:arrow_up: Update HTML Purifier library.

Updated HTML Purifier from 4.6.0 to 4.9.2 with better PHP7 compatibility.
Used composer to manage this library.

6 files changed, 1139 insertions, 0 deletions

diff --git a/vendor/ezyang/htmlpurifier/library/HTMLPurifier/Strategy/Composite.php b/vendor/ezyang/htmlpurifier/library/HTMLPurifier/Strategy/Composite.php
new file mode 100644
index 000000000..d7d35ce7d
--- /dev/null
+++ b/vendor/ezyang/htmlpurifier/library/HTMLPurifier/Strategy/Composite.php
@@ -0,0 +1,30 @@
+<?php
+
+/**
+ * Composite strategy that runs multiple strategies on tokens.
+ */
+abstract class HTMLPurifier_Strategy_Composite extends HTMLPurifier_Strategy
+{
+
+    /**
+     * List of strategies to run tokens through.
+     * @type HTMLPurifier_Strategy[]
+     */
+    protected $strategies = array();
+
+    /**
+     * @param HTMLPurifier_Token[] $tokens
+     * @param HTMLPurifier_Config $config
+     * @param HTMLPurifier_Context $context
+     * @return HTMLPurifier_Token[]
+     */
+    public function execute($tokens, $config, $context)
+    {
+        foreach ($this->strategies as $strategy) {
+            $tokens = $strategy->execute($tokens, $config, $context);
+        }
+        return $tokens;
+    }
+}
+
+// vim: et sw=4 sts=4
diff --git a/vendor/ezyang/htmlpurifier/library/HTMLPurifier/Strategy/Core.php b/vendor/ezyang/htmlpurifier/library/HTMLPurifier/Strategy/Core.php
new file mode 100644
index 000000000..4414c17d6
--- /dev/null
+++ b/vendor/ezyang/htmlpurifier/library/HTMLPurifier/Strategy/Core.php
@@ -0,0 +1,17 @@
+<?php
+
+/**
+ * Core strategy composed of the big four strategies.
+ */
+class HTMLPurifier_Strategy_Core extends HTMLPurifier_Strategy_Composite
+{
+    public function __construct()
+    {
+        $this->strategies[] = new HTMLPurifier_Strategy_RemoveForeignElements();
+        $this->strategies[] = new HTMLPurifier_Strategy_MakeWellFormed();
+        $this->strategies[] = new HTMLPurifier_Strategy_FixNesting();
+        $this->strategies[] = new HTMLPurifier_Strategy_ValidateAttributes();
+    }
+}
+
+// vim: et sw=4 sts=4
diff --git a/vendor/ezyang/htmlpurifier/library/HTMLPurifier/Strategy/FixNesting.php b/vendor/ezyang/htmlpurifier/library/HTMLPurifier/Strategy/FixNesting.php
new file mode 100644
index 000000000..6fa673db9
--- /dev/null
+++ b/vendor/ezyang/htmlpurifier/library/HTMLPurifier/Strategy/FixNesting.php
@@ -0,0 +1,181 @@
+<?php
+
+/**
+ * Takes a well formed list of tokens and fixes their nesting.
+ *
+ * HTML elements dictate which elements are allowed to be their children,
+ * for example, you can't have a p tag in a span tag.  Other elements have
+ * much more rigorous definitions: tables, for instance, require a specific
+ * order for their elements.  There are also constraints not expressible by
+ * document type definitions, such as the chameleon nature of ins/del
+ * tags and global child exclusions.
+ *
+ * The first major objective of this strategy is to iterate through all
+ * the nodes and determine whether or not their children conform to the
+ * element's definition.  If they do not, the child definition may
+ * optionally supply an amended list of elements that is valid or
+ * require that the entire node be deleted (and the previous node
+ * rescanned).
+ *
+ * The second objective is to ensure that explicitly excluded elements of
+ * an element do not appear in its children.  Code that accomplishes this
+ * task is pervasive through the strategy, though the two are distinct tasks
+ * and could, theoretically, be seperated (although it's not recommended).
