Dragging Bounds incorrect when image is rotated

[paulmer]

When an image has been rotated, it's often impossible to drag the image fully to one side in a single motion. It appears that the dragging boundaries are not rotated with the image. This problem appears to be present in both Safari 8.0.3 and Firefox 35.0.1 on Mac OS X, and applies to the 3/2/15 Git commit as well as previous versions.

To reproduce the problem, zoom into an image sufficiently so that only a portion of the full image fits the viewport. Drag the image so that an edge is aligned with the viewport, then rotate the image 90 degrees. The dragging distance will be limited by the distance the unrotated image extended beyond the viewport in the horizontal or vertical directions instead of how the rotated image extends beyond the viewport.

For an extreme example, zoom in so that the image is wider and taller than the view port, and scroll the image before rotating so that the viewport is aligned with the left edge and vertical middle of the image. It should be possible to scroll up and down but not to the left in the image. After rotating counter-clockwise 90 degrees, the top of the image should be off the left side of the viewport, but it is not possible to drag the image to the right to reveal the hidden top, but it is possible to drag the image up even though the left edge of the image is visible in the viewport.