_source_after_eof(self):
+        for posix in (False, True):
+            with self.subTest(posix=posix):
+                lexer = shlex.shlex('a', posix=posix)
+                self.assertEqual(lexer.get_token(), 'a')
+                self.assertEqual(lexer.get_token(), lexer.eof)
+                lexer.push_source('b')
+                self.assertEqual(lexer.get_token(), 'b')
+                self.assertEqual(lexer.get_token(), lexer.eof)
+
     def testSyntaxSplitAmpersandAndPipe(self):
         """Test handling of syntax splitting of &, |"""
         # Could take these forms: &&, &, |&, ;&, ;;&

Misc/NEWS.d/next/Library/2026-02-07-16-55-00.gh-issue-140950.Jk2mQp.rst

@@ -0,0 +1,2 @@
+Fix :meth:`shlex.shlex.push_source` so a new source pushed after EOF is read
+correctly instead of being skipped.