mistpark 2.0 infrasturcture lands

1 files changed, 475 insertions, 0 deletions

diff --git a/library/HTMLPurifier/Strategy/MakeWellFormed.php b/library/HTMLPurifier/Strategy/MakeWellFormed.php
new file mode 100644
index 000000000..c73658400
--- /dev/null
+++ b/library/HTMLPurifier/Strategy/MakeWellFormed.php
@@ -0,0 +1,475 @@
+<?php
+
+/**
+ * Takes tokens makes them well-formed (balance end tags, etc.)
+ */
+class HTMLPurifier_Strategy_MakeWellFormed extends HTMLPurifier_Strategy
+{
+
+    /**
+     * Array stream of tokens being processed.
+     */
+    protected $tokens;
+
+    /**
+     * Current index in $tokens.
+     */
+    protected $t;
+
+    /**
+     * Current nesting of elements.
+     */
+    protected $stack;
+
+    /**
+     * Injectors active in this stream processing.
+     */
+    protected $injectors;
+
+    /**
+     * Current instance of HTMLPurifier_Config.
+     */
+    protected $config;
+
+    /**
+     * Current instance of HTMLPurifier_Context.
+     */
+    protected $context;
+
+    public function execute($tokens, $config, $context) {
+
+        $definition = $config->getHTMLDefinition();
+
+        // local variables
+        $generator = new HTMLPurifier_Generator($config, $context);
+        $escape_invalid_tags = $config->get('Core.EscapeInvalidTags');
+        $e = $context->get('ErrorCollector', true);
+        $t = false; // token index
+        $i = false; // injector index
+        $token      = false; // the current token
+        $reprocess  = false; // whether or not to reprocess the same token
+        $stack = array();
+
+        // member variables
+        $this->stack   =& $stack;
+        $this->t       =& $t;
+        $this->tokens  =& $tokens;
+        $this->config  = $config;
+        $this->context = $context;
+
+        // context variables
+        $context->register('CurrentNesting', $stack);
+        $context->register('InputIndex',     $t);
+        $context->register('InputTokens',    $tokens);
+        $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 $error is not allowed", E_USER_WARNING);
+        }
+
+        // -- end INJECTOR --
+
+        // a note on punting:
+        //      In order to reduce code duplication, whenever some code needs
+        //      to make HTML changes in order to make things "correct", the
+        //      new HTML gets sent through the purifier, regardless of its
+        //      status. This means that if we add a start token, because it
+        //      was totally necessary, we don't have to update nesting; we just
+        //      punt ($reprocess = true; continue;) and it does that for us.
+
+        // isset is in loop because $tokens size changes during loop exec
+        for (
+            $t = 0;
+            $t == 0 || isset($tokens[$t - 1]);
+            // only increment if we don't need to reprocess
+            $reprocess ? $reprocess = false : $t++
+        ) {
+
+            // check for a rewind
+            if (is_int($i) && $i >= 0) {
+                // 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_to = $this->injectors[$i]->getRewind();
+                if (is_int($rewind_to) && $rewind_to < $t) {
+                    if ($rewind_to < 0) $rewind_to = 0;
+                    while ($t > $rewind_to) {
+                        $t--;
+                        $prev = $tokens[$t];
+                        // indicate that other injectors should not process this token,
+                        // but we need to reprocess it
+                        unset($prev->skip[$i]);
+                        $prev->rewind = $i;
+                        if ($prev instanceof HTMLPurifier_Token_Start) array_pop($this->stack);
+                        elseif ($prev instanceof HTMLPurifier_Token_End) $this->stack[] = $prev->start;
+                    }
+                }
+                $i = false;
+            }
+
+            // handle case of document end
+            if (!isset($tokens[$t])) {
+                // kill processing if stack is empty
+                if (empty($this->stack)) break;
+
+                // peek
+                $top_nesting = array_pop($this->stack);
+                $this->stack[] = $top_nesting;
+
+                // send error
+                if ($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
+                $tokens[] = new HTMLPurifier_Token_End($top_nesting->name);
+
+                // punt!
