Weird behavior autocrop in some projections

[Henk Tijdink]

As requested in bug report 806153 a new bug report of the weird behavior of the autocrop function with some projections. Perhaps going to some extreme situations this fault comes. With normal use you don't notice and get it.
Tested it under Windows XP 32 bits and now with Hugin 2011.4 beta1 too.

Created the panorama and in the preview straightened and centred it.
Following observed with the following projections

Stereographic projection.
Fit
Autocrop.
Right: 2616 Bottom: 2049
Left : 2014 Top : 896
This gives a rectangle of 602x1153=691416.

Doing a manual crop
Right: 2865 Bottom: 1616
Left : 81 Top : 1334
This gives a rectangle of 2784x282=785088.

Panini
Fit -> FOV 304x102.
Autocrop.
Right: 2878 Bottom: 811
Left : 1768 Top : 0
This gives a rectangle of 1110x811=900210.

Doing a manual crop
Right: 2882 Bottom: 692
Left : 70 Top : 122
This gives a rectangle of 2812x570=1532840.

When I change the vertical FOV to 101 it crops all right, like the manual crop.

Equirectangular Panini
Fit -> FOV 304x102
Autocrop works allright

But when changing the vertical FOV to 109 or larger it goes wrong
Autocrop.
Right: 2879 Bottom: 516
Left : 1832 Top : 0
This gives a rectangle of 1047x516=540252.

Doing a manual crop
Right: 2882 Bottom: 392
Left : 70 Top : 47
This gives a rectangle of 2812x345=970140.

Attached is the PTO file.

Kind regards,
Henk Tijdink

[tmodes (tmodes)]

Tried to fix in changeset 56e9e6ad6445
Needs testing, if this does not break other projects.