  We calculate the ideal-glass-transition line for adhesive hard spheres in the
temperature-volume-fraction plane within the framework of the mode-coupling
theory. We find two intersecting lines, controlled by the hard-core and the
adhesive part of the potential respectively, giving rise to two different
mechanisms for structural arrest. In the glass region we identify the presence
of a glass-glass-transition line ending in a cusp bifurcation which causes,
even in the close by liquid region, a logarithmic decay of correlations.
