Merge branch 'missing-fixes' into maint

* missing-fixes:
  missing: don't try to re-run tar with a munged command line
  missing: inform the user if GNU tar is called
  missing: if GNU tar exists but fails when called, give up
  missing: miscellaneous fixlets

diff --cc ChangeLog
index ea92d23,0a7a514..18a0432
--- 1/ChangeLog
--- 2/ChangeLog
+++ b/ChangeLog
@@@ -1,10 -1,46 +1,53 @@@
  2011-12-22  Stefano Lattarini  <stefano.lattarini@gmail.com>
+ 
+       missing: don't try to re-run tar with a munged command line
+       * lib/missing: If the default `tar' program fails with the given
+       arguments, and GNU tar is not available, don't try to re-run the
+       default `tar' with a munged command line (e.g., ditching possibly
+       unportable options), as that could be subtly alter the intended
+       semantics (and maybe even create a somewhat corrupted tarball).
+       Also, it's worth noting that the main purpose of the `missing'
+       script is to allow a non-developer to build the package in the
+       face of slightly-skewed timestamps, not to provide wrappers for
+       all the maintainer tools -- so we don't have to try too hard
+       when `missing' is just called to wrap `tar'.
+       * tests/missing-tar.test: New test.
+       * tests/Makefile.am (TESTS): Add it.
+ 
+ 2011-12-22  Stefano Lattarini  <stefano.lattarini@gmail.com>
+ 
+       missing: inform the user if GNU tar is called
+       * lib/missing: If the code trying to run GNU tar is reached, it
+       means that the previous attempt to run the default tar program
+       has failed, very likely producing some error message.  At this
+       point, just running GNU tar without further comments might be
+       confusing.
+ 
+ 2011-12-22  Stefano Lattarini  <stefano.lattarini@gmail.com>
+ 
+       missing: if GNU tar exists but fails when called, give up
+       * lib/missing: If the code trying to run GNU tar is reached,
+       don't continue if the invoked GNU tar program fails, as there
+       is little point in doing so (and can even be confusing and
+       counter-productive).
+ 
+ 2011-12-22  Stefano Lattarini  <stefano.lattarini@gmail.com>
+ 
+       missing: miscellaneous fixlets
+       * lib/missing: Some shells, such as Solaris or FreeBSD /bin/sh,
+       warn about missing programs before performing redirections.
+       Therefore, where we have to silently check whether a program
+       exists, perform redirections on a subshell.
+       Remove redundant uses of double-quotes in variable definitions.
+       Delete an extra blank line.
+ 
++2011-12-22  Stefano Lattarini  <stefano.lattarini@gmail.com>
 +
 +      maint: remove executable bit from automake.in
 +      * automake.in: This file is not meant to be executed, only to
 +      be preprocessed to create the `automake' script; so don't leave
 +      it executable.
 +
  2011-12-20  Peter Rosin  <peda@lysator.liu.se>
  
        tests: fix spurious failure on systems lacking unistd.h