--- /dev/null
+<?php
+
+/**
+ * Takes tokens makes them well-formed (balance end tags, etc.)
+ *
+ * Specification of the armor attributes this strategy uses:
+ *
+ * - MakeWellFormed_TagClosedError: This armor field is used to
+ * suppress tag closed errors for certain tokens [TagClosedSuppress],
+ * in particular, if a tag was generated automatically by HTML
+ * Purifier, we may rely on our infrastructure to close it for us
+ * and shouldn't report an error to the user [TagClosedAuto].
+ */
+class HTMLPurifier_Strategy_MakeWellFormed extends HTMLPurifier_Strategy
+{
+
+ /**
+ * Array stream of tokens being processed.
+ * @type HTMLPurifier_Token[]
+ */
+ protected $tokens;
+
+ /**
+ * Current token.
+ * @type HTMLPurifier_Token
+ */
+ protected $token;
+
+ /**
+ * Zipper managing the true state.
+ * @type HTMLPurifier_Zipper
+ */
+ protected $zipper;
+
+ /**
+ * Current nesting of elements.
+ * @type array
+ */
+ protected $stack;
+
+ /**
+ * Injectors active in this stream processing.
+ * @type HTMLPurifier_Injector[]
+ */
+ protected $injectors;
+
+ /**
+ * Current instance of HTMLPurifier_Config.
+ * @type HTMLPurifier_Config
+ */
+ protected $config;
+
+ /**
+ * Current instance of HTMLPurifier_Context.
+ * @type HTMLPurifier_Context
+ */
+ protected $context;
+
+ /**
+ * @param HTMLPurifier_Token[] $tokens
+ * @param HTMLPurifier_Config $config
+ * @param HTMLPurifier_Context $context
+ * @return HTMLPurifier_Token[]
+ * @throws HTMLPurifier_Exception
+ */
+ public function execute($tokens, $config, $context)
+ {
+ $definition = $config->getHTMLDefinition();
+
+ // local variables
+ $generator = new HTMLPurifier_Generator($config, $context);
+ $escape_invalid_tags = $config->get('Core.EscapeInvalidTags');
+ // used for autoclose early abortion
+ $global_parent_allowed_elements = $definition->info_parent_def->child->getAllowedElements($config);
+ $e = $context->get('ErrorCollector', true);
+ $i = false; // injector index
+ list($zipper, $token) = HTMLPurifier_Zipper::fromArray($tokens);
+ if ($token === NULL) {
+ return array();
+ }
+ $reprocess = false; // whether or not to reprocess the same token
+ $stack = array();
+
+ // member variables
+ $this->stack =& $stack;
+ $this->tokens =& $tokens;
+ $this->token =& $token;
+ $this->zipper =& $zipper;
+ $this->config = $config;
+ $this->context = $context;
+
+ // context variables
+ $context->register('CurrentNesting', $stack);
+ $context->register('InputZipper', $zipper);
+ $context->register('CurrentToken', $token);
+
+ // -- begin INJECTOR --
+
+ $this->injectors = array();
+
+ $injectors = $config->getBatch('AutoFormat');
+ $def_injectors = $definition->info_injector;
+ $custom_injectors = $injectors['Custom'];
+ unset($injectors['Custom']); // special case
+ foreach ($injectors as $injector => $b) {
+ // XXX: Fix with a legitimate lookup table of enabled filters
+ if (strpos($injector, '.') !== false) {
+ continue;
+ }
+ $injector = "HTMLPurifier_Injector_$injector";
+ if (!$b) {
+ continue;
+ }
+ $this->injectors[] = new $injector;
+ }
+ foreach ($def_injectors as $injector) {
+ // assumed to be objects
+ $this->injectors[] = $injector;
+ }
+ foreach ($custom_injectors as $injector) {
+ if (!$injector) {
+ continue;
+ }
+ if (is_string($injector)) {
+ $injector = "HTMLPurifier_Injector_$injector";
+ $injector = new $injector;
+ }
+ $this->injectors[] = $injector;
+ }
+
+ // give the injectors references to the definition and context
+ // variables for performance reasons
+ foreach ($this->injectors as $ix => $injector) {
+ $error = $injector->prepare($config, $context);
+ if (!$error) {
+ continue;
+ }
+ array_splice($this->injectors, $ix, 1); // rm the injector
+ trigger_error("Cannot enable {$injector->name} injector because $error is not allowed", E_USER_WARNING);
+ }
+
+ // -- end INJECTOR --
+
+ // a note on reprocessing:
+ // In order to reduce code duplication, whenever some code needs
+ // to make HTML changes in order to make things "correct", the
+ // new HTML gets sent through the purifier, regardless of its
+ // status. This means that if we add a start token, because it
+ // was totally necessary, we don't have to update nesting; we just
+ // punt ($reprocess = true; continue;) and it does that for us.
