Index: Lib/pdb.py
===================================================================
--- Lib/pdb.py	(revision 78295)
+++ Lib/pdb.py	(working copy)
@@ -1211,7 +1211,7 @@
         self._wait_for_mainpyfile = 1
         self.mainpyfile = self.canonic(filename)
         self._user_requested_quit = 0
-        with open(filename, "rb") as fp:
+        with open(filename, "r") as fp:
             statement = "exec(compile(%r, %r, 'exec'))" % \
                         (fp.read(), self.mainpyfile)
         self.run(statement)
Index: Lib/test/test_pdb.py
===================================================================
--- Lib/test/test_pdb.py	(revision 78295)
+++ Lib/test/test_pdb.py	(working copy)
@@ -5,7 +5,9 @@
 import os
 import sys
 import doctest
+import subprocess
 import tempfile
+import unittest
 
 from test import support
 # This little helper class is essential for testing pdb under doctest.
@@ -125,7 +127,29 @@
     (Pdb) continue
     """
 
+class Tester7964(unittest.TestCase):
+    # Issue 7964 identifies a bug in the way script files are opened
+    # which causes scripts with windows newlines to fail when invoked
+    # by pdb
+    test_fn = '.\\test7964.py'
 
+    def test_issue7964(self):
+		# open the file as binary so we can force \r\n newline
+        with open(self.test_fn, 'wb') as f:
+            f.write(b'print("hello world")\r\n')
+        cmd = [sys.executable, '-m', 'pdb', self.test_fn,]
+        proc = subprocess.Popen(cmd,
+            stdout=subprocess.PIPE,
+            stdin=subprocess.PIPE,
+            stderr=subprocess.STDOUT,
+            )
+        stdout, stderr = proc.communicate(b'quit\n')
+        self.assertNotIn(b'SyntaxError', stdout, "Got a syntax error running hello world under PDB")
+
+    def tearDown(self):
+        if os.path.isfile(self.test_fn):
+            os.remove(self.test_fn)
+
 def test_main():
     from test import test_pdb
     support.run_doctest(test_pdb, verbosity=True)
@@ -133,3 +157,4 @@
 
 if __name__ == '__main__':
     test_main()
+    unittest.main()