[vazub]

When setting up bluetooth on my custom distro, I noticed that the device name was never properly resolved. Poking around new keventd implementation, and hwdb parsing feature in particular, revealed several issues that caused this incorrect behavior. Namely:

Issue 1. Properties after comments were dropped

A comment line ended the record being read. Comments are now skipped; only an empty line ends a record.

Issue 2. Lookup key as an argument was not processed and buffer was too small

Many hwdb invocations in the stock rules pass the key as an argument, e.g. hwdb 'evdev:name:$attr{name}:$attr{[dmi/id]modalias}'. The argument was ignored, so those rules (mouse, touchpad, joystick, sensor, name-based evdev, camera, ieee1394) looked up a synthesised key or nothing. The first non-option argument is now the key.

Additionally, the key buffer was 256 bytes and silently cut longer keys off. With typical DMI strings the name-based evdev key is 250 to 265 bytes, and 280 to 300 for the name+phys+ev form, so 256 is marginal. The buffer is now 1024 bytes and a key that still does not fit is skipped with a warning. The prefix is inserted in place, so there is no second buffer.

Issue 3. Uninitialised input ids were getting parsed

hwdb_input_key() parsed vendor, product and version from uninitialised buffers when an id/ file was missing.

Issue 4. Input keys were not built the way rules expect

The stock rules use

hwdb --subsystem=input --lookup-prefix=evdev:
hwdb --subsystem=input --lookup-prefix=id-input:modalias:

and the entries are evdev:input:b0003v... and id-input:modalias:input:b0003v..., i.e. the prefix followed by the
input modalias. keventd built evdev:input:b... and then added the prefix, giving evdev:evdev:input:..., which never matches. The key is now input:b.... The modalias attribute of the input device is used when present, because two of the seven id-input entries match on the capability list that the id/ files do not have.

Results with the real hwdb entries and the stock invocations:

invocation / device	before	after
evdev: prefix, device with modalias	nothing	EVDEV_ABS_00, EVDEV_ABS_01
evdev: prefix, id/ files only	nothing	same
id-input:modalias:, needs capability list	nothing	ID_INPUT_POINTINGSTICK=1

[troglobit]

Another great PR, for a slow maintainer, sorry again for taking so long!