Trim whitespace from arguments of AC_INIT (#107986)

Specifically, all five arguments, if present, are passed through
m4_normalize before doing anything else with them.  For instance,
AC_INIT([  GNU  Hello  ], [1.0]) is now equivalent to
AC_INIT([GNU Hello], [1.0]).

As a consequence, newlines in the arguments to AC_INIT are now
converted to spaces and no longer trigger warnings.

Also, diagnose inappropriate contents of the fourth and fifth
arguments as well as the first three.  The fifth argument should be
“usable as-is in single- and double-quoted strings and quoted and
unquoted here-docs,” like the first three.  (This is the check
performed by _AC_INIT_LITERAL.)  The fourth argument (TARNAME) is used
to construct filenames, so apply an even more stringent test, namely
AS_LITERAL_WORD_IF.

Suggested by David A. Wheeler, who submitted a patch, but I didn’t
wind up using any of his code.

* lib/autoconf/general.m4 (_AC_INIT_LITERAL): Not necessary to check
  for newlines anymore.
  (_AC_INIT_PACKAGE): Pass all five arguments through m4_normalize
  before doing anything else with them.  New warning: apply
  _AC_INIT_LITERAL to fifth argument (URL).  New warning: complain
  if fourth argument (TARNAME) is not a literal word according to
  AS_LITERAL_WORD_IF.  Simplify a conditional by using m4_default.

* tests/base.at (AC_INIT with unusual version strings): Adjust to
  match above changes, add more subtests.

1 files changed, 11 insertions, 0 deletions

diff --git a/NEWS b/NEWS
index 000570e0..e0cdd069 100644
--- a/NEWS
+++ b/NEWS
@@ -194,6 +194,17 @@ GNU Autoconf NEWS - User visible changes.
 - AC_FC_LINE_LENGTH now documents the maximum portable length of
   "unlimited" Fortran source code lines to be 250 columns, not 254.
 
+- AC_INIT now trims extra white space from its arguments.  For instance,
+
+    AC_INIT([  GNU  Hello  ], [1.0])
+
+  will set PACKAGE_NAME to “GNU Hello”.
+
+- AC_INIT will now issue warnings (in the “syntax” category) for a
+  non-literal URL argument, and for a TARNAME argument which is either
+  non-literal or contains characters that should not be used in file
+  names (e.g. ‘*’).
+
 * Noteworthy changes in release 2.69 (2012-04-24) [stable]
 
 ** Autoconf now requires perl 5.6 or better (but generated configure