mflm-skewDetectGray does not read from /dev/stdin

[danh]

The program mflm-skewDetectGray is conditionally invoked in RePublisherPreprocess as part of the procedure to create proxy images.

Sometimes it is invoked on /dev/stdin, with the input extracted from a tarfile by 7z.

This does not in general work, as the routine that mflm-skewDetectGray uses to read its input (which i believe is part of leptonica) will not read /dev/stdin. (The routine is pixRead().)

(Possible fixes would include either changing the way mflm-skewDetectGray is invoked, or changing the way it reads its input.)

Hank has also suggested that there's a slight chance that we might be able to avoid the issue by just changing /dev/stdin to something looking more like an ordinary file, such as a symbolic link to /dev/stdin.