+
+ // isset is in loop because $tokens size changes during loop exec
+ for (;;
+ // only increment if we don't need to reprocess
+ $reprocess ? $reprocess = false : $token = $zipper->next($token)) {
+
+ // check for a rewind
+ if (is_int($i)) {
+ // possibility: disable rewinding if the current token has a
+ // rewind set on it already. This would offer protection from
+ // infinite loop, but might hinder some advanced rewinding.
+ $rewind_offset = $this->injectors[$i]->getRewindOffset();
+ if (is_int($rewind_offset)) {
+ for ($j = 0; $j < $rewind_offset; $j++) {
+ if (empty($zipper->front)) break;
+ $token = $zipper->prev($token);
+ // indicate that other injectors should not process this token,
+ // but we need to reprocess it. See Note [Injector skips]
+ unset($token->skip[$i]);
+ $token->rewind = $i;
+ if ($token instanceof HTMLPurifier_Token_Start) {
+ array_pop($this->stack);
+ } elseif ($token instanceof HTMLPurifier_Token_End) {
+ $this->stack[] = $token->start;
+ }
+ }
+ }
+ $i = false;
+ }
+
+ // handle case of document end
+ if ($token === NULL) {
+ // kill processing if stack is empty
+ if (empty($this->stack)) {
+ break;
+ }
+
+ // peek
+ $top_nesting = array_pop($this->stack);
+ $this->stack[] = $top_nesting;
+
+ // send error [TagClosedSuppress]
+ if ($e && !isset($top_nesting->armor['MakeWellFormed_TagClosedError'])) {
+ $e->send(E_NOTICE, 'Strategy_MakeWellFormed: Tag closed by document end', $top_nesting);
+ }
+
+ // append, don't splice, since this is the end
+ $token = new HTMLPurifier_Token_End($top_nesting->name);
+
+ // punt!
