Fix _dump_command to use repr() and avoid data loss

Author: furkanonder

Lib/dbm/__main__.py

@@ -22,10 +22,8 @@ def _whichdb_command(filenames):
 def _dump_command(filename):
     try:
         with dbm_open(filename, "r") as db:
-            for key in db.keys():
-                key_str = key.decode("utf-8", errors="replace")
-                value_str = db[key].decode("utf-8", errors="replace")
-                print(f"{key_str}: {value_str}")
+            for key in db:
+                print(f"{key!r}: {db[key]!r}")
         return 0
     except error:
         print(f"Error: Database '{filename}' not found", file=sys.stderr)

Lib/test/test_dbm.py

@@ -364,8 +364,8 @@ def test_whichdb_output_format(self):
 
     def test_dump_command(self):
         output = self.run_cmd_ok('--dump', self.test_db)
-        self.assertIn(b'key1: value1', output)
-        self.assertIn(b'key2: value2', output)
+        self.assertIn(b"b'key1': b'value1'", output)
+        self.assertIn(b"b'key2': b'value2'", output)
 
     def test_dump_empty_database(self):
         output = self.run_cmd_ok('--dump', self.empty_db)