bug#68284: [PATCH] Fix python-info-docstring-p bug in the 2nd line of a buffer

[kobarity]

Hi,

No matter what the first line of the buffer is, if the second line is
a string literal, `python-info-docstring-p` will misjudge it as a
docstring.  This issue can be reproduced as follows:

1. emacs -Q
2. Open a Python file whose contents are as follows:

#+begin_src python
import sys
"""Not a docstring."""
#+end_src

3. Locate the point at the string literal on the second line.
4. M-: (python-info-docstring-p)

Although this string literal is not a docstring, it returns t.
Therefore, in `python-mode` (not `python-ts-mode`), this string
literal is rendered in `font-lock-doc-face`.

This is the reason I changed some ERTs to "expected fail" in the
commit b7b82ecb2b4c2ce33c11e5388b692cd403ab55e6 of Bug#63622.

Attached is a patch to fix this bug and the above mentioned ERTs and
to restore ERTs I deleted by mistake in commit
6b2c8dc9050c5c0514fa404733ce1d4a37d00e39 of Bug#63844 (related to
Bug#63622).

--
In GNU Emacs 30.0.50 (build 3, x86_64-pc-linux-gnu, X toolkit, cairo
 version 1.16.0, Xaw scroll bars) of 2024-01-03 built on ubuntu
Repository revision: 91bc775b0c60342f118640001d2ce293d4f1f7ef
Repository branch: master
System Description: Ubuntu 22.04.3 LTS

0001-Fix-python-info-docstring-p-bug-in-the-2nd-line-of-a.patch
Description: Binary data