Re: coord conversion: frame->column_width set wrong?

[Jan D.]

address@hidden wrote:

> Tests:
> (coordinates-in-window-p '( 0 . 0) (selected-window))
> should return: (0 . 0)
> bug condition returns: nil
>
> (window-at 0 0)
> should return: #<window 3 on *scratch*> (or similar)
> bug condition returns: nil
>
> (coordinates-in-window-p '( 1 . 1) (selected-window))
> should return: (1 . 1)
> bug condition returns: (0.8571428571428571 . 0.9230769230769231)


> Name changes:
> coordinates-in-window-p uses the macro
> PIXEL_X_FROM_CANON_X -> FRAME_PIXEL_X_FROM_CANON_X
> which calls 
> CANON_X_UNIT -> FRAME_COLUMN_WIDTH
>
> On a window system, CANON_X_UNIT was a wrapper for
> FRAME_DEFAULT_FONT_WIDTH, defined in xterm.h, macterm.h, and w32term.h. 
> FRAME_DEFAULT_FONT_WIDTH no longer exists, and in its place,
> FRAME_COLUMN_WIDTH simply reads the field column_width from the frame
> data structure.  This value gets initialized to 1 in make_frame, but I
> couldn't find a place where it gets set based on the font.  Perhaps it
> isn't being set at all?

It is being set in xterm.c, x_new_font:
  FRAME_COLUMN_WIDTH (f) = FONT_WIDTH (FRAME_FONT (f));

The inconsistency seems to have another cause, see the thread
"Fix `window-at' and `coordinates-in-window-p'"

        Jan D.