Plan 9 from Bell Labs’s /usr/web/sources/contrib/steve/root/sys/src/cmd/tidy/attrs.c

Copyright © 2021 Plan 9 Foundation.
Distributed under the MIT License.
Download the Plan 9 distribution.


/* attrs.c -- recognize HTML attributes

  (c) 1998-2001 (W3C) MIT, INRIA, Keio University
  See tidy.c for the copyright notice.
  
  CVS Info :

    $Author: creitzel $ 
    $Date: 2001/10/26 13:57:03 $ 
    $Revision: 1.39 $ 

*/

#include "platform.h"   /* platform independent stuff */
#include "html.h"       /* to pull in definition of nodes */

Attribute *attr_href;
Attribute *attr_src;
Attribute *attr_id;
Attribute *attr_name;
Attribute *attr_summary;
Attribute *attr_alt;
Attribute *attr_longdesc;
Attribute *attr_usemap;
Attribute *attr_ismap;
Attribute *attr_language;
Attribute *attr_type;
Attribute *attr_value;
Attribute *attr_content;
Attribute *attr_title;
Attribute *attr_xmlns;
Attribute *attr_datafld;
Attribute *attr_width;
Attribute *attr_height;

AttrCheck CheckUrl;
AttrCheck CheckScript;
AttrCheck CheckName;
AttrCheck CheckId;
AttrCheck CheckAlign;
AttrCheck CheckValign;
AttrCheck CheckBool;
AttrCheck CheckLength;
AttrCheck CheckTarget;
AttrCheck CheckFsubmit;
AttrCheck CheckClear;
AttrCheck CheckShape;
AttrCheck CheckNumber;
AttrCheck CheckScope;
AttrCheck CheckColor;
AttrCheck CheckVType;
AttrCheck CheckScroll;
AttrCheck CheckTextDir;
AttrCheck CheckLang;

extern Bool XmlTags;
extern Bool XmlOut;
extern char *alt_text;

#define XHTML_NAMESPACE "http://www.w3.org/1999/xhtml"

#define HASHSIZE 357

static Attribute *hashtab[HASHSIZE];

/*
 Bind attribute types to procedures to check values.
 You can add new procedures for better validation
 and each procedure has access to the node in which
 the attribute occurred as well as the attribute name
 and its value.

 By default, attributes are checked without regard
 to the element they are found on. You have the choice
 of making the procedure test which element is involved
 or in writing methods for each element which controls
 exactly how the attributes of that element are checked.
 This latter approach is best for detecting the absence
 of required attributes.
*/

#define TEXT        null
#define CHARSET     null
#define TYPE        null
#define CHARACTER   null
#define URLS        null
#define URL         CheckUrl
#define SCRIPT      CheckScript
#define ALIGN       CheckAlign
#define VALIGN      CheckValign
#define COLOR       CheckColor
#define CLEAR       CheckClear
#define BORDER      CheckBool     /* kludge */
#define LANG        CheckLang
#define BOOL        CheckBool
#define COLS        null
#define NUMBER      CheckNumber
#define LENGTH      CheckLength
#define COORDS      null
#define DATE        null
#define TEXTDIR     CheckTextDir
#define IDREFS      null
#define IDREF       null
#define IDDEF       CheckId
#define NAME        CheckName
#define TFRAME      null
#define FBORDER     null
#define MEDIA       null
#define FSUBMIT     CheckFsubmit
#define LINKTYPES   null
#define TRULES      null
#define SCOPE       CheckScope
#define SHAPE       CheckShape
#define SCROLL      CheckScroll
#define TARGET      CheckTarget
#define VTYPE       CheckVType

