nzujev [AT] gmail [DOT] com 03-Oct-2010 09:28
Be ready to surprise like this one.
array_merge renumbers numeric keys even if key is as string.
keys '1' & '2' will be updated to 0 & 1, but '1.1' & '1.2' remain the same, but they are numeric too (is_numeric('1.1') -> true)
It's better to use '+' operator or to have your own implementation for array_merge.