Improved parse error handling for CSSMQ.

Source/core/css/CSSGrammar.y.in

 /*
  *  Copyright (C) 2002-2003 Lars Knoll (knoll@kde.org)
  *  Copyright (C) 2004, 2005, 2006, 2007, 2008, 2009, 2010, 2011, 2012, 2013 Apple Inc. All rights reserved.
  *  Copyright (C) 2006 Alexey Proskuryakov (ap@nypop.com)
  *  Copyright (C) 2008 Eric Seidel <eric@webkit.org>
  *  Copyright (C) 2012 Intel Corporation. All rights reserved.
+ *  Copyright (C) 2013 Opera Software ASA. All rights reserved.
  *
  *  This library is free software; you can redistribute it and/or
  *  modify it under the terms of the GNU Lesser General Public
  *  License as published by the Free Software Foundation; either
  *  version 2 of the License, or (at your option) any later version.
  *
  *  This library is distributed in the hope that it will be useful,
  *  but WITHOUT ANY WARRANTY; without even the implied warranty of
  *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  *  Lesser General Public License for more details.
@@ skipping 63 matching lines @@
     case VAR_DEFINITION:
     case UNICODERANGE:
         return true;
     default:
         return false;
     }
 }
 
 %}
 
-%expect 38
+%expect 36
 
 %nonassoc LOWEST_PREC
 
 %left UNIMPORTANT_TOK
 
 %token WHITESPACE SGML_CD
 %token TOKEN_EOF 0
 
 %token INCLUDES
 %token DASHMATCH
@@ skipping 141 matching lines @@
 %type <string> namespace_selector
 
 %type <string> string_or_uri
 %type <string> ident_or_string
 %type <string> medium
 %type <marginBox> margin_sym
 
 %type <string> media_feature
 %type <mediaList> media_list
 %type <mediaList> maybe_media_list
-%type <mediaQuery> media_query
+%type <mediaQuery> media_query invalid_media_query
 %type <mediaQueryRestrictor> maybe_media_restrictor
 %type <valueList> maybe_media_value
 %type <mediaQueryExp> media_query_exp
 %type <mediaQueryExpList> media_query_exp_list
 %type <mediaQueryExpList> maybe_and_media_query_exp_list
 
 %type <boolean> supports_condition
 %type <boolean> supports_condition_in_parens
 %type <boolean> supports_negation
 %type <boolean> supports_conjunction
@@ skipping 91 matching lines @@
             parser->m_valueList = parser->sinkFloatingValueList($4);
             int oldParsedProperties = parser->m_parsedProperties.size();
             if (!parser->parseValue(parser->m_id, parser->m_important))
                 parser->rollbackLastProperties(parser->m_parsedProperties.size() - oldParsedProperties);
             parser->m_valueList = nullptr;
         }
     }
 ;
 
 webkit_mediaquery:
-     WEBKIT_MEDIAQUERY_SYM WHITESPACE maybe_space media_query '}' {
-         parser->m_mediaQuery = parser->sinkFloatingMediaQuery($4);
+     WEBKIT_MEDIAQUERY_SYM maybe_space media_query TOKEN_EOF {
+         parser->m_mediaQuery = parser->sinkFloatingMediaQuery($3);
+     }
+     | WEBKIT_MEDIAQUERY_SYM maybe_space media_query error TOKEN_EOF {
+         parser->m_mediaQuery = parser->sinkFloatingMediaQuery(parser->createFloatingMediaQuery(MediaQuery::Not, "all", parser->sinkFloatingMediaQueryExpList(parser->createFloatingMediaQueryExpList())));
+     }
+     | WEBKIT_MEDIAQUERY_SYM maybe_space error TOKEN_EOF {
+         parser->m_mediaQuery = parser->sinkFloatingMediaQuery(parser->createFloatingMediaQuery(MediaQuery::Not, "all", parser->sinkFloatingMediaQueryExpList(parser->createFloatingMediaQueryExpList())));
      }
 ;
 
 internal_selector:
     INTERNAL_SELECTOR_SYM '{' maybe_space selector_list '}' {
         if ($4) {
             if (parser->m_selectorListForParseSelector)
                 parser->m_selectorListForParseSelector->adoptSelectorVector(*$4);
         }
     }
@@ skipping 199 matching lines @@
 maybe_media_value:
     /*empty*/ {
         $$ = 0;
     }
     | ':' maybe_space expr maybe_space {
         $$ = $3;
     }
     ;
 
