bug#17908: [PATCH] dist: ordering of files in DIST_COMMON is deterministic now

[Stefano Lattarini]

It had likely stopped being deterministic due to the new perl behavior
of having non-deterministic order of numerating hash keys:
<http://search.cpan.org/dist/perl-5.18.0/pod/perldelta.pod#Hash_randomization>
<http://onionstand.blogspot.ie/2012/12/are-you-relying-on-hash-keys-being.html>

See also similar commit v1.14-19-g52e6404.

Fixes automake bug http://debbugs.gnu.org/17908

* bin/automake.in (handle_dist): Sort @dist_common.
(print_autodist_files): Swap invocations of 'sort' and 'uniq', for
consistency with the new code in 'handle_dist' and to get rid of a
minor hack.
* NEWS: Update.

Signed-off-by: Stefano Lattarini <address@hidden>
---
 NEWS            |  6 +++++-
 bin/automake.in | 14 +++++++-------
 2 files changed, 12 insertions(+), 8 deletions(-)

diff --git a/NEWS b/NEWS
index bdc9bb9..5d14c5e 100644
--- a/NEWS
+++ b/NEWS
@@ -116,6 +116,10 @@ New in 1.14.2:
     risks causing "Arg list too long" for projects using automatic
     dependency tracking and having a ton of source files (bug#18744).
 
+  - Automake tries to offer a more deterministic for generated Makefiles,
+    in the face of the newly-introduced randomization for hash keys order
+    in Perl 5.18.
+
 ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
 
 New in 1.14.1:
@@ -131,7 +135,7 @@ New in 1.14.1:
     was only relevant when the number of python files was high (which is
     unusual in practice).
 
-  - Automake try to offer a more reproducible output for warning messages,
+  - Automake try to offer a more deterministic output for warning messages,
     in the face of the newly-introduced randomization for hash keys order
     in Perl 5.18.
 
diff --git a/bin/automake.in b/bin/automake.in
index 283d1bb..7851454 100644
--- a/bin/automake.in
+++ b/bin/automake.in
@@ -3714,10 +3714,13 @@ sub handle_dist ()
        }
     }
 
-  # Files to distributed.  Don't use ->value_as_list_recursive
-  # as it recursively expands '$(dist_pkgdata_DATA)' etc.
+  # Files to distributed.  Don't use ->value_as_list_recursive as it
+  # recursively expands '$(dist_pkgdata_DATA)' etc.
+  # Use 'sort' so that the expansion of $(DIST_COMMON) in the generated
+  # Makefile is deterministic, in face of m4 and/or perl randomizations
+  # (see automake bug#17908).
   my @dist_common = split (' ', rvar ('DIST_COMMON')->variable_value);
-  @dist_common = uniq (@dist_common);
+  @dist_common = uniq (sort @dist_common);
   variable_delete 'DIST_COMMON';
   define_pretty_variable ('DIST_COMMON', TRUE, INTERNAL, @dist_common);
 
@@ -7883,10 +7886,7 @@ sub generate_makefile
 # Helper function for usage().
 sub print_autodist_files
 {
-  # NOTE: we need to call our 'uniq' function with the leading '&'
-  # here, because otherwise perl complains that "Unquoted string
-  # 'uniq' may clash with future reserved word".
-  my @lcomm = sort (&uniq (@_));
+  my @lcomm = uniq (sort @_);
 
   my @four;
   format USAGE_FORMAT =
-- 
2.1.3