Item11780: ASSERT if expandCommon called in init

git-svn-id: http://svn.foswiki.org/branches/Release01x01@14644 0b4bb1d4-4e5a-0410-9cc4-b2b747904278

core/lib/Foswiki/Func.pm

@@ -2481,11 +2481,22 @@ Return: =$text=     Expanded text, e.g. ='Current user is <nop>WikiGuest'=
 
 See also: expandVariablesOnTopicCreation
 
+*Caution:* This function needs all the installed plugins to have gone through initialization.
+Never call this function from within an initPlugin handler,  bad things happen.
+
 =cut
 
 sub expandCommonVariables {
     my ( $text, $topic, $web, $meta ) = @_;
     ASSERT($Foswiki::Plugins::SESSION) if DEBUG;
+
+    if (DEBUG) {
+        for ( my $i = 4 ; $i <= 7 ; $i++ ) {
+            ASSERT( 0, "expandCommonVariables called during registration" )
+              if ( ( caller($i) )[3] eq 'Foswiki::Plugin::registerHandlers' );
+        }
+    }
+
     ( $web, $topic ) = _validateWTA(
         $web   || $Foswiki::Plugins::SESSION->{webName},
         $topic || $Foswiki::Plugins::SESSION->{topicName}