we no longer throw a violation if both regexes are modified in the sa…

…me way. This avoids violations for people who always append "smx" onto their regexes like good PBP followers.

We now throw violations for different uses of 's' modifier.
We do not throw violations for different uses of 'x' modifiers.

M    t/Bangs/ProhibitUselessRegexModifiers.run
M    lib/Perl/Critic/Policy/Bangs/ProhibitUselessRegexModifiers.pm

lib/Perl/Critic/Policy/Bangs/ProhibitUselessRegexModifiers.pm

@@ -29,31 +29,37 @@ sub violates {
     my ( $self, $elem, undef ) = @_;
 
 
-    # we throw a violation if both of two conditions are true:
+    # we throw a violation if all these conditions are true:
     # 1) there's an 'm' modifier
     # 2) the *only* thing in the regex is a compiled regex from a previous qr().
+    # 3) the modifiers are not the same in both places
     my %mods = get_modifiers($elem);
-    if ( $mods{'m'} ) {
+    if ( $mods{'m'} || $mods{'s'} ) {
         my $match = get_match_string( $elem );
         if ( $match =~ /^\$\w+$/smx ) {  # It looks like a single variable in there
-	  if ( _is_previously_assigned_quote_like_operator( $elem, $match ) ) {
-            return $self->violation( $DESC, $EXPL, $elem );
-	  }
+            if ( my $qr = _previously_assigned_quote_like_operator( $elem, $match ) ) {
+                # don't violate if both regexes are modified in the same way
+                if ( _sorted_modifiers( $elem ) ne _sorted_modifiers( $qr ) ) {
+                    return $self->violation( $DESC, $EXPL, $elem );
+                }
+            }
         }
     }
     return; #ok!;
 }
 
-sub _is_previously_assigned_quote_like_operator {
+sub _previously_assigned_quote_like_operator {
   my ( $elem, $match ) = @_;
 
   my $qlop = _find_previous_quote_like_regexp( $elem ) or return;
 
   # find if this previous quote-like-regexp assigned to the variable in $match
   my $parent = $qlop->parent();
-  my $found = $parent->find_any( sub { $_[1]->isa( 'PPI::Token::Symbol' ) and
-					 $_[1]->content eq $match } );
-  return $found;
+  if ( $parent->find_any( sub { $_[1]->isa( 'PPI::Token::Symbol' ) and
+                                  $_[1]->content eq $match } ) ) {
+      return $qlop;
+  }
+  return;
 }
 
 
@@ -68,6 +74,13 @@ sub _find_previous_quote_like_regexp {
     return $qlop;
 }
 
+sub _sorted_modifiers {
+    my $elem = shift;
+
+    my %mods = get_modifiers( $elem );
+    return join( '', sort keys %mods );
+}
+
 1;
 
 =pod

t/Bangs/ProhibitUselessRegexModifiers.run

@@ -40,11 +40,30 @@ if ( $string =~ /foo$regex/m ) {
 
 ## name Do not warn if the qr() is modified in the same way
 ## failures 0
-## TODO not handled yet
 ## cut
 
 my $regex = qr(asdf)m;
 if ( $string =~ /$regex/m ) {
 }
 
 #-----------------------------------------------------------------------------
+
+## name 's' modifier should fail
+## failures 1
+## cut
+
+my $regex = qr(asdf);
+if ( $string =~ /$regex/s ) {
+}
+
+#-----------------------------------------------------------------------------
+
+## name 'x' modifier should not trigger warning
+## failures 0
+## cut
+
+my $regex = qr(asdf);
+if ( $string =~ /$regex/x ) {
+}
+
+#-----------------------------------------------------------------------------