static struct _attrlist
{
    char *name;
    unsigned versions;
    AttrCheck *attrchk;
} attrlist[] =
{
    {"abbr",             VERS_HTML40,            TEXT},
    {"accept-charset",   VERS_HTML40,            CHARSET},
    {"accept",           VERS_ALL,               TYPE},
    {"accesskey",        VERS_HTML40,            CHARACTER},
    {"action",           VERS_ALL,               URL},
    {"add_date",         VERS_NETSCAPE,          TEXT},     /* A */
    {"align",            VERS_ALL,               ALIGN},    /* set varies with element */
    {"alink",            VERS_LOOSE,             COLOR},
    {"alt",              VERS_ALL,               TEXT},
    {"archive",          VERS_HTML40,            URLS},     /* space or comma separated list */
    {"axis",             VERS_HTML40,            TEXT},
    {"background",       VERS_LOOSE,             URL},
    {"bgcolor",          VERS_LOOSE,             COLOR},
    {"bgproperties",     VERS_PROPRIETARY,       TEXT},     /* BODY "fixed" fixes background */
    {"border",           VERS_ALL,               BORDER},   /* like LENGTH + "border" */
    {"bordercolor",      VERS_MICROSOFT,         COLOR},    /* used on TABLE */
    {"bottommargin",     VERS_MICROSOFT,         NUMBER},   /* used on BODY */
    {"cellpadding",      VERS_FROM32,            LENGTH},   /* % or pixel values */
    {"cellspacing",      VERS_FROM32,            LENGTH},
    {"char",             VERS_HTML40,            CHARACTER},
    {"charoff",          VERS_HTML40,            LENGTH},
    {"charset",          VERS_HTML40,            CHARSET},
    {"checked",          VERS_ALL,               BOOL},     /* i.e. "checked" or absent */
    {"cite",             VERS_HTML40,            URL},
    {"class",            VERS_HTML40,            TEXT},
    {"classid",          VERS_HTML40,            URL},
    {"clear",            VERS_LOOSE,             CLEAR},    /* BR: left, right, all */
    {"code",             VERS_LOOSE,             TEXT},     /* APPLET */
    {"codebase",         VERS_HTML40,            URL},      /* OBJECT */
    {"codetype",         VERS_HTML40,            TYPE},     /* OBJECT */
    {"color",            VERS_LOOSE,             COLOR},    /* BASEFONT, FONT */
    {"cols",             VERS_IFRAME,            COLS},     /* TABLE & FRAMESET */
    {"colspan",          VERS_FROM32,            NUMBER},
    {"compact",          VERS_ALL,               BOOL},     /* lists */
    {"content",          VERS_ALL,               TEXT},     /* META */
    {"coords",           VERS_FROM32,            COORDS},   /* AREA, A */    
    {"data",             VERS_HTML40,            URL},      /* OBJECT */
    {"datafld",          VERS_MICROSOFT,         TEXT},     /* used on DIV, IMG */
    {"dataformatas",     VERS_MICROSOFT,         TEXT},     /* used on DIV, IMG */
    {"datapagesize",     VERS_MICROSOFT,         NUMBER},   /* used on DIV, IMG */
    {"datasrc",          VERS_MICROSOFT,         URL},      /* used on TABLE */
    {"datetime",         VERS_HTML40,            DATE},     /* INS, DEL */
    {"declare",          VERS_HTML40,            BOOL},     /* OBJECT */
    {"defer",            VERS_HTML40,            BOOL},     /* SCRIPT */
    {"dir",              VERS_HTML40,            TEXTDIR},  /* ltr or rtl */
    {"disabled",         VERS_HTML40,            BOOL},     /* form fields */
    {"enctype",          VERS_ALL,               TYPE},     /* FORM */
    {"face",             VERS_LOOSE,             TEXT},     /* BASEFONT, FONT */
    {"for",              VERS_HTML40,            IDREF},    /* LABEL */
    {"frame",            VERS_HTML40,            TFRAME},   /* TABLE */
    {"frameborder",      VERS_FRAMESET,          FBORDER},  /* 0 or 1 */
    {"framespacing",     VERS_PROPRIETARY,       NUMBER},   /* pixel value */
    {"gridx",            VERS_PROPRIETARY,       NUMBER},   /* TABLE Adobe golive*/
    {"gridy",            VERS_PROPRIETARY,       NUMBER},   /* TABLE Adobe golive */
    {"headers",          VERS_HTML40,            IDREFS},   /* table cells */
    {"height",           VERS_ALL,               LENGTH},   /* pixels only for TH/TD */
    {"href",             VERS_ALL,               URL},      /* A, AREA, LINK and BASE */
    {"hreflang",         VERS_HTML40,            LANG},     /* A, LINK */
    {"hspace",           VERS_ALL,               NUMBER},   /* APPLET, IMG, OBJECT */
    {"http-equiv",       VERS_ALL,               TEXT},     /* META */
    {"id",               VERS_HTML40,            IDDEF},
    {"ismap",            VERS_ALL,               BOOL},     /* IMG */
    {"label",            VERS_HTML40,            TEXT},     /* OPT, OPTGROUP */
    {"lang",             VERS_HTML40,            LANG},
    {"language",         VERS_LOOSE,             TEXT},     /* SCRIPT */
    {"last_modified",    VERS_NETSCAPE,          TEXT},     /* A */
    {"last_visit",       VERS_NETSCAPE,          TEXT},     /* A */
    {"leftmargin",       VERS_MICROSOFT,         NUMBER},   /* used on BODY */
    {"link",             VERS_LOOSE,             COLOR},    /* BODY */
    {"longdesc",         VERS_HTML40,            URL},      /* IMG */
    {"lowsrc",           VERS_PROPRIETARY,       URL},      /* IMG */
    {"marginheight",     VERS_IFRAME,            NUMBER},   /* FRAME, IFRAME, BODY */
    {"marginwidth",      VERS_IFRAME,            NUMBER},   /* ditto */
    {"maxlength",        VERS_ALL,               NUMBER},   /* INPUT */
    {"media",            VERS_HTML40,            MEDIA},    /* STYLE, LINK */
    {"method",           VERS_ALL,               FSUBMIT},  /* FORM: get or post */
    {"multiple",         VERS_ALL,               BOOL},     /* SELECT */
    {"name",             VERS_ALL,               NAME},
    {"nohref",           VERS_FROM32,            BOOL},     /* AREA */
    {"noresize",         VERS_FRAMESET,          BOOL},     /* FRAME */
    {"noshade",          VERS_LOOSE,             BOOL},     /* HR */
    {"nowrap",           VERS_LOOSE,             BOOL},     /* table cells */
    {"object",           VERS_HTML40_LOOSE,      TEXT},     /* APPLET */
    {"onblur",           VERS_EVENTS,            SCRIPT},   /* event */
    {"onchange",         VERS_EVENTS,            SCRIPT},   /* event */
    {"onclick",          VERS_EVENTS,            SCRIPT},   /* event */
    {"ondblclick",       VERS_EVENTS,            SCRIPT},   /* event */
    {"onkeydown",        VERS_EVENTS,            SCRIPT},   /* event */
    {"onkeypress",       VERS_EVENTS,            SCRIPT},   /* event */
    {"onkeyup",          VERS_EVENTS,            SCRIPT},   /* event */
    {"onload",           VERS_EVENTS,            SCRIPT},   /* event */
    {"onmousedown",      VERS_EVENTS,            SCRIPT},   /* event */
    {"onmousemove",      VERS_EVENTS,            SCRIPT},   /* event */
    {"onmouseout",       VERS_EVENTS,            SCRIPT},   /* event */
    {"onmouseover",      VERS_EVENTS,            SCRIPT},   /* event */
    {"onmouseup",        VERS_EVENTS,            SCRIPT},   /* event */
    {"onsubmit",         VERS_EVENTS,            SCRIPT},   /* event */
    {"onreset",          VERS_EVENTS,            SCRIPT},   /* event */
    {"onselect",         VERS_EVENTS,            SCRIPT},   /* event */
    {"onunload",         VERS_EVENTS,            SCRIPT},   /* event */
    {"onfocus",          VERS_EVENTS,            SCRIPT},   /* event */
    {"onafterupdate",    VERS_MICROSOFT,         SCRIPT},   /* form fields */
    {"onbeforeupdate",   VERS_MICROSOFT,         SCRIPT},   /* form fields */
    {"onerrorupdate",    VERS_MICROSOFT,         SCRIPT},   /* form fields */
    {"onrowenter",       VERS_MICROSOFT,         SCRIPT},   /* form fields */
    {"onrowexit",        VERS_MICROSOFT,         SCRIPT},   /* form fields */
    {"onbeforeunload",   VERS_MICROSOFT,         SCRIPT},   /* form fields */
    {"ondatasetchanged", VERS_MICROSOFT,         SCRIPT},   /* object, applet */
    {"ondataavailable",  VERS_MICROSOFT,         SCRIPT},   /* object, applet */
    {"ondatasetcomplete",VERS_MICROSOFT,         SCRIPT},   /* object, applet */
    {"profile",          VERS_HTML40,            URL},      /* HEAD */
    {"prompt",           VERS_LOOSE,             TEXT},     /* ISINDEX */
    {"readonly",         VERS_HTML40,            BOOL},     /* form fields */
    {"rel",              VERS_ALL,               LINKTYPES}, /* A, LINK */
    {"rev",              VERS_ALL,               LINKTYPES}, /* A, LINK */
    {"rightmargin",      VERS_MICROSOFT,         NUMBER},   /* used on BODY */
    {"rows",             VERS_ALL,               NUMBER},   /* TEXTAREA */
    {"rowspan",          VERS_ALL,               NUMBER},   /* table cells */
    {"rules",            VERS_HTML40,            TRULES},   /* TABLE */
    {"scheme",           VERS_HTML40,            TEXT},     /* META */
    {"scope",            VERS_HTML40,            SCOPE},    /* table cells */
    {"scrolling",        VERS_IFRAME,            SCROLL},   /* yes, no or auto */
    {"selected",         VERS_ALL,               BOOL},     /* OPTION */
    {"shape",            VERS_FROM32,            SHAPE},    /* AREA, A */
    {"showgrid",         VERS_PROPRIETARY,       BOOL},     /* TABLE Adobe golive */
    {"showgridx",        VERS_PROPRIETARY,       BOOL},     /* TABLE Adobe golive*/
    {"showgridy",        VERS_PROPRIETARY,       BOOL},     /* TABLE Adobe golive*/
    {"size",             VERS_LOOSE,             NUMBER},   /* HR, FONT, BASEFONT, SELECT */
    {"span",             VERS_HTML40,            NUMBER},   /* COL, COLGROUP */
    {"src",              VERS_ALL,               URL},      /* IMG, FRAME, IFRAME */
    {"standby",          VERS_HTML40,            TEXT},     /* OBJECT */
    {"start",            VERS_ALL,               NUMBER},   /* OL */
    {"style",            VERS_HTML40,            TEXT},
    {"summary",          VERS_HTML40,            TEXT},     /* TABLE */
    {"tabindex",         VERS_HTML40,            NUMBER},   /* fields, OBJECT  and A */
    {"target",           VERS_HTML40,            TARGET},   /* names a frame/window */
    {"text",             VERS_LOOSE,             COLOR},    /* BODY */
    {"title",            VERS_HTML40,            TEXT},     /* text tool tip */
    {"topmargin",        VERS_MICROSOFT,         NUMBER},   /* used on BODY */
    {"type",             VERS_FROM32,            TYPE},     /* also used by SPACER */
    {"usemap",           VERS_ALL,               BOOL},     /* things with images */
    {"valign",           VERS_FROM32,            VALIGN},
    {"value",            VERS_ALL,               TEXT},     /* OPTION, PARAM */
    {"valuetype",        VERS_HTML40,            VTYPE},    /* PARAM: data, ref, object */
    {"version",          VERS_ALL,               TEXT},     /* HTML */
    {"vlink",            VERS_LOOSE,             COLOR},    /* BODY */
    {"vspace",           VERS_LOOSE,             NUMBER},   /* IMG, OBJECT, APPLET */
    {"width",            VERS_ALL,               LENGTH},   /* pixels only for TD/TH */
    {"wrap",             VERS_NETSCAPE,          TEXT},     /* textarea */
    {"xml:lang",         VERS_XML,               TEXT},     /* XML language */
    {"xml:space",        VERS_XML,               TEXT},     /* XML language */
    {"xmlns",            VERS_ALL,               TEXT},     /* name space */
    {"rbspan",           VERS_XHTML11,           NUMBER},   /* ruby markup */
   