+ $reprocess = true;
+ continue;
+ }
+
+ //echo '<br>'; printZipper($zipper, $token);//printTokens($this->stack);
+ //flush();
+
+ // quick-check: if it's not a tag, no need to process
+ if (empty($token->is_tag)) {
+ if ($token instanceof HTMLPurifier_Token_Text) {
+ foreach ($this->injectors as $i => $injector) {
+ if (isset($token->skip[$i])) {
+ // See Note [Injector skips]
+ continue;
+ }
+ if ($token->rewind !== null && $token->rewind !== $i) {
+ continue;
+ }
+ // XXX fuckup
+ $r = $token;
+ $injector->handleText($r);
+ $token = $this->processToken($r, $i);
+ $reprocess = true;
+ break;
+ }
+ }
+ // another possibility is a comment
+ continue;
+ }
+
+ if (isset($definition->info[$token->name])) {
+ $type = $definition->info[$token->name]->child->type;
+ } else {
+ $type = false; // Type is unknown, treat accordingly
+ }
+
+ // quick tag checks: anything that's *not* an end tag
+ $ok = false;
+ if ($type === 'empty' && $token instanceof HTMLPurifier_Token_Start) {
+ // claims to be a start tag but is empty
+ $token = new HTMLPurifier_Token_Empty(
+ $token->name,
+ $token->attr,
+ $token->line,
+ $token->col,
+ $token->armor
+ );
+ $ok = true;
+ } elseif ($type && $type !== 'empty' && $token instanceof HTMLPurifier_Token_Empty) {
+ // claims to be empty but really is a start tag
+ // NB: this assignment is required
+ $old_token = $token;
+ $token = new HTMLPurifier_Token_End($token->name);
+ $token = $this->insertBefore(
+ new HTMLPurifier_Token_Start($old_token->name, $old_token->attr, $old_token->line, $old_token->col, $old_token->armor)
+ );
+ // punt (since we had to modify the input stream in a non-trivial way)
+ $reprocess = true;
+ continue;
+ } elseif ($token instanceof HTMLPurifier_Token_Empty) {
+ // real empty token
+ $ok = true;
+ } elseif ($token instanceof HTMLPurifier_Token_Start) {
+ // start tag
+
+ // ...unless they also have to close their parent
+ if (!empty($this->stack)) {
+
+ // Performance note: you might think that it's rather
+ // inefficient, recalculating the autoclose information
+ // for every tag that a token closes (since when we
+ // do an autoclose, we push a new token into the
+ // stream and then /process/ that, before
+ // re-processing this token.) But this is
+ // necessary, because an injector can make an
+ // arbitrary transformations to the autoclosing
+ // tokens we introduce, so things may have changed
+ // in the meantime. Also, doing the inefficient thing is
+ // "easy" to reason about (for certain perverse definitions
+ // of "easy")
+
+ $parent = array_pop($this->stack);
+ $this->stack[] = $parent;
+
+ $parent_def = null;
+ $parent_elements = null;
+ $autoclose = false;
+ if (isset($definition->info[$parent->name])) {
+ $parent_def = $definition->info[$parent->name];
+ $parent_elements = $parent_def->child->getAllowedElements($config);
+ $autoclose = !isset($parent_elements[$token->name]);
+ }
+
+ if ($autoclose && $definition->info[$token->name]->wrap) {
+ // Check if an element can be wrapped by another
+ // element to make it valid in a context (for
+ // example, <ul><ul> needs a <li> in between)
+ $wrapname = $definition->info[$token->name]->wrap;
+ $wrapdef = $definition->info[$wrapname];
+ $elements = $wrapdef->child->getAllowedElements($config);
+ if (isset($elements[$token->name]) && isset($parent_elements[$wrapname])) {
+ $newtoken = new HTMLPurifier_Token_Start($wrapname);
+ $token = $this->insertBefore($newtoken);
+ $reprocess = true;
+ continue;
+ }
+ }
+
+ $carryover = false;
+ if ($autoclose && $parent_def->formatting) {
+ $carryover = true;
+ }
+
+ if ($autoclose) {
+ // check if this autoclose is doomed to fail
+ // (this rechecks $parent, which his harmless)
