Environment

toml++ version and/or commit hash:
toml++ v2.5.0 037bfdd

Compiler:
g++ (Ubuntu 7.5.0-3ubuntu1~18.04) 7.5.0

C++ standard mode:
17

Target arch:
x86

Library configuration overrides:

Relevant compilation flags:

Describe the bug

If the table was created earlier, then the redefinition error is not called

Steps to reproduce (or a small repro code sample)

This is parsed without error:

[a.b.c.d]
  u = 6
[a]
  b.t = 8
[a.b]
  u = 0

Result:

[a.b]
t = 8
u = 0

    [a.b.c.d]
    u = 6

But this is with an error:

[a]
  b.t = 8
[a.b]
  u = 0

Result:

terminate called after throwing an instance of 'toml::v2::ex::parse_error'
  what():  Error while parsing table header: cannot redefine existing table 'a.b'

Additional information

For example with tomli (Python):

>>> tomli.loads("""
... [a.b.c.d]
... u = 6
... [a]
... b.t = 8
... [a.b]
... u = 0""")
Traceback (most recent call last):
...
tomli._parser.TOMLDecodeError: Can not declare ('a', 'b') twice (at line 6, column 5)
>>> tomli.loads("""[a]
... b.t = 8
... [a.b]
... u = 0""")
Traceback (most recent call last):
...
tomli._parser.TOMLDecodeError: Can not declare ('a', 'b') twice (at line 3, column 5)