* pull-request/1425:
  revised bug53156.phpt
  Fix #53156: imagerectangle problem with point ordering

The stack overflow is caused by the recursive algorithm in combination with a
very large negative coordinate passed to gdImageFillToBorder(). As there is
already a clipping for large positive coordinates to the width and height of
the image, it seems to be consequent to clip to zero also.

Contrary to imagefilledrectangle(), imagerectangle() has the documented
limitation that the given points have to be the upper left and the lower right
corner, respectively. However, libgd already caters to upper right / lower left
pairs, and not catering to the other two combinations seems to be an oversight.

To avoid drawing the corner pixels twice, gdImageRectangle() draws the vertical
lines 2 points shorter than the actual side of the rectangle. However, this
causes "whiskers" for rectangles with height 0. This patch fixes this issue and
at the same time optimizes the algorithm by drawing only a single line for zero
height and zero width rectangles.