   /* this must be the final entry */
    {null,               0,                      0}
};

/* used by CheckColor() */
static struct _colors
{
    char *name;
    char *hex;
} colors[] =
{
    {"black",   "#000000"}, {"green",  "#008000"},
    {"silver",  "#C0C0C0"}, {"lime",   "#00FF00"},
    {"gray",    "#808080"}, {"olive",  "#808000"},
    {"white",   "#FFFFFF"}, {"yellow", "#FFFF00"},
    {"maroon",  "#800000"}, {"navy",   "#000080"},
    {"red",     "#FF0000"}, {"blue",   "#0000FF"},
    {"purple",  "#800080"}, {"teal",   "#008080"},
    {"fuchsia", "#FF00FF"}, {"aqua",   "#00FFFF"},
    {null,      null}
};

static unsigned hash(char *s)
{
    unsigned hashval;

    for (hashval = 0; *s != '\0'; s++)
        hashval = *s + 31*hashval;

    return hashval % HASHSIZE;
}

static Attribute *lookup(char *s)
{
    Attribute *np;

    for (np = hashtab[hash(s)]; np != null; np = np->next)
        if (wstrcmp(s, np->name) == 0)
            return np;
    return null;
}

static Attribute *install(char *name, uint versions, AttrCheck *attrchk)
{
    Attribute *np;
    unsigned hashval;

    if ((np = lookup(name)) == null)
    {
        np = (Attribute *)MemAlloc(sizeof(*np));

        if (np == null || (np->name = wstrdup(name)) == null)
            return null;

        hashval = hash(name);
        np->next = hashtab[hashval];
        hashtab[hashval] = np;
    }

    np->versions = versions;
    np->attrchk = attrchk;
    np->nowrap = no;
    np->literal = no;
    return np;
}

static void SetNoWrap(Attribute *attr)
{
    attr->nowrap = yes;  /* defaults to no */
}

/* public method for finding attribute definition by name */
Attribute *FindAttribute(AttVal *attval)
{
    Attribute *np;

    if (attval->attribute && (np = lookup(attval->attribute)))
        return np;

    return null;
}

AttVal *GetAttrByName(Node *node, char *name)
{
    AttVal *attr;

    for (attr = node->attributes; attr != null; attr = attr->next)
    {
        if (wstrcmp(attr->attribute, name) == 0)
            break;
    }

    return attr;
}

void AddAttribute(Node *node, char *name, char *value)
{
    AttVal *av = NewAttribute();
    av->delim = '"';
    av->attribute = wstrdup(name);
    av->value = wstrdup(value);
    av->dict = FindAttribute(av);

    if (node->attributes == null)
        node->attributes = av;
    else /* append to end of attributes */
    {
        AttVal *here = node->attributes;

        while (here->next)
            here = here->next;

        here->next = av;
    }
}

Bool IsUrl(char *attrname)
{
    Attribute *np;

    return (Bool)((np = lookup(attrname)) && np->attrchk == URL);
}

Bool IsBool(char *attrname)
{
    Attribute *np;

    return (Bool)((np = lookup(attrname)) && np->attrchk == BOOL);
}

Bool IsScript(char *attrname)
{
    Attribute *np;

    return (Bool)((np = lookup(attrname)) && np->attrchk == SCRIPT);
}

Bool IsLiteralAttribute(char *attrname)
{
    Attribute *np;

    return (Bool)((np = lookup(attrname)) && np->literal);
}

/* may id or name serve as anchor? */
Bool IsAnchorElement(Node *node)
{
    if (node->tag == tag_a      ||
        node->tag == tag_applet ||
        node->tag == tag_form   ||
        node->tag == tag_frame  ||
        node->tag == tag_iframe ||
        node->tag == tag_img    ||
        node->tag == tag_map)
        return yes;

    return no;
}

/* anchor/node hash */

Anchor *anchor_list = null;

