u8g_DrawBox() with h=0 corrupts display

[francescolavra]

If the u8g_DrawBox() function in csrc/u8g_rect.c is called with the h argument set to 0, it corrupts the display by drawing a box that covers the entire height of the screen. This is because the body in the while() loop in u8g_draw_box() is executed before checking the value of the h argument.
This can be fixed by replacing the do {} while() construct with a simple while() loop:

while( h != 0 )
{
  u8g_draw_hline(u8g, x, y, w);
  y++;    
  h--;
}

[olikraus]

True, but Code size will be higher.

[olikraus]

Well... I can add this...

[AnHardt]

A box with height 0 is still a line. For that, at least one line is required. How about changing the condition to h > 0

[francescolavra]

A box with height 0 is still a line

Why? This wouldn't be consistent with the current implementation, where a line corresponds to a box with height 1, not 0. Also, u8g_DrawBox() doesn't draw anything when called with width 0.