Bug#292973: postinst and prerm are #!/bin/sh scripts but use command -v

[Thomas Hood <jdthood@aglu.demon.nl>]

Package: dpkg-doc
Version: 1.10.26
Severity: minor

"command -v" is not POSIX.  However, the postinst and prerm scripts use
it and have #!/bin/sh at the top, so they violate policy 10.4.

Possible solutions:

* Using #!/bin/bash eliminates the 10.4 violation.  However, there
  remains the additional problem that "command -v" doesn't really work
  as a check whether or not a command is runnable.  The string that it
  outputs is not necessarily the pathname of an executable file.
  (See #291197.)
* Use the which program from debianutils.
* Use the trydo() function I posted to #291026.
* Use the findcommand() function posted by Tollef Fog Heen in #218530.
* Assume that install-docs is at /usr/sbin/install-docs and just use
  test -x /usr/sbin/install-docs


-- System Information:
Debian Release: 3.1
  APT prefers testing
  APT policy: (500, 'testing'), (50, 'unstable'), (1, 'experimental')
Architecture: i386 (i686)
Kernel: Linux 2.6.9
Locale: LANG=en_IE@euro, LC_CTYPE=en_IE@euro (charmap=ISO-8859-15)

-- no debconf information