/* free single anchor */
void FreeAnchor(Anchor *a)
{
    if (a->name)
        MemFree(a->name);

    MemFree(a);
}

/* removes anchor for specific node */
void RemoveAnchorByNode(Node *node)
{
    Anchor *delme = null, *found, *prev = null, *next;

    for (found = anchor_list; found != null; found = found->next)
    {
        next = found->next;

        if (found->node == node)
        {
            if (prev)
                prev->next = next;
            else
                anchor_list = next;

            delme = found;
        }
        else
            prev = found;
    }
    if (delme)
        FreeAnchor(delme);
}

/* initialize new anchor */
Anchor *NewAnchor(void)
{
    Anchor *a = (Anchor *)MemAlloc(sizeof(Anchor));

    a->name = null;
    a->next = null;
    a->node = null;

    return a;
}

/* add new anchor to namespace */
Anchor *AddAnchor(char *name, Node *node)
{
    Anchor *a = NewAnchor();

    a->name = wstrdup(name);
    a->node = node;

    if (anchor_list == null)
        anchor_list = a;
    else
    {
        Anchor *here = anchor_list;

        while (here->next)
            here = here->next;

        here->next = a;
    }

    return anchor_list;
}

/* return node associated with anchor */
Node *GetNodeByAnchor(char *name)
{
    Anchor *found;
    
    for (found = anchor_list; found != null; found = found->next)
    {
        if (wstrcasecmp(found->name, name) == 0)
            break;
    }
    
    if (found == null)
        return null;
    else
        return found->node;
}

/* free all anchors */
void FreeAnchors(void)
{
    Anchor *a;
    
    while (anchor_list)
    {
        a = anchor_list;
        
        if (a->name)
            MemFree(a->name);
        
        anchor_list = a->next;
        MemFree(a);
    }
}

/* public method for inititializing attribute dictionary */
void InitAttrs(void)
{
    struct _attrlist *ap;
    
    for(ap = attrlist; ap->name != null; ++ap)
        install(ap->name, ap->versions, ap->attrchk);

    attr_href = lookup("href");
    attr_src = lookup("src");
    attr_id = lookup("id");
    attr_name = lookup("name");
    attr_summary = lookup("summary");
    attr_alt = lookup("alt");
    attr_longdesc = lookup("longdesc");
    attr_usemap = lookup("usemap");
    attr_ismap = lookup("ismap");
    attr_language = lookup("language");
    attr_type = lookup("type");
    attr_title = lookup("title");
    attr_xmlns = lookup("xmlns");
    attr_datafld = lookup("datafld");
    attr_value = lookup("value");
    attr_content = lookup("content");
    attr_width = lookup("width");
    attr_height = lookup("height");

    SetNoWrap(attr_alt);
    SetNoWrap(attr_value);
    SetNoWrap(attr_content);
}

/*
Henry Zrepa reports that some folk are
using embed with script attributes where
newlines are signficant. These need to be
declared and handled specially!
*/
void DeclareLiteralAttrib(char *name)
{
    Attribute *attrib = lookup(name);

    if (attrib == null) /* #431337 - fix by Terry Teague 07 Jun 01 */
        attrib = install(name, VERS_PROPRIETARY, null);

    attrib->literal = yes;
}

void FreeAttrTable(void)
{
    Attribute *dict, *next;
    int i;

    for (i = 0; i < HASHSIZE; ++i)
    {
        dict = hashtab[i];

        while(dict)
        {
            next = dict->next;
            MemFree(dict->name);
            MemFree(dict);
            dict = next;
        }

        hashtab[i] = null;
    }

    FreeAnchors();
}

/*
 the same attribute name can't be used
 more than once in each element
*/

void RepairDuplicateAttributes(Lexer *lexer, Node *node)
{
    AttVal *attval;

    for (attval = node->attributes; attval != null;)
    {
        if (attval->asp == null && attval->php == null)
        {
            AttVal *current;
            
            for (current = attval->next; current != null;)
            {
                if (current->asp == null && current->php == null &&
                    wstrcasecmp(attval->attribute, current->attribute) == 0)
                {
                    AttVal *temp;

                    if (wstrcasecmp(current->attribute, "class") == 0 && JoinClasses)
                    {
                        /* concatenate classes */

                        current->value = (char *)MemRealloc(current->value, wstrlen(current->value) +
                                                                            wstrlen(attval->value)  + 2);
                        wstrcat(current->value, " ");
                        wstrcat(current->value, attval->value);

                        temp = attval->next;

                        if (temp->next == null)
                            current = null;
                        else
                            current = current->next;

                        ReportAttrError(lexer, node, attval, JOINING_ATTRIBUTE);

                        RemoveAttribute(node, attval);
                        attval = temp;
                    }
                    else if (wstrcasecmp(current->attribute, "style") == 0 && JoinStyles)
                    {
                        /* concatenate styles */

                        /*
                          this doesn't handle CSS comments and
                          leading/trailing white-space very well
                          see http://www.w3.org/TR/css-style-attr
                        */

                        size_t end = strlen(current->value);

                        if (current->value[end] == ';')
                        {
                            /* attribute ends with declaration seperator */

                            current->value = (char *)MemRealloc(current->value,
                                end + wstrlen(attval->value) + 2);

                            wstrcat(current->value, " ");
                            wstrcat(current->value, attval->value);
                        }
                        else if (current->value[end] == '}')
                        {
                            /* attribute ends with rule set */

                            current->value = (char *)MemRealloc(current->value,
                                end + wstrlen(attval->value) + 6);

                            wstrcat(current->value, " { ");
                            wstrcat(current->value, attval->value);
                            wstrcat(current->value, " }");
                        }
                        else
                        {
                            /* attribute ends with property value */

                            current->value = (char *)MemRealloc(current->value,
                                end + wstrlen(attval->value) + 3);

