21f7fd1032
The main issues: - The addition of the root's dstart entry during lfsr_format throws off our mtree tests. It's a bit of a hack, but for now I am just manually deleting the root's dstart entry at the beginning of each tests. It might be possible to make the mtree tests work around the root's dstart, but it seems to cause problems for when exactly the mtree splits. - btree dnamelookup and mdir dnamelookup need different things from the rbyd dnamelookup when the dname is not found. The btree lookup needs the largest branch smaller than the dname, since this is the "bucket" containing our dname, while the mdir dnamelookup needs the id that _follows_ the id smaller than the dname, since insertion causes all ids >= the inserting id to shift up. The solution here is to make rbyd dnamelookup behave as expected by btree dnamelookup. btree needs more info about the branch (weight mostly), so this avoids more issues. mdir dnamelookup adjusts the id as needed, which costs a bit of code, but makes things work. Fortunately, mdir dnamelookup can assume the weight is 1, which simplifies things a bit.