+ $autoclose_ok = isset($global_parent_allowed_elements[$token->name]);
+ if (!$autoclose_ok) {
+ foreach ($this->stack as $ancestor) {
+ $elements = $definition->info[$ancestor->name]->child->getAllowedElements($config);
+ if (isset($elements[$token->name])) {
+ $autoclose_ok = true;
+ break;
+ }
+ if ($definition->info[$token->name]->wrap) {
+ $wrapname = $definition->info[$token->name]->wrap;
+ $wrapdef = $definition->info[$wrapname];
+ $wrap_elements = $wrapdef->child->getAllowedElements($config);
+ if (isset($wrap_elements[$token->name]) && isset($elements[$wrapname])) {
+ $autoclose_ok = true;
+ break;
+ }
+ }
+ }
+ }
+ if ($autoclose_ok) {
+ // errors need to be updated
+ $new_token = new HTMLPurifier_Token_End($parent->name);
+ $new_token->start = $parent;
+ // [TagClosedSuppress]
+ if ($e && !isset($parent->armor['MakeWellFormed_TagClosedError'])) {
+ if (!$carryover) {
+ $e->send(E_NOTICE, 'Strategy_MakeWellFormed: Tag auto closed', $parent);
+ } else {
+ $e->send(E_NOTICE, 'Strategy_MakeWellFormed: Tag carryover', $parent);
+ }
+ }
+ if ($carryover) {
+ $element = clone $parent;
+ // [TagClosedAuto]
+ $element->armor['MakeWellFormed_TagClosedError'] = true;
+ $element->carryover = true;
+ $token = $this->processToken(array($new_token, $token, $element));
+ } else {
+ $token = $this->insertBefore($new_token);
+ }
+ } else {
+ $token = $this->remove();
+ }
+ $reprocess = true;
+ continue;
+ }
+
+ }
+ $ok = true;
+ }
+
+ if ($ok) {
+ foreach ($this->injectors as $i => $injector) {
+ if (isset($token->skip[$i])) {
+ // See Note [Injector skips]
+ continue;
+ }
+ if ($token->rewind !== null && $token->rewind !== $i) {
+ continue;
+ }
+ $r = $token;
+ $injector->handleElement($r);
+ $token = $this->processToken($r, $i);
+ $reprocess = true;
+ break;
+ }
+ if (!$reprocess) {
+ // ah, nothing interesting happened; do normal processing
+ if ($token instanceof HTMLPurifier_Token_Start) {
+ $this->stack[] = $token;
+ } elseif ($token instanceof HTMLPurifier_Token_End) {
+ throw new HTMLPurifier_Exception(
+ 'Improper handling of end tag in start code; possible error in MakeWellFormed'
+ );
+ }
+ }
+ continue;
+ }
+
+ // sanity check: we should be dealing with a closing tag
+ if (!$token instanceof HTMLPurifier_Token_End) {
+ throw new HTMLPurifier_Exception('Unaccounted for tag token in input stream, bug in HTML Purifier');
+ }
+
+ // make sure that we have something open
+ if (empty($this->stack)) {
+ if ($escape_invalid_tags) {
+ if ($e) {
+ $e->send(E_WARNING, 'Strategy_MakeWellFormed: Unnecessary end tag to text');
+ }
+ $token = new HTMLPurifier_Token_Text($generator->generateFromToken($token));
+ } else {
+ if ($e) {
+ $e->send(E_WARNING, 'Strategy_MakeWellFormed: Unnecessary end tag removed');
+ }
+ $token = $this->remove();
+ }
+ $reprocess = true;
+ continue;
+ }
+
+ // first, check for the simplest case: everything closes neatly.
+ // Eventually, everything passes through here; if there are problems
+ // we modify the input stream accordingly and then punt, so that
+ // the tokens get processed again.
+ $current_parent = array_pop($this->stack);
+ if ($current_parent->name == $token->name) {
+ $token->start = $current_parent;
+ foreach ($this->injectors as $i => $injector) {
+ if (isset($token->skip[$i])) {
+ // See Note [Injector skips]
+ continue;
+ }
+ if ($token->rewind !== null && $token->rewind !== $i) {
+ continue;
+ }
+ $r = $token;
+ $injector->handleEnd($r);
+ $token = $this->processToken($r, $i);
+ $this->stack[] = $current_parent;
+ $reprocess = true;
+ break;
+ }
+ continue;
+ }
+
+ // okay, so we're trying to close the wrong tag
+
+ // undo the pop previous pop
+ $this->stack[] = $current_parent;
+
+ // scroll back the entire nest, trying to find our tag.