+ *
+ * @note Whether or not unrecognized children are silently dropped or
+ *       translated into text depends on the child definitions.
+ *
+ * @todo Enable nodes to be bubbled out of the structure.  This is
+ *       easier with our new algorithm.
+ */
+
+class HTMLPurifier_Strategy_FixNesting extends HTMLPurifier_Strategy
+{
+
+    /**
+     * @param HTMLPurifier_Token[] $tokens
+     * @param HTMLPurifier_Config $config
+     * @param HTMLPurifier_Context $context
+     * @return array|HTMLPurifier_Token[]
+     */
+    public function execute($tokens, $config, $context)
+    {
+
+        //####################################################################//
+        // Pre-processing
+
+        // O(n) pass to convert to a tree, so that we can efficiently
+        // refer to substrings
+        $top_node = HTMLPurifier_Arborize::arborize($tokens, $config, $context);
+
+        // get a copy of the HTML definition
+        $definition = $config->getHTMLDefinition();
+
+        $excludes_enabled = !$config->get('Core.DisableExcludes');
+
+        // setup the context variable 'IsInline', for chameleon processing
+        // is 'false' when we are not inline, 'true' when it must always
+        // be inline, and an integer when it is inline for a certain
+        // branch of the document tree
+        $is_inline = $definition->info_parent_def->descendants_are_inline;
+        $context->register('IsInline', $is_inline);
+
+        // setup error collector
+        $e =& $context->get('ErrorCollector', true);
+
+        //####################################################################//
+        // Loop initialization
+
+        // stack that contains all elements that are excluded
+        // it is organized by parent elements, similar to $stack,
+        // but it is only populated when an element with exclusions is
+        // processed, i.e. there won't be empty exclusions.
+        $exclude_stack = array($definition->info_parent_def->excludes);
+
+        // variable that contains the start token while we are processing
+        // nodes. This enables error reporting to do its job
+        $node = $top_node;
+        // dummy token
+        list($token, $d) = $node->toTokenPair();
+        $context->register('CurrentNode', $node);
+        $context->register('CurrentToken', $token);
+
+        //####################################################################//
+        // Loop
+
+        // We need to implement a post-order traversal iteratively, to
+        // avoid running into stack space limits.  This is pretty tricky
+        // to reason about, so we just manually stack-ify the recursive
+        // variant:
+        //
+        //  function f($node) {
+        //      foreach ($node->children as $child) {
+        //          f($child);
+        //      }
+        //      validate($node);
+        //  }
+        //
+        // Thus, we will represent a stack frame as array($node,
+        // $is_inline, stack of children)
+        // e.g. array_reverse($node->children) - already processed
+        // children.
+
+        $parent_def = $definition->info_parent_def;
+        $stack = array(
+            array($top_node,
+                  $parent_def->descendants_are_inline,
+                  $parent_def->excludes, // exclusions
+                  0)
+            );
+
+        while (!empty($stack)) {
+            list($node, $is_inline, $excludes, $ix) = array_pop($stack);
+            // recursive call
+            $go = false;
+            $def = empty($stack) ? $definition->info_parent_def : $definition->info[$node->name];
+            while (isset($node->children[$ix])) {
+                $child = $node->children[$ix++];
+                if ($child instanceof HTMLPurifier_Node_Element) {
+                    $go = true;
+                    $stack[] = array($node, $is_inline, $excludes, $ix);
+                    $stack[] = array($child,
+                        // ToDo: I don't think it matters if it's def or
+                        // child_def, but double check this...
