Don't underflow the buffer in format_track_path() if it consists of whitespaces
tree040a58997c255d3155bb1a5d463e888508bc33dc
drwxr-xr-x - android
drwxr-xr-x - apps
drwxr-xr-x - backdrops
drwxr-xr-x - bootloader
drwxr-xr-x - debian
drwxr-xr-x - docs
drwxr-xr-x - firmware
drwxr-xr-x - flash
drwxr-xr-x - fonts
drwxr-xr-x - gdb
drwxr-xr-x - icons
drwxr-xr-x - lib
drwxr-xr-x - manual
drwxr-xr-x - rbutil
drwxr-xr-x - tools
drwxr-xr-x - uisimulator
drwxr-xr-x - utils
drwxr-xr-x - wps