X-Git-Url: http://git.shadowcat.co.uk/gitweb/gitweb.cgi?a=blobdiff_plain;f=lib%2Fbase.pm;h=8bcbb5f3cac4c2e37b7b4591df83d5ada97e33ca;hb=c1d8f74eb4326dca73e3ac3f73812dff8489ecf7;hp=b735848f9bccbe2cb89ce6de11de8422211beb0f;hpb=8731c5d9eb453a5b2d087dabd7a5f51b576b8048;p=p5sagit%2Fp5-mst-13.2.git

diff --git a/lib/base.pm b/lib/base.pm
index b735848..8bcbb5f 100644
--- a/lib/base.pm
+++ b/lib/base.pm
@@ -2,7 +2,7 @@ package base;
 
 use strict 'vars';
 use vars qw($VERSION);
-$VERSION = '2.04';
+$VERSION = '2.09';
 
 # constant.pm is slow
 sub SUCCESS () { 1 }
@@ -71,6 +71,10 @@ sub import {
     my $inheritor = caller(0);
 
     foreach my $base (@_) {
+        if ( $inheritor eq $base ) {
+            warn "Class '$inheritor' tried to inherit from itself\n";
+        }
+
         next if $inheritor->isa($base);
 
         if (has_version($base)) {
@@ -78,26 +82,31 @@ sub import {
 	      unless defined ${$base.'::VERSION'};
         }
         else {
-            local $SIG{__DIE__} = 'IGNORE';
-            eval "require $base";
-            # Only ignore "Can't locate" errors from our eval require.
-            # Other fatal errors (syntax etc) must be reported.
-            die if $@ && $@ !~ /^Can't locate .*? at \(eval /;
-            unless (%{"$base\::"}) {
-                require Carp;
-                Carp::croak(<<ERROR);
+	    my $sigdie;
+	    {
+		local $SIG{__DIE__};
+		eval "require $base";
+		# Only ignore "Can't locate" errors from our eval require.
+		# Other fatal errors (syntax etc) must be reported.
+		die if $@ && $@ !~ /^Can't locate .*? at \(eval /;
+		unless (%{"$base\::"}) {
+		    require Carp;
+		    Carp::croak(<<ERROR);
 Base class package "$base" is empty.
     (Perhaps you need to 'use' the module which defines that package first.)
 ERROR
-
-            }
+		}
+		$sigdie = $SIG{__DIE__};
+	    }
+	    # Make sure a global $SIG{__DIE__} makes it out of the localization.
+	    $SIG{__DIE__} = $sigdie if defined $sigdie;
             ${$base.'::VERSION'} = "-1, set by base.pm"
               unless defined ${$base.'::VERSION'};
         }
         push @{"$inheritor\::ISA"}, $base;
 
         if ( has_fields($base) || has_attr($base) ) {
-	    # No multiple fields inheritence *suck*
+	    # No multiple fields inheritance *suck*
 	    if ($fields_base) {
 		require Carp;
 		Carp::croak("Can't multiply inherit %FIELDS");
@@ -152,10 +161,9 @@ sub inherit_fields {
         }
     }
 
-    unless( keys %$bfields ) {
-        foreach my $idx (1..$#{$battr}) {
-            $dattr->[$idx] = $battr->[$idx] & INHERITED;
-        }
+    foreach my $idx (1..$#{$battr}) {
+	next if defined $dattr->[$idx];
+	$dattr->[$idx] = $battr->[$idx] & INHERITED;
     }
 }
 
@@ -193,15 +201,32 @@ it, <base> will define $VERSION in the base package, setting it to the string
 C<-1, set by base.pm>.
 
 Will also initialize the fields if one of the base classes has it.
-Multiple inheritence of fields is B<NOT> supported, if two or more
+Multiple inheritance of fields is B<NOT> supported, if two or more
 base classes each have inheritable fields the 'base' pragma will
 croak.  See L<fields>, L<public> and L<protected> for a description of
 this feature.
 
+=head1 DIAGNOSTICS
+
+=over 4
+
+=item Base class package "%s" is empty.
+
+base.pm was unable to require the base package, because it was not
+found in your path.
+
+=back
+
 =head1 HISTORY
 
 This module was introduced with Perl 5.004_04.
 
+Attempting to inherit from yourself generates a warning:
+
+ use Foo;
+ use base 'Foo';
+
+ # Class 'Foo' tried to inherit from itself
 
 =head1 CAVEATS