util.dbuffer: Simplify test case
An earlier theory involved the bug being related to collapsing multiple
items, so it exercised that too.
Also correct the comment, it referred to the space in "hello world" in
an earlier version before the test string was changed to "foobar", which
was what was tested in a REPL
syntax: glob
.hgignore
.luacheckcache
data
local
www_files
html/*
prosody.lua
prosody.cfg.lua
prosody.version
config.unix
*.patch
*.diff
*.orig
*.rej
*.save
*~
*.o
*.so
*.install
*.pid
*.log
*.err
*.debug
*.dll
*.exp
*.lib
*.obj
luacov.report.out
luacov.report.out.index
luacov.stats.out