Previously, the API for ltree_strncasecmp() took two inputs but only one length (that of the smaller input). It truncated the larger input to that length, but that could break a multibyte sequence. Change the API to be a check for prefix equality (possibly case-insensitive) instead, which is all that's needed by the callers. Also, provide the lengths of both inputs. Reviewed-by: Chao Li <li.evan.chao@gmail.com> Reviewed-by: Peter Eisentraut <peter@eisentraut.org> Discussion: https://postgr.es/m/5f65b85740197ba6249ea507cddf609f84a6188b.camel%40j-davis.com Backpatch-through: 14