[FYI] {maint} refactor: fix few "inverted boolean" usages

[Stefano Lattarini]

In some subroutines, we used a return value of 0 to indicate success,
and a return status of 1 to indicate failure.  That was not very
consistent with the perl interpretation of 0 as a false value and 1 as
a true value.  So we now invert the meaning of the exit statuses.

* lib/Automake/Options.pm (_process_option_list): Here.
(process_global_option_list, process_option_list): And by reflex,
here as well.
* bin/automake.in (handle_options): And here.
(generate_makefile, scan_autoconf_traces): Adjust.

Signed-off-by: Stefano Lattarini <address@hidden>
---
 bin/automake.in         | 10 +++++-----
 lib/Automake/Options.pm | 22 ++++++++++++----------
 2 files changed, 17 insertions(+), 15 deletions(-)

diff --git a/bin/automake.in b/bin/automake.in
index 3614b6b..0aef771 100644
--- a/bin/automake.in
+++ b/bin/automake.in
@@ -1148,7 +1148,7 @@ sub handle_silent ()
 ################################################################
 
 
-# Handle AUTOMAKE_OPTIONS variable.  Return 1 on error, 0 otherwise.
+# Handle AUTOMAKE_OPTIONS variable.  Return 0 on error, 1 otherwise.
 sub handle_options ()
 {
   my $var = var ('AUTOMAKE_OPTIONS');
@@ -1162,7 +1162,7 @@ sub handle_options ()
       my @options = map { { option => $_->[1], where => $_->[0] } }
                        $var->value_as_list_recursive (cond_filter => TRUE,
                                                       location => 1);
-      return 1 if process_option_list (@options);
+      return 0 unless process_option_list (@options);
     }
 
   if ($strictness == GNITS)
@@ -1172,7 +1172,7 @@ sub handle_options ()
       set_option ('check-news', INTERNAL);
     }
 
-  return 0;
+  return 1;
 }
 
 # shadow_unconditionally ($varname, $where)
@@ -5280,7 +5280,7 @@ EOF
            {
              my @opts = split (' ', $args[1]);
              @opts = map { { option => $_, where => $where } } @opts;
-             exit $exit_code if process_global_option_list (@opts);
+             exit $exit_code unless process_global_option_list (@opts);
            }
        }
       elsif ($macro eq 'AM_MAINTAINER_MODE')
@@ -7731,7 +7731,7 @@ sub generate_makefile
   $relative_dir = dirname ($makefile);
 
   read_main_am_file ($makefile_am, $makefile_in);
-  if (handle_options)
+  if (not handle_options)
     {
       # Process buffered warnings.
       flush_messages;
diff --git a/lib/Automake/Options.pm b/lib/Automake/Options.pm
index e87fb05..f745d3a 100644
--- a/lib/Automake/Options.pm
+++ b/lib/Automake/Options.pm
@@ -241,7 +241,7 @@ These functions should be called at most once for each set 
of options
 having the same precedence; i.e., do not call it twice for two options
 from C<AM_INIT_AUTOMAKE>.
 
-Return 1 on error, 0 otherwise.
+Return 0 on error, 1 otherwise.
 
 =cut
 
@@ -323,20 +323,20 @@ sub _process_option_list (\%@)
           # Obsolete (and now removed) de-ANSI-fication support.
           error ($where,
                  "automatic de-ANSI-fication support has been removed");
-          return 1;
+          return 0;
         }
       # TODO: Remove this special check in Automake 3.0.
       elsif ($_ eq 'cygnus')
         {
           error $where, "support for Cygnus-style trees has been removed";
-          return 1;
+          return 0;
         }
       # TODO: Remove this special check in Automake 3.0.
       elsif ($_ eq 'dist-lzma')
         {
           error ($where, "support for lzma-compressed distribution " .
                          "archives has been removed");
-          return 1;
+          return 0;
         }
       # TODO: Make this a fatal error in Automake 2.0.
       elsif ($_ eq 'dist-shar')
@@ -360,15 +360,17 @@ sub _process_option_list (\%@)
         }
       elsif ($_ eq 'tar-v7' || $_ eq 'tar-ustar' || $_ eq 'tar-pax')
         {
-          return 1
-            unless _option_is_from_configure ($_, $where);
+          if (not _option_is_from_configure ($_, $where))
+            {
+              return 0;
+            }
           for my $opt ('tar-v7', 'tar-ustar', 'tar-pax')
             {
               next
                 if $opt eq $_ or ! exists $options->{$opt};
               error ($where,
                      "options '$_' and '$opt' are mutually exclusive");
-              return 1;
+              return 0;
             }
         }
       elsif (/^\d+\.\d+(?:\.\d+)?[a-z]?(?:-[A-Za-z0-9]+)?$/)
@@ -378,7 +380,7 @@ sub _process_option_list (\%@)
             {
               error ($where, "require Automake $_, but have $VERSION",
                      uniq_scope => US_GLOBAL);
-              return 1;
+              return 0;
             }
         }
       elsif (/^(?:--warnings=|-W)(.*)$/)
@@ -389,7 +391,7 @@ sub _process_option_list (\%@)
       elsif (! _is_valid_easy_option $_)
         {
           error ($where, "option '$_' not recognized");
-          return 1;
+          return 0;
         }
     }
   # We process warnings here, so that any explicitly-given warning setting
@@ -401,7 +403,7 @@ sub _process_option_list (\%@)
           "unknown warning category '$w->{'cat'}'"
         if switch_warning $w->{cat};
     }
-  return 0;
+  return 1;
 }
 
 sub process_option_list (@)
-- 
1.8.3.rc0.19.g7e6a0cc