+ // (feature could be to specify how far you'd like to go)
+ $size = count($this->stack);
+ // -2 because -1 is the last element, but we already checked that
+ $skipped_tags = false;
+ for ($j = $size - 2; $j >= 0; $j--) {
+ if ($this->stack[$j]->name == $token->name) {
+ $skipped_tags = array_slice($this->stack, $j);
+ break;
+ }
+ }
+
+ // we didn't find the tag, so remove
+ if ($skipped_tags === false) {
+ if ($escape_invalid_tags) {
+ if ($e) {
+ $e->send(E_WARNING, 'Strategy_MakeWellFormed: Stray end tag to text');
+ }
+ $token = new HTMLPurifier_Token_Text($generator->generateFromToken($token));
+ } else {
+ if ($e) {
+ $e->send(E_WARNING, 'Strategy_MakeWellFormed: Stray end tag removed');
+ }
+ $token = $this->remove();
+ }
+ $reprocess = true;
+ continue;
+ }
+
+ // do errors, in REVERSE $j order: a,b,c with </a></b></c>
+ $c = count($skipped_tags);
+ if ($e) {
+ for ($j = $c - 1; $j > 0; $j--) {
+ // notice we exclude $j == 0, i.e. the current ending tag, from
+ // the errors... [TagClosedSuppress]
+ if (!isset($skipped_tags[$j]->armor['MakeWellFormed_TagClosedError'])) {
+ $e->send(E_NOTICE, 'Strategy_MakeWellFormed: Tag closed by element end', $skipped_tags[$j]);
+ }
+ }
+ }
+
+ // insert tags, in FORWARD $j order: c,b,a with </a></b></c>
+ $replace = array($token);
+ for ($j = 1; $j < $c; $j++) {
+ // ...as well as from the insertions
+ $new_token = new HTMLPurifier_Token_End($skipped_tags[$j]->name);
+ $new_token->start = $skipped_tags[$j];
+ array_unshift($replace, $new_token);
+ if (isset($definition->info[$new_token->name]) && $definition->info[$new_token->name]->formatting) {
+ // [TagClosedAuto]
+ $element = clone $skipped_tags[$j];
+ $element->carryover = true;
+ $element->armor['MakeWellFormed_TagClosedError'] = true;
+ $replace[] = $element;
+ }
+ }
+ $token = $this->processToken($replace);
+ $reprocess = true;
+ continue;
+ }
+
+ $context->destroy('CurrentToken');
+ $context->destroy('CurrentNesting');
+ $context->destroy('InputZipper');
+
+ unset($this->injectors, $this->stack, $this->tokens);
+ return $zipper->toArray($token);
+ }
+
+ /**
+ * Processes arbitrary token values for complicated substitution patterns.
+ * In general:
+ *
+ * If $token is an array, it is a list of tokens to substitute for the
+ * current token. These tokens then get individually processed. If there
+ * is a leading integer in the list, that integer determines how many
+ * tokens from the stream should be removed.
+ *
+ * If $token is a regular token, it is swapped with the current token.
+ *
+ * If $token is false, the current token is deleted.
+ *
+ * If $token is an integer, that number of tokens (with the first token
+ * being the current one) will be deleted.
+ *
+ * @param HTMLPurifier_Token|array|int|bool $token Token substitution value
+ * @param HTMLPurifier_Injector|int $injector Injector that performed the substitution; default is if
+ * this is not an injector related operation.
+ * @throws HTMLPurifier_Exception
+ */
+ protected function processToken($token, $injector = -1)
+ {
+ // Zend OpCache miscompiles $token = array($token), so
+ // avoid this pattern. See: https://github.com/ezyang/htmlpurifier/issues/108
+
+ // normalize forms of token
+ if (is_object($token)) {
+ $tmp = $token;
+ $token = array(1, $tmp);
+ }
+ if (is_int($token)) {
+ $tmp = $token;
+ $token = array($tmp);
+ }
+ if ($token === false) {
+ $token = array(1);
+ }
+ if (!is_array($token)) {
+ throw new HTMLPurifier_Exception('Invalid token type from injector');
+ }
+ if (!is_int($token[0])) {
+ array_unshift($token, 1);
+ }
+ if ($token[0] === 0) {
+ throw new HTMLPurifier_Exception('Deleting zero tokens is not valid');
+ }
+
+ // $token is now an array with the following form:
+ // array(number nodes to delete, new node 1, new node 2, ...)