                            wstrcat(current->value, "; ");
                            wstrcat(current->value, attval->value);
                        }

                        temp = attval->next;

                        if (temp->next == null)
                            current = null;
                        else
                            current = current->next;

                        ReportAttrError(lexer, node, attval, JOINING_ATTRIBUTE);

                        RemoveAttribute(node, attval);
                        attval = temp;

                    }
                    else if (DuplicateAttrs == keep_last)
                    {
                        temp = current->next;

                        ReportAttrError(lexer, node, current, REPEATED_ATTRIBUTE);
                        
                        RemoveAttribute(node, current);
                        current = temp;
                    }
                    else
                    {
                        temp = attval->next;

                        if (attval->next == null)
                            current = null;
                        else
                            current = current->next;

                        ReportAttrError(lexer, node, attval, REPEATED_ATTRIBUTE);

                        RemoveAttribute(node, attval);
                        attval = temp;
                    }
                }
                else
                    current = current->next;
            }
            attval = attval->next;
        }
        else
            attval = attval->next;
    }
}


/* ignore unknown attributes for proprietary elements */
Attribute *CheckAttribute(Lexer *lexer, Node *node, AttVal *attval)
{
    Attribute *attribute;

    if ((attribute = attval->dict) != null)
    {
        /* if attribute looks like <foo/> check XML is ok */
        if (attribute->versions & VERS_XML)
        {
            if (!(XmlTags || XmlOut))
                ReportAttrError(lexer, node, attval, XML_ATTRIBUTE_VALUE);
        } /* title first appeared in HTML 4.0 except for a/link */
        else if (attribute != attr_title ||
                    !(node->tag == tag_a || node->tag == tag_link))
            ConstrainVersion(lexer, attribute->versions);
        
        if (attribute->attrchk)
            attribute->attrchk(lexer, node, attval);
        else if (attval->dict->versions & VERS_PROPRIETARY)
            ReportAttrError(lexer, node, attval, PROPRIETARY_ATTRIBUTE);
    }
    else if (!XmlTags && !(node->tag == null) && attval->asp == null &&
             !(node->tag && (node->tag->versions & VERS_PROPRIETARY)))
        ReportAttrError(lexer, node, attval, UNKNOWN_ATTRIBUTE);

    return attribute;
}

Bool IsBoolAttribute(AttVal *attval)
{
    Attribute *attribute;

    if ((attribute = attval->dict) != null)
    {
        if (attribute->attrchk == CheckBool)
            return yes;
    }

    return no;
}

/* methods for checking value of a specific attribute */

void CheckUrl(Lexer *lexer, Node *node, AttVal *attval)
{
    char c, *dest, *p;
    uint escape_count = 0, backslash_count = 0;
    uint i, pos = 0;
    size_t len;
    
    if (attval == null || attval->value == null)
    {
        ReportAttrError(lexer, node, attval, MISSING_ATTR_VALUE);
        return;
    }

    p = attval->value;
    
    for (i = 0; c = p[i]; ++i)
    {
        if (c == '\\')
        {
            ++backslash_count;
            if (FixBackslash)
                p[i] = '/';
        }
        else if ((c > 0x7e) || (c <= 0x20) || (strchr("<>", c)))
            ++escape_count;
    }
    
    if (FixUri && escape_count)
    {
        len = wstrlen(p) + escape_count * 2 + 1;
        dest = (char *)MemAlloc(len);
        
        for (i = 0; c = p[i]; ++i)
        {
            if ((c > 0x7e) || (c <= 0x20) || (strchr("<>", c)))
                pos += sprintf(dest + pos, "%%%02X", (unsigned char)c);
            else
                dest[pos++] = c;
        }
        dest[pos++] = 0;

        MemFree(attval->value);
        attval->value = dest;
    }
    if (backslash_count)
    {
        if (FixBackslash)
            ReportAttrError(lexer, node, attval, FIXED_BACKSLASH);
        else
            ReportAttrError(lexer, node, attval, BACKSLASH_IN_URI);
    }
    if (escape_count)
    {
        if (FixUri)
            ReportAttrError(lexer, node, attval, ESCAPED_ILLEGAL_URI);
        else
            ReportAttrError(lexer, node, attval, ILLEGAL_URI_REFERENCE);

        lexer->badChars |= INVALID_URI;
    }
}

void CheckScript(Lexer *lexer, Node *node, AttVal *attval)
{
}

void CheckName(Lexer *lexer, Node *node, AttVal *attval)
{
    Node *old;

    if (attval == null || attval->value == null)
    {
        ReportAttrError(lexer, node, attval, MISSING_ATTR_VALUE);
        return;
    }

    if (IsAnchorElement(node))
    {
        ConstrainVersion(lexer, ~VERS_XHTML11);

        if ((old = GetNodeByAnchor(attval->value)) &&  old != node)
        {
            ReportAttrError(lexer, node, attval, ANCHOR_NOT_UNIQUE);
        }
        else
            anchor_list = AddAnchor(attval->value, node);
    }
}

void CheckId(Lexer *lexer, Node *node, AttVal *attval)
{
    char *p;
    Node *old;
    
    if (attval == null || attval->value == null)
    {
        ReportAttrError(lexer, node, attval, MISSING_ATTR_VALUE);
        return;
    }

    p = attval->value;
    
    if (!IsLetter(*p++))
    {
        ReportAttrError(lexer, node, attval, BAD_ATTRIBUTE_VALUE);
    } else {

        while(*p)
        {
            if (!IsNamechar(*p++))
            {
                ReportAttrError(lexer, node, attval, BAD_ATTRIBUTE_VALUE);
                break;
            }
        }
    }

    if ((old = GetNodeByAnchor(attval->value)) &&  old != node)
    {
        ReportAttrError(lexer, node, attval, ANCHOR_NOT_UNIQUE);
    }
    else
        anchor_list = AddAnchor(attval->value, node);
}

void CheckBool(Lexer *lexer, Node *node, AttVal *attval)
{
    if (attval == null || attval->value == null)
        return;

    if (LowerLiterals)
        attval->value = wstrtolower(attval->value);
}

void CheckAlign(Lexer *lexer, Node *node, AttVal *attval)
{
    char *value;

