bug#61813: 29.0.60; treesit-indent-region can move parts of a C comment to column 0

[Daniel Martín]

Steps to reproduce the problem:

emacs -Q
C-x b sample RET
M-x c-ts-mode

Paste the following code:

/*
  First part of a comment.

  Second part of a comment.
 */

C-x h
TAB

Expected results:

The buffer is not modified.

Actual results:

/*
  First part of a comment.

Second part of a comment.
 */

This bug does not happen if I TAB the original code line by line.  It
also does not happen if I remove the extra newline between "First part
of a comment." and "Second part of a comment.".