Line Continuation Bugs & Patch

[Ein Terakawa]

Emacs-21 currently has a number of bugs concerning line continuation.
That is mainly in the code which handle !it->truncate_lines_p.
I checked Emacs-21.1 , Emacs-21.2 and one in the cvs tree (21.2.50).

I admit this bug report does not conform to the guideline.
But It was much fun to fix bugs than to report it and just wait.
So I created a patch. Although it may not be well prepared to be
inspected by Emacs core developers, it fixes bugs. And Emacs works
as fine as not fixed one dose.

Here, I just wanted to announce that there are bugs and I'm working on it.
If it's needed, I'm willing to discuss the problems on emacs-devel.
Boring bug description should be done first, though.


This is the patch. 
http://applause.elfmimi.jp/emacs-lisp/emacs-21.1-proper-continuation-20020518.diff.gz
And some documentation in my mother tongue (Japanese).
http://applause.elfmimi.jp/emacs-lisp/emacs-21.1-proper-continuation-20020518-ja.txt

Structs, macros and functions get affected by:
 struct glyph_row
 MATRIX_ROW_CONTINUATION_LINE_P
 MATRIX_ROW_ENDS_IN_MIDDLE_OF_CHAR_P
 compute_motion 
 buffer_posn_from_coords
 Fvertical_motion
 window_scroll_pixel_based
 start_display
 move_it_in_display_line_to
 move_it_to
 move_it_vertically_backward
 move_it_by_lines
 try_window
 try_window_id
 display_line
----
Ein Terakawa <applause@elfmimi.jp>