    /* IMG, OBJECT, APPLET and EMBED use align for vertical position */
    if (node->tag && (node->tag->model & CM_IMG))
    {
        CheckValign(lexer, node, attval);
        return;
    }

    if (attval == null || attval->value == null)
    {
        ReportAttrError(lexer, node, attval, MISSING_ATTR_VALUE);
        return;
    }

    if (LowerLiterals)
        attval->value = wstrtolower(attval->value);

    value = attval->value;

    if (! (wstrcasecmp(value,    "left") == 0 ||
           wstrcasecmp(value,  "center") == 0 ||
           wstrcasecmp(value,   "right") == 0 ||
           wstrcasecmp(value, "justify") == 0))
        ReportAttrError(lexer, node, attval, BAD_ATTRIBUTE_VALUE);
}

void CheckValign(Lexer *lexer, Node *node, AttVal *attval)
{
    char *value;

    if (attval == null || attval->value == null)
    {
        ReportAttrError(lexer, node, attval, MISSING_ATTR_VALUE);
        return;
    }

    if (LowerLiterals)
        attval->value = wstrtolower(attval->value);

    value = attval->value;

    if (wstrcasecmp(value,      "top") == 0 ||
        wstrcasecmp(value,   "middle") == 0 ||
        wstrcasecmp(value,   "bottom") == 0 ||
        wstrcasecmp(value, "baseline") == 0)
    {
            /* all is fine */
    }
    else if (wstrcasecmp(value,  "left") == 0 ||
             wstrcasecmp(value, "right") == 0)
    {
        if (!(node->tag && (node->tag->model & CM_IMG)))
            ReportAttrError(lexer, node, attval, BAD_ATTRIBUTE_VALUE);
    }
    else if (wstrcasecmp(value,    "texttop") == 0 ||
             wstrcasecmp(value,  "absmiddle") == 0 ||
             wstrcasecmp(value,  "absbottom") == 0 ||
             wstrcasecmp(value, "textbottom") == 0)
    {
        ConstrainVersion(lexer, VERS_PROPRIETARY);
        ReportAttrError(lexer, node, attval, PROPRIETARY_ATTR_VALUE);
    }
    else
        ReportAttrError(lexer, node, attval, BAD_ATTRIBUTE_VALUE);
}

void CheckLength(Lexer *lexer, Node *node, AttVal *attval)
{
    char *p;
    
    if (attval == null || attval->value == null)
    {
        ReportAttrError(lexer, node, attval, MISSING_ATTR_VALUE);
        return;
    }

    p = attval->value;
    
    if (!IsDigit(*p++))
    {
        ReportAttrError(lexer, node, attval, BAD_ATTRIBUTE_VALUE);
    } else {

        while (*p)
        {
            if (!IsDigit(*p) && *p != '%')
            {
                ReportAttrError(lexer, node, attval, BAD_ATTRIBUTE_VALUE);
                break;
            }
            ++p;
        }
    }
}

void CheckTarget(Lexer *lexer, Node *node, AttVal *attval)
{
    char *value;
    
    if (attval == null || attval->value == null)
    {
        ReportAttrError(lexer, node, attval, MISSING_ATTR_VALUE);
        return;
    }

    /*
      target names must begin with A-Za-z or be one of
      _blank, _self, _parent and _top
    */
    
    value = attval->value;

    if (IsLetter(value[0]))
        return;
    
    if (! (wstrcasecmp(value,  "_blank") == 0 ||
           wstrcasecmp(value,   "_self") == 0 ||
           wstrcasecmp(value, "_parent") == 0 ||
           wstrcasecmp(value,    "_top") == 0))
        ReportAttrError(lexer, node, attval, BAD_ATTRIBUTE_VALUE);
}

void CheckFsubmit(Lexer *lexer, Node *node, AttVal *attval)
{
    char *value;
    
    if (attval == null || attval->value == null)
    {
        ReportAttrError(lexer, node, attval, MISSING_ATTR_VALUE);
        return;
    }

    value = attval->value;

    if (LowerLiterals)
        attval->value = wstrtolower(attval->value);

    if (! (wstrcasecmp(value,  "get") == 0 ||
           wstrcasecmp(value, "post") == 0))
        ReportAttrError(lexer, node, attval, BAD_ATTRIBUTE_VALUE);
}

void CheckClear(Lexer *lexer, Node *node, AttVal *attval)
{
    char *value;

    if (attval == null || attval->value == null)
    {
        ReportAttrError(lexer, node, attval, MISSING_ATTR_VALUE);
        return;
    }

    if (LowerLiterals)
        attval->value = wstrtolower(attval->value);
        
    value = attval->value;
    
    if (! (wstrcasecmp(value,  "none") == 0 ||
           wstrcasecmp(value,  "left") == 0 ||
           wstrcasecmp(value, "right") == 0 ||
           wstrcasecmp(value,   "all") == 0))
        ReportAttrError(lexer, node, attval, BAD_ATTRIBUTE_VALUE);
}

void CheckShape(Lexer *lexer, Node *node, AttVal *attval)
{
    char *value;
    
    if (attval == null || attval->value == null)
    {
        ReportAttrError(lexer, node, attval, MISSING_ATTR_VALUE);
        return;
    }

    if (LowerLiterals)
        attval->value = wstrtolower(attval->value);

    value = attval->value;
    
    if (! (wstrcasecmp(value,    "rect") == 0 ||
           wstrcasecmp(value, "default") == 0 ||
           wstrcasecmp(value,  "circle") == 0 ||
           wstrcasecmp(value,    "poly") == 0))
        ReportAttrError(lexer, node, attval, BAD_ATTRIBUTE_VALUE);
}

void CheckScope(Lexer *lexer, Node *node, AttVal *attval)
{
    char *value;
    
    if (attval == null || attval->value == null)
    {
        ReportAttrError(lexer, node, attval, MISSING_ATTR_VALUE);
        return;
    }

    if (LowerLiterals)
        attval->value = wstrtolower(attval->value);

    value = attval->value;
    
    if (! (wstrcasecmp(value,      "row") == 0 ||
           wstrcasecmp(value, "rowgroup") == 0 ||
           wstrcasecmp(value,      "col") == 0 ||
           wstrcasecmp(value, "colgroup") == 0))
        ReportAttrError(lexer, node, attval, BAD_ATTRIBUTE_VALUE);
}

void CheckNumber(Lexer *lexer, Node *node, AttVal *attval)
{
    char *p;
    
    if (attval == null || attval->value == null)
    {
        ReportAttrError(lexer, node, attval, MISSING_ATTR_VALUE);
        return;
    }

    p  = attval->value;
    
    /* font size may be preceded by + or - */
    if (node->tag == tag_font && (*p == '+' || *p == '-'))
        ++p;

    while (*p)
    {
        if (!IsDigit(*p))
        {
            ReportAttrError(lexer, node, attval, BAD_ATTRIBUTE_VALUE);
            break;
        }
        ++p;
    }
}

