This issue was reported in a comment to the issue #11503,
but is a different matter, so now I report it separately.

When I enter a forbidden start of line
character at a start of linfile:///usr/share/doc/HTML/index.htmle (of course,
the forbidden character was
put in the end of previous line), the I-beam pointer was located just
behind the previous character, not behind the forbidden start of line
character. This performance is strange.

Reproduce:You enter characters to the limit of the right in a page,
next enter punctuation mark which is forbidden to be a start of line.
The punctuation mark was forbidden to locate in the star of line so
that it was put in the end of previous line. After the forbidden
character was put in the end of line, the I-beam pointer is located in
front of the punctuation mark, never come behind it. In this
situation, or the I-beam pointer was in front of it, please push "Back
Space" key. Although the I-beam didn't point to the punctuation mark,
it will be deleted.
But we can avoid this problem by entering following characters behind
the punctuation mark.

This problem was confirmed by OO643C and 644_m1 developer release. I
will attach a helpful image of this issue.
It might be caused by the fault of information about pointer after
word wrapping process.