Blank first line in a tangled file prevents src block execution

[Leo Alekseyev <dnquark@gmail.com>]

I have the following source block that I tangle to produce a short script:

#+begin_src sh :tangle code/get_wavs.sh
  #!/bin/bash
  for fn_in in "$@"; do
      fn_out=$(sed -e 's|\.3gp$||g' -e 's|$|.wav|g' <<< $fn_in)
      ffmpeg -i $fn_in -vn -f wav -acodec pcm_u8 $fn_out
  done
#+end_src

However, the tangled file has a blank first line.  As a result, I
can't seem to run this script either using sh -c, or by putting it
inside a code block.  In other words, the following line fails:

sh -c "code/test.sh data/salsa/20120308_av_jc/song2/*.3gp"
code/test.sh: 4: Syntax error: redirection unexpected

And, similarly, this fails

#+begin_src sh
  code/get_wavs.sh data/salsa/20120308_av_jc/song2/*.3gp
#+end_src


On the other hand, the script runs fine from the command line, or from
an org-mode shell: link, i.e. just running

code/test.sh data/salsa/20120308_av_jc/song2/*.3gp

at bash prompt produces the desired result.


I am not sure what the rules are about blank lines before the
hash-bang directive in Bash, and why in particular the blank line
seems to cause sh -c ... and orb-babel src execution to break, but the
current behavior seems broken.