/* check color syntax and beautify value by option */
void CheckColor(Lexer *lexer, Node *node, AttVal *attval)
{
    Bool ReplaceColor = yes;
    Bool HexUppercase = yes;
    Bool invalid = no;
    Bool found = no;
    char *given;
    struct _colors *color;
    uint i = 0;

    if (attval == null || attval->value == null)
    {
        ReportAttrError(lexer, node, attval, MISSING_ATTR_VALUE);
        return;
    }

    given = attval->value;
    
    for (color = colors; color->name; ++color)
    {
        if (given[0] == '#')
        {
            if (wstrlen(given) != 7)
            {
                ReportAttrError(lexer, node, attval, BAD_ATTRIBUTE_VALUE);
                invalid = yes;
                break;
            }
            else if (wstrcasecmp(given, color->hex) == 0)
            {
                if (ReplaceColor)
                {
                    MemFree(attval->value);
                    attval->value = wstrdup(color->name);
                }
                found = yes;
                break;
            }
        }
        else if (IsLetter(given[0]))
        {
            if (wstrcasecmp(given, color->name) == 0)
            {
                if (ReplaceColor)
                {
                    MemFree(attval->value);
                    attval->value = wstrdup(color->name);
                }
                found = yes;
                break;
            }
        }
        else
        {
            ReportAttrError(lexer, node, attval, BAD_ATTRIBUTE_VALUE);
            invalid = yes;
            break;
        }
    }
    
    if (!found && !invalid)
    {
        if (given[0] == '#')
        {
            /* check if valid hex digits and letters */
            for (i = 1; i < 7; ++i)
            {
                if (!IsDigit(given[i]) &&
                    !strchr("abcdef", ToLower(given[i])))
                {
                    ReportAttrError(lexer, node, attval, BAD_ATTRIBUTE_VALUE);
                    invalid = yes;
                    break;
                }
            }
            
            /* convert hex letters to uppercase */
            if (!invalid && HexUppercase)
            {
                for (i = 1; i < 7; ++i)
                {
                    given[i] = ToUpper(given[i]);
                }
            }
        }
        else
        {
            /* we could search for more colors and mark the file as HTML
               Proprietary, but I don't thinks it's worth the effort,
               so values not in HTML 4.01 are invalid */

            ReportAttrError(lexer, node, attval, BAD_ATTRIBUTE_VALUE);
        }
    }
}

/* check valuetype attribute for element param */
void CheckVType(Lexer *lexer, Node *node, AttVal *attval)
{
    char *value;

    if (attval == null || attval->value == null)
    {
        ReportAttrError(lexer, node, attval, MISSING_ATTR_VALUE);
        return;
    }

    if (LowerLiterals)
        attval->value = wstrtolower(attval->value);

    value = attval->value;

    if (! (wstrcasecmp(value,   "data") == 0 ||
           wstrcasecmp(value, "object") == 0 ||
           wstrcasecmp(value,    "ref") == 0))
        ReportAttrError(lexer, node, attval, BAD_ATTRIBUTE_VALUE);
}

/* checks scrolling attribute */
void CheckScroll(Lexer *lexer, Node *node, AttVal *attval)
{
    char *value;

    if (attval == null || attval->value == null)
    {
        ReportAttrError(lexer, node, attval, MISSING_ATTR_VALUE);
        return;
    }

    if (LowerLiterals)
        attval->value = wstrtolower(attval->value);

    value = attval->value;

    if (! (wstrcasecmp(value,   "no") == 0 ||
           wstrcasecmp(value, "auto") == 0 ||
           wstrcasecmp(value,  "yes") == 0))
        ReportAttrError(lexer, node, attval, BAD_ATTRIBUTE_VALUE);
}

/* checks dir attribute */
void CheckTextDir(Lexer *lexer, Node *node, AttVal *attval)
{
    char *value;

    if (attval == null || attval->value == null)
    {
        ReportAttrError(lexer, node, attval, MISSING_ATTR_VALUE);
        return;
    }

    if (LowerLiterals)
        attval->value = wstrtolower(attval->value);

    value = attval->value;

    if (! (wstrcasecmp(value, "rtl") == 0 ||
           wstrcasecmp(value, "ltr") == 0))
        ReportAttrError(lexer, node, attval, BAD_ATTRIBUTE_VALUE);
}

/* checks lang and xml:lang attributes */
void CheckLang(Lexer *lexer, Node *node, AttVal *attval)
{
    if (attval == null || attval->value == null)
    {
        ReportAttrError(lexer, node, attval, MISSING_ATTR_VALUE);
        return;
    }

    if (wstrcasecmp(attval->attribute, "lang") == 0)
        ConstrainVersion(lexer, ~VERS_XHTML11);
}

/* default method for checking an element's attributes */
void CheckAttributes(Lexer *lexer, Node *node)
{
    AttVal *attval;

    for (attval = node->attributes; attval != null; attval = attval->next)
        CheckAttribute(lexer, node, attval);
}

/* methods for checking attributes for specific elements */

void CheckHR(Lexer *lexer, Node *node)
{
    AttVal *av = GetAttrByName(node, "src");

    CheckAttributes(lexer, node);

    if (av)
        ReportAttrError(lexer, node, av, PROPRIETARY_ATTR_VALUE);
}

void CheckIMG(Lexer *lexer, Node *node)
{
    AttVal *attval;
    Attribute *attribute;
    Bool HasAlt = no;
    Bool HasSrc = no;
    Bool HasUseMap = no;
    Bool HasIsMap = no;
    Bool HasDataFld = no;

    for (attval = node->attributes; attval != null; attval = attval->next)
    {
        attribute = CheckAttribute(lexer, node, attval);

        if (attribute == attr_alt)
            HasAlt = yes;
        else if (attribute == attr_src)
            HasSrc = yes;
        else if (attribute == attr_usemap)
            HasUseMap = yes;
        else if (attribute == attr_ismap)
            HasIsMap = yes;
        else if (attribute == attr_datafld)
            HasDataFld = yes;
        else if (attribute == attr_width || attribute == attr_height)
            ConstrainVersion(lexer, ~VERS_HTML20);
    }

    if (!HasAlt)
    {
        lexer->badAccess |= MISSING_IMAGE_ALT;
        ReportMissingAttr(lexer, node, "alt");

        if (alt_text)
            AddAttribute(node, "alt", alt_text);
    }

    if (!HasSrc && !HasDataFld)
        ReportMissingAttr(lexer, node, "src");

    if (HasIsMap && !HasUseMap)
        ReportMissingAttr(lexer, node, "ismap");
}

void CheckAnchor(Lexer *lexer, Node *node)
{
    CheckAttributes(lexer, node);