+                        $is_inline || $def->descendants_are_inline,
+                        empty($def->excludes) ? $excludes
+                                              : array_merge($excludes, $def->excludes),
+                        0);
+                    break;
+                }
+            };
+            if ($go) continue;
+            list($token, $d) = $node->toTokenPair();
+            // base case
+            if ($excludes_enabled && isset($excludes[$node->name])) {
+                $node->dead = true;
+                if ($e) $e->send(E_ERROR, 'Strategy_FixNesting: Node excluded');
+            } else {
+                // XXX I suppose it would be slightly more efficient to
+                // avoid the allocation here and have children
+                // strategies handle it
+                $children = array();
+                foreach ($node->children as $child) {
+                    if (!$child->dead) $children[] = $child;
+                }
+                $result = $def->child->validateChildren($children, $config, $context);
+                if ($result === true) {
+                    // nop
+                    $node->children = $children;
+                } elseif ($result === false) {
+                    $node->dead = true;
+                    if ($e) $e->send(E_ERROR, 'Strategy_FixNesting: Node removed');
+                } else {
+                    $node->children = $result;
+                    if ($e) {
+                        // XXX This will miss mutations of internal nodes. Perhaps defer to the child validators
+                        if (empty($result) && !empty($children)) {
+                            $e->send(E_ERROR, 'Strategy_FixNesting: Node contents removed');
+                        } else if ($result != $children) {
+                            $e->send(E_WARNING, 'Strategy_FixNesting: Node reorganized');
+                        }
+                    }
+                }
+            }
+        }
+
+        //####################################################################//
+        // Post-processing
+
+        // remove context variables
+        $context->destroy('IsInline');
+        $context->destroy('CurrentNode');
+        $context->destroy('CurrentToken');
+
+        //####################################################################//
+        // Return
+
+        return HTMLPurifier_Arborize::flatten($node, $config, $context);
+    }
+}
+
+// vim: et sw=4 sts=4
diff --git a/vendor/ezyang/htmlpurifier/library/HTMLPurifier/Strategy/MakeWellFormed.php b/vendor/ezyang/htmlpurifier/library/HTMLPurifier/Strategy/MakeWellFormed.php
new file mode 100644
index 000000000..a6eb09e45
--- /dev/null
+++ b/vendor/ezyang/htmlpurifier/library/HTMLPurifier/Strategy/MakeWellFormed.php
@@ -0,0 +1,659 @@
+<?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
diff --git a/vendor/ezyang/htmlpurifier/library/HTMLPurifier/Strategy/RemoveForeignElements.php b/vendor/ezyang/htmlpurifier/library/HTMLPurifier/Strategy/RemoveForeignElements.php
new file mode 100644
index 000000000..1a8149ecc
--- /dev/null
+++ b/vendor/ezyang/htmlpurifier/library/HTMLPurifier/Strategy/RemoveForeignElements.php
@@ -0,0 +1,207 @@
+<?php
+
+/**
+ * Removes all unrecognized tags from the list of tokens.
+ *
+ * This strategy iterates through all the tokens and removes unrecognized
+ * tokens. If a token is not recognized but a TagTransform is defined for
+ * that element, the element will be transformed accordingly.
+ */
+
+class HTMLPurifier_Strategy_RemoveForeignElements extends HTMLPurifier_Strategy
+{
+
+    /**
+     * @param HTMLPurifier_Token[] $tokens
+     * @param HTMLPurifier_Config $config
+     * @param HTMLPurifier_Context $context
+     * @return array|HTMLPurifier_Token[]
+     */
+    public function execute($tokens, $config, $context)
+    {
+        $definition = $config->getHTMLDefinition();
+        $generator = new HTMLPurifier_Generator($config, $context);
+        $result = array();
+
+        $escape_invalid_tags = $config->get('Core.EscapeInvalidTags');
+        $remove_invalid_img = $config->get('Core.RemoveInvalidImg');
+
+        // currently only used to determine if comments should be kept
+        $trusted = $config->get('HTML.Trusted');
+        $comment_lookup = $config->get('HTML.AllowedComments');
+        $comment_regexp = $config->get('HTML.AllowedCommentsRegexp');
+        $check_comments = $comment_lookup !== array() || $comment_regexp !== null;
+
+        $remove_script_contents = $config->get('Core.RemoveScriptContents');
+        $hidden_elements = $config->get('Core.HiddenElements');
+
+        // remove script contents compatibility
+        if ($remove_script_contents === true) {