 media_query_exp:
-    maybe_media_restrictor maybe_space '(' maybe_space media_feature maybe_space maybe_media_value ')' maybe_space {
-        // If restrictor is specified, media query expression is invalid.
-        // Create empty media query expression and continue parsing media query.
-        if ($1 != MediaQuery::None)
-            $$ = parser->createFloatingMediaQueryExp("", 0);
-        else {
-            $5.lower();
-            $$ = parser->createFloatingMediaQueryExp($5, $7);
-        }
+    '(' maybe_space media_feature maybe_space maybe_media_value ')' maybe_space {
+        $3.lower();
+        $$ = parser->createFloatingMediaQueryExp($3, $5);
     }
     ;
 
 media_query_exp_list:
     media_query_exp {
         $$ = parser->createFloatingMediaQueryExpList();
         $$->append(parser->sinkFloatingMediaQueryExp($1));
     }
     | media_query_exp_list maybe_space MEDIA_AND maybe_space media_query_exp {
         $$ = $1;
@@ skipping 19 matching lines @@
     }
     | MEDIA_NOT {
         $$ = MediaQuery::Not;
     }
     ;
 
 media_query:
     media_query_exp_list {
         $$ = parser->createFloatingMediaQuery(parser->sinkFloatingMediaQueryExpList($1));
     }
-    |
-    maybe_media_restrictor maybe_space medium maybe_and_media_query_exp_list {
+    | maybe_media_restrictor maybe_space medium maybe_and_media_query_exp_list {
         $3.lower();
         $$ = parser->createFloatingMediaQuery($1, $3, parser->sinkFloatingMediaQueryExpList($4));
     }
+    | invalid_media_query maybe_space {
+        $$ = $1;
+    }
+    ;
+
+invalid_media_query:
+    error ',' {
+        $$ = parser->recoverMediaQuery();
+    }
+    | error '{' {
+        $$ = parser->recoverMediaQuery();
+    }
+    | error ';' {
+        $$ = parser->recoverMediaQuery();
+    }
+    | error '}' {
+        $$ = parser->recoverMediaQuery();
+    }
     ;
 
 maybe_media_list:
-     /* empty */ {
+    /* empty */ {
         $$ = parser->createMediaQuerySet();
-     }
-     | media_list
-     ;
+    }
+    | media_list
+    ;
+
+at_media_list_start:
+    /* empty */ {
+        parser->markMediaListStart();
+    }
+    ;
 
 media_list:
-    media_query {
+    at_media_list_start media_query {
         $$ = parser->createMediaQuerySet();
-        $$->addMediaQuery(parser->sinkFloatingMediaQuery($1));
+        $$->addMediaQuery(parser->sinkFloatingMediaQuery($2));
         parser->updateLastMediaLine($$);
     }
     | media_list ',' maybe_space media_query {
         $$ = $1;
-        if ($$) {
-            $$->addMediaQuery(parser->sinkFloatingMediaQuery($4));
-            parser->updateLastMediaLine($$);
-        }
+        $$->addMediaQuery(parser->sinkFloatingMediaQuery($4));
+        parser->updateLastMediaLine($$);
     }
-    | media_list error {
-        $$ = 0;
+    | media_list invalid_media_query maybe_space {
+        $$->replaceLastMediaQuery(parser->sinkFloatingMediaQuery($2));
     }
     ;
 
 at_rule_body_start:
     /* empty */ {
         parser->startRuleBody();
     }
     ;
 
 before_media_rule:
     /* empty */ {
         parser->startRuleHeader(CSSRuleSourceData::MEDIA_RULE);
     }
     ;
 
 at_rule_header_end_maybe_space:
     maybe_space {
         parser->endRuleHeader();
     }
     ;
 
 media:
     before_media_rule MEDIA_SYM maybe_space media_list at_rule_header_end '{' at_rule_body_start maybe_space block_rule_list save_block {
         $$ = parser->createMediaRule($4, $9);
     }
     | before_media_rule MEDIA_SYM at_rule_header_end_maybe_space '{' at_rule_body_start maybe_space block_rule_list save_block {
         $$ = parser->createMediaRule(0, $7);
     }
-    | before_media_rule MEDIA_SYM at_rule_header_end_maybe_space ';' {
+    | before_media_rule MEDIA_SYM maybe_space media_list at_rule_header_end ';' {
         $$ = 0;
         parser->endRuleBody(true);
     }
+    | before_media_rule MEDIA_SYM maybe_space media_list at_rule_header_end '}' {
+        $$ = 0;
+        parser->endRuleBody(true);
+    }
     ;
 
 medium:
   IDENT maybe_space {
       $$ = $1;
   }
   ;
 
 supports:
     before_supports_rule SUPPORTS_SYM maybe_space supports_condition at_supports_rule_header_end '{' at_rule_body_start maybe_space block_rule_list save_block {
@@ skipping 1306 matching lines @@
     }
     ;
 
 error_location: {
         $$ = parser->currentLocation();
     }
     ;
 
 %%