Merge branch 'refs/heads/t/attribute_fix'

com_setatt() was broken if more than 32 attributes are defined. The
branch merged in this commit contains a fix for this bug, and a new
test that exercises the code related to attributes.

Was cooking in next for six weeks.

* refs/heads/t/attribute_fix:
  manual: Add realpath to list of packages.
  Add test that exercises attribute code.
  test-lib: Canonicalize test_dir.
  attribute: Avoid shifting 32 bit integers.

diff --combined web/manual.m4
index 59abc5385f9eb5cdcc4a21bfbdb6a30567fa6b90,4ba2f6c17823f15de90d72920a5ef39160512b3f..addc24589b9fb5958273b54d6542edce1c2615b8
--- 1/web/manual.m4
--- 2/web/manual.m4
+++ b/web/manual.m4
@@@ -208,7 -208,7 +208,7 @@@ For the impatient
        cd osl && make && sudo make install && sudo ldconfig
        sudo apt-get install autoconf libssl-dev help2man gengetopt \
                libmad0-dev libid3tag0-dev libasound2-dev libvorbis-dev \
-               libfaad-dev libspeex-dev libFLAC-dev libsamplerate-dev \
+               libfaad-dev libspeex-dev libFLAC-dev libsamplerate-dev realpath \
                libasound2-dev libao-dev libreadline-dev libncurses-dev \
                libopus-dev
  
@@@ -956,13 -956,12 +956,13 @@@ is not set, the empty string is matche
        frequency ~ <num>
        channels ~ <num>
        num_played ~ <num>
 +      image_id ~ <num>
 +      lyrics_id ~ <num>
  
  Takes a comparator ~ of the set {<, =, <=, >, >=, !=} and a number
  <num>. Matches an audio file iff the condition <val> ~ <num> is
  satisfied where val is the corresponding value of the audio file
 -(value of the year tag, bitrate in kbit/s, frequency in Hz, channel
 -count, play count).
 +(value of the year tag, bitrate in kbit/s, etc.).
  
  The year tag is special as its value is undefined if the audio file
  has no year tag or the content of the year tag is not a number. Such