+            $hidden_elements['script'] = true;
+        } elseif ($remove_script_contents === false && isset($hidden_elements['script'])) {
+            unset($hidden_elements['script']);
+        }
+
+        $attr_validator = new HTMLPurifier_AttrValidator();
+
+        // removes tokens until it reaches a closing tag with its value
+        $remove_until = false;
+
+        // converts comments into text tokens when this is equal to a tag name
+        $textify_comments = false;
+
+        $token = false;
+        $context->register('CurrentToken', $token);
+
+        $e = false;
+        if ($config->get('Core.CollectErrors')) {
+            $e =& $context->get('ErrorCollector');
+        }
+
+        foreach ($tokens as $token) {
+            if ($remove_until) {
+                if (empty($token->is_tag) || $token->name !== $remove_until) {
+                    continue;
+                }
+            }
+            if (!empty($token->is_tag)) {
+                // DEFINITION CALL
+
+                // before any processing, try to transform the element
+                if (isset($definition->info_tag_transform[$token->name])) {
+                    $original_name = $token->name;
+                    // there is a transformation for this tag
+                    // DEFINITION CALL
+                    $token = $definition->
+                        info_tag_transform[$token->name]->transform($token, $config, $context);
+                    if ($e) {
+                        $e->send(E_NOTICE, 'Strategy_RemoveForeignElements: Tag transform', $original_name);
+                    }
+                }
+
+                if (isset($definition->info[$token->name])) {
+                    // mostly everything's good, but
+                    // we need to make sure required attributes are in order
+                    if (($token instanceof HTMLPurifier_Token_Start || $token instanceof HTMLPurifier_Token_Empty) &&
+                        $definition->info[$token->name]->required_attr &&
+                        ($token->name != 'img' || $remove_invalid_img) // ensure config option still works
+                    ) {
+                        $attr_validator->validateToken($token, $config, $context);
+                        $ok = true;
+                        foreach ($definition->info[$token->name]->required_attr as $name) {
+                            if (!isset($token->attr[$name])) {
+                                $ok = false;
+                                break;
+                            }
+                        }
+                        if (!$ok) {
+                            if ($e) {
+                                $e->send(
+                                    E_ERROR,
+                                    'Strategy_RemoveForeignElements: Missing required attribute',
+                                    $name
+                                );
+                            }
+                            continue;
+                        }
+                        $token->armor['ValidateAttributes'] = true;
+                    }
+
+                    if (isset($hidden_elements[$token->name]) && $token instanceof HTMLPurifier_Token_Start) {
+                        $textify_comments = $token->name;
+                    } elseif ($token->name === $textify_comments && $token instanceof HTMLPurifier_Token_End) {
+                        $textify_comments = false;
+                    }
+
+                } elseif ($escape_invalid_tags) {
+                    // invalid tag, generate HTML representation and insert in
+                    if ($e) {
+                        $e->send(E_WARNING, 'Strategy_RemoveForeignElements: Foreign element to text');
+                    }
+                    $token = new HTMLPurifier_Token_Text(
+                        $generator->generateFromToken($token)
+                    );
+                } else {
+                    // check if we need to destroy all of the tag's children
+                    // CAN BE GENERICIZED
+                    if (isset($hidden_elements[$token->name])) {
+                        if ($token instanceof HTMLPurifier_Token_Start) {
+                            $remove_until = $token->name;
+                        } elseif ($token instanceof HTMLPurifier_Token_Empty) {
+                            // do nothing: we're still looking
+                        } else {
+                            $remove_until = false;
+                        }
+                        if ($e) {
+                            $e->send(E_ERROR, 'Strategy_RemoveForeignElements: Foreign meta element removed');
+                        }
+                    } else {
