negativeContainerIndex
ftp://ftp.de.debian.org/debian/pool/main/a/aptitude/aptitude_0.8.13.orig.tar.xz
aptitude-0.8.13/src/generic/problemresolver/search_graph.h:1423:12: warning: Either the condition 's.first_child!=-1' is redundant, otherwise there is negative array index -1. [negativeContainerIndex]