+
+ $delete = array_shift($token);
+ list($old, $r) = $this->zipper->splice($this->token, $delete, $token);
+
+ if ($injector > -1) {
+ // See Note [Injector skips]
+ // Determine appropriate skips. Here's what the code does:
+ // *If* we deleted one or more tokens, copy the skips
+ // of those tokens into the skips of the new tokens (in $token).
+ // Also, mark the newly inserted tokens as having come from
+ // $injector.
+ $oldskip = isset($old[0]) ? $old[0]->skip : array();
+ foreach ($token as $object) {
+ $object->skip = $oldskip;
+ $object->skip[$injector] = true;
+ }
+ }
+
+ return $r;
+
+ }
+
+ /**
+ * Inserts a token before the current token. Cursor now points to
+ * this token. You must reprocess after this.
+ * @param HTMLPurifier_Token $token
+ */
+ private function insertBefore($token)
+ {
+ // NB not $this->zipper->insertBefore(), due to positioning
+ // differences
+ $splice = $this->zipper->splice($this->token, 0, array($token));
+
+ return $splice[1];
+ }
+
+ /**
+ * Removes current token. Cursor now points to new token occupying previously
+ * occupied space. You must reprocess after this.
+ */
+ private function remove()
+ {
+ return $this->zipper->delete();
+ }
+}
+
+// Note [Injector skips]
+// ~~~~~~~~~~~~~~~~~~~~~
+// When I originally designed this class, the idea behind the 'skip'
+// property of HTMLPurifier_Token was to help avoid infinite loops
+// in injector processing. For example, suppose you wrote an injector
+// that bolded swear words. Naively, you might write it so that
+// whenever you saw ****, you replaced it with <strong>****</strong>.
+//
+// When this happens, we will reprocess all of the tokens with the
+// other injectors. Now there is an opportunity for infinite loop:
+// if we rerun the swear-word injector on these tokens, we might
+// see **** and then reprocess again to get
+// <strong><strong>****</strong></strong> ad infinitum.
+//
+// Thus, the idea of a skip is that once we process a token with
+// an injector, we mark all of those tokens as having "come from"
+// the injector, and we never run the injector again on these
+// tokens.
+//
+// There were two more complications, however:
+//
+// - With HTMLPurifier_Injector_RemoveEmpty, we noticed that if
+// you had <b><i></i></b>, after you removed the <i></i>, you
+// really would like this injector to go back and reprocess
+// the <b> tag, discovering that it is now empty and can be
+// removed. So we reintroduced the possibility of infinite looping
+// by adding a "rewind" function, which let you go back to an
+// earlier point in the token stream and reprocess it with injectors.
+// Needless to say, we need to UN-skip the token so it gets
+// reprocessed.
+//
+// - Suppose that you successfuly process a token, replace it with
+// one with your skip mark, but now another injector wants to
+// process the skipped token with another token. Should you continue
+// to skip that new token, or reprocess it? If you reprocess,
+// you can end up with an infinite loop where one injector converts
+// <a> to <b>, and then another injector converts it back. So
+// we inherit the skips, but for some reason, I thought that we
+// should inherit the skip from the first token of the token
+// that we deleted. Why? Well, it seems to work OK.
+//
+// If I were to redesign this functionality, I would absolutely not
+// go about doing it this way: the semantics are just not very well
+// defined, and in any case you probably wanted to operate on trees,
+// not token streams.
+
+// vim: et sw=4 sts=4
projects / yaffs-website / blobdiff