+                        if ($e) {
+                            $e->send(E_ERROR, 'Strategy_RemoveForeignElements: Foreign element removed');
+                        }
+                    }
+                    continue;
+                }
+            } elseif ($token instanceof HTMLPurifier_Token_Comment) {
+                // textify comments in script tags when they are allowed
+                if ($textify_comments !== false) {
+                    $data = $token->data;
+                    $token = new HTMLPurifier_Token_Text($data);
+                } elseif ($trusted || $check_comments) {
+                    // always cleanup comments
+                    $trailing_hyphen = false;
+                    if ($e) {
+                        // perform check whether or not there's a trailing hyphen
+                        if (substr($token->data, -1) == '-') {
+                            $trailing_hyphen = true;
+                        }
+                    }
+                    $token->data = rtrim($token->data, '-');
+                    $found_double_hyphen = false;
+                    while (strpos($token->data, '--') !== false) {
+                        $found_double_hyphen = true;
+                        $token->data = str_replace('--', '-', $token->data);
+                    }
+                    if ($trusted || !empty($comment_lookup[trim($token->data)]) ||
+                        ($comment_regexp !== null && preg_match($comment_regexp, trim($token->data)))) {
+                        // OK good
+                        if ($e) {
+                            if ($trailing_hyphen) {
+                                $e->send(
+                                    E_NOTICE,
+                                    'Strategy_RemoveForeignElements: Trailing hyphen in comment removed'
+                                );
+                            }
+                            if ($found_double_hyphen) {
+                                $e->send(E_NOTICE, 'Strategy_RemoveForeignElements: Hyphens in comment collapsed');
+                            }
+                        }
+                    } else {
+                        if ($e) {
+                            $e->send(E_NOTICE, 'Strategy_RemoveForeignElements: Comment removed');
+                        }
+                        continue;
+                    }
+                } else {
+                    // strip comments
+                    if ($e) {
+                        $e->send(E_NOTICE, 'Strategy_RemoveForeignElements: Comment removed');
+                    }
+                    continue;
+                }
+            } elseif ($token instanceof HTMLPurifier_Token_Text) {
+            } else {
+                continue;
+            }
+            $result[] = $token;
+        }
+        if ($remove_until && $e) {
+            // we removed tokens until the end, throw error
+            $e->send(E_ERROR, 'Strategy_RemoveForeignElements: Token removed to end', $remove_until);
+        }
+        $context->destroy('CurrentToken');
+        return $result;
+    }
+}
+
+// vim: et sw=4 sts=4
diff --git a/vendor/ezyang/htmlpurifier/library/HTMLPurifier/Strategy/ValidateAttributes.php b/vendor/ezyang/htmlpurifier/library/HTMLPurifier/Strategy/ValidateAttributes.php
new file mode 100644
index 000000000..fbb3d27c8
--- /dev/null
+++ b/vendor/ezyang/htmlpurifier/library/HTMLPurifier/Strategy/ValidateAttributes.php
@@ -0,0 +1,45 @@
+<?php
+
+/**
+ * Validate all attributes in the tokens.
+ */
+
+class HTMLPurifier_Strategy_ValidateAttributes extends HTMLPurifier_Strategy
+{
+
+    /**
+     * @param HTMLPurifier_Token[] $tokens
+     * @param HTMLPurifier_Config $config
+     * @param HTMLPurifier_Context $context
+     * @return HTMLPurifier_Token[]
+     */
+    public function execute($tokens, $config, $context)
+    {
+        // setup validator
+        $validator = new HTMLPurifier_AttrValidator();
+
+        $token = false;
+        $context->register('CurrentToken', $token);
+
+        foreach ($tokens as $key => $token) {
+
+            // only process tokens that have attributes,
+            //   namely start and empty tags
+            if (!$token instanceof HTMLPurifier_Token_Start && !$token instanceof HTMLPurifier_Token_Empty) {
+                continue;
+            }
+
+            // skip tokens that are armored
+            if (!empty($token->armor['ValidateAttributes'])) {
+                continue;
+            }
+
+            // note that we have no facilities here for removing tokens
+            $validator->validateToken($token, $config, $context);
+        }
+        $context->destroy('CurrentToken');
+        return $tokens;
+    }
+}
+
+// vim: et sw=4 sts=4