bug#18215: 24.4.50; OSX 10.6.8; set-frame-size by pixelwise does not work following `make-fame`.

[martin rudalics]

Thanks for the dumps.  As I expected, the difference of 6 pixels is
explained by the different values for the fringes, namely ...

> Here is the `(window--dump-frame)` printout for the June 1, 2014 Emacs Trunk 
build:
>
>      frame pixel: 1920 x 1058   cols/lines: 174 x 52   units: 11 x 20
>      frame text pixel: 1894 x 1054   cols/lines: 172 x 52
>      tool: 0  scroll: 0  fringe: 22  border: 2  right: 0  bottom: 0

... 22 pixels for the June build, and ...

> Here is the `(window--dump-frame)` printout for the August 8, 2014 patched 
Emacs Trunk build:
>
>      frame pixel: 1914 x 1058   cols/lines: 175 x 52   units: 11 x 20
>      frame text pixel: 1894 x 1054   cols/lines: 172 x 52
>      tool: 0  scroll: 0/0  fringe: 16  border: 2  right: 0  bottom: 0

.... 16 pixels for the August build.  The reason for this is that the
June build still rounds the fringe widths to the next multiple of the
frame's character width which is listed as 11 in your dump (compare
"units: 11 x 20") while the August build does not round any more.

Basically, you should be able to fix this problem in a more generic way
either by maximizing the frame instead of calculating its sizes by hand
or by making the calculations use terms like those used in
`window--dump-frame' where you should see how the "pixel size" of a
frame relates to its "text size".  In addition, you would have to
platform-wise include the sizes of the outer borders and the frame
decorations used by the respective window manager.  I plan to provide
these values within Emacs but since I do no have access to all platforms
this might still take some time.

> Both of the printouts were made using the settings contained in the initial 
bug report.

It's not entirely clear to me how the values reported here relate to the
values of

>     (setq-default left-fringe-width 10)
>
>     (setq-default right-fringe-width 0)

you report later.  Do your fringes appear as if they had this width (10
pixels for the left and 0 pixels for the right) or do they look as in
the dump (8 pixels on the left and the right, I presume)?

martin