    FixId(lexer, node);
}

void CheckMap(Lexer *lexer, Node *node)
{
    CheckAttributes(lexer, node);

    FixId(lexer, node);
}

void CheckTableCell(Lexer *lexer, Node *node)
{
    CheckAttributes(lexer, node);

    /*
      HTML4 strict doesn't allow mixed content for
      elements with %block; as their content model
    */
    if (GetAttrByName(node, "width") || GetAttrByName(node, "height"))
        ConstrainVersion(lexer, ~VERS_HTML40_STRICT);
}

void CheckCaption(Lexer *lexer, Node *node)
{
    AttVal *attval;
    char *value = null;

    CheckAttributes(lexer, node);

    for (attval = node->attributes; attval != null; attval = attval->next)
    {
        if (wstrcasecmp(attval->attribute, "align") == 0)
        {
            value = attval->value;
            break;
        }
    }

    if (value != null)
    {
        if (wstrcasecmp(value, "left") == 0 || wstrcasecmp(value, "right") == 0)
            ConstrainVersion(lexer, VERS_HTML40_LOOSE);
        else if (wstrcasecmp(value, "top") == 0 || wstrcasecmp(value, "bottom") == 0)
            ConstrainVersion(lexer, ~(VERS_HTML20|VERS_HTML32));
        else
            ReportAttrError(lexer, node, attval, BAD_ATTRIBUTE_VALUE);
    }
}

void CheckHTML(Lexer *lexer, Node *node)
{
    AttVal *attval;
    Attribute *attribute;

    for (attval = node->attributes; attval != null; attval = attval->next)
    {
        attribute = CheckAttribute(lexer, node, attval);
        if (attribute == attr_xmlns && wstrcmp(attval->value, XHTML_NAMESPACE)==0 )
        {
            lexer->isvoyager = yes;
            if ( ! HtmlOut )  /* Unless user has specified plain HTML output, */
              xHTML = yes;    /* output format will be XHTML. */
        }
    }
}

void CheckAREA(Lexer *lexer, Node *node)
{
    AttVal *attval;
    Attribute *attribute;
    Bool HasAlt = no;
    Bool HasHref = no;

    for (attval = node->attributes; attval != null; attval = attval->next)
    {
        attribute = CheckAttribute(lexer, node, attval);

        if (attribute == attr_alt)
            HasAlt = yes;
        else if (attribute == attr_href)
            HasHref = yes;
    }

    if (!HasAlt)
    {
        lexer->badAccess |= MISSING_LINK_ALT;
        ReportMissingAttr(lexer, node, "alt");
    }
    if (!HasHref)
        ReportMissingAttr(lexer, node, "href");
}

void CheckTABLE(Lexer *lexer, Node *node)
{
    AttVal *attval;
    Attribute *attribute;
    Bool HasSummary = no;

    for (attval = node->attributes; attval != null; attval = attval->next)
    {
        attribute = CheckAttribute(lexer, node, attval);

        if (attribute == attr_summary)
            HasSummary = yes;
    }

    /* suppress warning for missing summary for HTML 2.0 and HTML 3.2 */
    if (!HasSummary && lexer->doctype != VERS_HTML20 && lexer->doctype != VERS_HTML32)
    {
        lexer->badAccess |= MISSING_SUMMARY;
        ReportMissingAttr(lexer, node, "summary");
    }

    /* convert <table border> to <table border="1"> */
    if (XmlOut && (attval = GetAttrByName(node, "border")))
    {
        if (attval->value == null)
            attval->value = wstrdup("1");
    }

    /* <table height="..."> is proprietary */
    if (attval = GetAttrByName(node, "height"))
    {
        ReportAttrError(lexer, node, attval, PROPRIETARY_ATTRIBUTE);
        ConstrainVersion(lexer, VERS_PROPRIETARY);
    }
}

/* add missing type attribute when appropriate */
void CheckSCRIPT(Lexer *lexer, Node *node)
{
    AttVal *lang, *type;
    char buf[16];

    CheckAttributes(lexer, node);

    lang = GetAttrByName(node, "language");
    type = GetAttrByName(node, "type");

    if (!type)
    {
        ReportMissingAttr(lexer, node, "type");

        /* check for javascript */

        if (lang)
        {
            wstrncpy(buf, lang->value, 10);
            buf[10] = '\0';

            if ( (wstrncasecmp(buf, "javascript", 10) == 0) ||
                 (wstrncasecmp(buf,    "jscript", 7) == 0) )
            {
                AddAttribute(node, "type", "text/javascript");
            }
            else if ( wstrcasecmp(buf, "vbscript") == 0 )
            {
               /* per Randy Waki 8/6/01 */
                AddAttribute(node, "type", "text/vbscript");
            }
        }
        else
            AddAttribute(node, "type", "text/javascript");
    }
}


/* add missing type attribute when appropriate */
void CheckSTYLE(Lexer *lexer, Node *node)
{
    AttVal *type = GetAttrByName(node, "type");

    CheckAttributes(lexer, node);

    if (!type)
    {
        ReportMissingAttr(lexer, node, "type");

        AddAttribute(node, "type", "text/css");
    }
}

/* add missing type attribute when appropriate */
void CheckLINK(Lexer *lexer, Node *node)
{
    AttVal *rel = GetAttrByName(node, "rel");

    CheckAttributes(lexer, node);

    if (rel && rel->value &&
          wstrcmp(rel->value, "stylesheet") == 0)
    {
        AttVal *type = GetAttrByName(node, "type");

        if (!type)
        {
            ReportMissingAttr(lexer, node, "type");

            AddAttribute(node, "type", "text/css");
        }
    }
}

/* reports missing action attribute */
void CheckFORM(Lexer *lexer, Node *node)
{
    AttVal *action = GetAttrByName(node, "action");

    CheckAttributes(lexer, node);

    if (!action)
        ReportMissingAttr(lexer, node, "action");
}

/* reports missing content attribute */
void CheckMETA(Lexer *lexer, Node *node)
{
    AttVal *content = GetAttrByName(node, "content");

    CheckAttributes(lexer, node);

    if (!content)
        ReportMissingAttr(lexer, node, "content");

    /* name or http-equiv attribute must also be set */
}


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