TpHeap: comparator results are not guaranteed to be -1, 0 and 1
TpHeap: comparator results are not guaranteed to be -1, 0 and 1

A GCompareFunc might return any negative or positive value if the two
values are not equal.

Bug: https://bugs.freedesktop.org/show_bug.cgi?id=68932
Reviewed-by: Simon McVittie <2b470b34502dbf3ba4bcc04ea7e64f4e0e104f33@collabora.co.uk>

Distrotech/telepathy-glib,Distrotech/telepathy-glib,Distrotech/telepathy-glib,Distrotech/telepathy-glib,Distrotech/telepathy-glib