+                $reprocess = true;
+                continue;
+            }
+
+            $token = $tokens[$t];
+
+            //echo '<br>'; printTokens($tokens, $t); printTokens($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[$i])) continue;
+                        if ($token->rewind !== null && $token->rewind !== $i) continue;
+                        $injector->handleText($token);
+                        $this->processToken($token, $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);
+                $ok = true;
+            } elseif ($type && $type !== 'empty' && $token instanceof HTMLPurifier_Token_Empty) {
+                // claims to be empty but really is a start tag
+                $this->swap(new HTMLPurifier_Token_End($token->name));
+                $this->insertBefore(new HTMLPurifier_Token_Start($token->name, $token->attr));
+                // 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)) {
+
+                    $parent = array_pop($this->stack);
+                    $this->stack[] = $parent;
+
+                    if (isset($definition->info[$parent->name])) {
+                        $elements = $definition->info[$parent->name]->child->getAllowedElements($config);
+                        $autoclose = !isset($elements[$token->name]);
+                    } else {
+                        $autoclose = false;
+                    }
+
+                    if ($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);
+                        $parent_elements = $definition->info[$parent->name]->child->getAllowedElements($config);
+                        if (isset($elements[$token->name]) && isset($parent_elements[$wrapname])) {
+                            $newtoken = new HTMLPurifier_Token_Start($wrapname);
+                            $this->insertBefore($newtoken);
+                            $reprocess = true;
+                            continue;
+                        }
+                    }
+
+                    $carryover = false;
+                    if ($autoclose && $definition->info[$parent->name]->formatting) {
+                        $carryover = true;
+                    }
+
+                    if ($autoclose) {
+                        // errors need to be updated
+                        $new_token = new HTMLPurifier_Token_End($parent->name);
+                        $new_token->start = $parent;
+                        if ($carryover) {
+                            $element = clone $parent;
+                            $element->armor['MakeWellFormed_TagClosedError'] = true;
+                            $element->carryover = true;
+                            $this->processToken(array($new_token, $token, $element));
+                        } else {
+                            $this->insertBefore($new_token);
+                        }
+                        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);
+                            }
+                        }
+                        $reprocess = true;
+                        continue;
+                    }
+
+                }
+                $ok = true;
+            }
+
+            if ($ok) {
+                foreach ($this->injectors as $i => $injector) {
+                    if (isset($token->skip[$i])) continue;
+                    if ($token->rewind !== null && $token->rewind !== $i) continue;
+                    $injector->handleElement($token);
+                    $this->processToken($token, $i);
+                    $reprocess = true;
+                    break;
+                }
+                if (!$reprocess) {
+                    // ah, nothing interesting happened; do normal processing
+                    $this->swap($token);
+                    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');
+                    $this->swap(new HTMLPurifier_Token_Text(
+                        $generator->generateFromToken($token)
+                    ));
+                } else {
+                    $this->remove();
+                    if ($e) $e->send(E_WARNING, 'Strategy_MakeWellFormed: Unnecessary end tag removed');
+                }
+                $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[$i])) continue;
+                    if ($token->rewind !== null && $token->rewind !== $i) continue;
+                    $injector->handleEnd($token);
+                    $this->processToken($token, $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) {
+                    $this->swap(new HTMLPurifier_Token_Text(
+                        $generator->generateFromToken($token)
+                    ));
+                    if ($e) $e->send(E_WARNING, 'Strategy_MakeWellFormed: Stray end tag to text');
+                } else {
+                    $this->remove();
+                    if ($e) $e->send(E_WARNING, 'Strategy_MakeWellFormed: Stray end tag removed');
+                }
+                $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 $j == 0, i.e. the current ending tag, from
+                    // the errors...
+                    if (!isset($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) {
+                    $element = clone $skipped_tags[$j];
+                    $element->carryover = true;
+                    $element->armor['MakeWellFormed_TagClosedError'] = true;
+                    $replace[] = $element;
+                }
+            }
+            $this->processToken($replace);
+            $reprocess = true;
+            continue;
+        }
+
+        $context->destroy('CurrentNesting');
+        $context->destroy('InputTokens');
+        $context->destroy('InputIndex');
+        $context->destroy('CurrentToken');
+
+        unset($this->injectors, $this->stack, $this->tokens, $this->t);
+        return $tokens;
+    }
+
+    /**
+     * 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 $token Token substitution value
+     * @param $injector Injector that performed the substitution; default is if
+     *        this is not an injector related operation.
+     */
+    protected function processToken($token, $injector = -1) {
+
+        // normalize forms of token
+        if (is_object($token)) $token = array(1, $token);
+        if (is_int($token))    $token = array($token);
+        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);
+        $old = array_splice($this->tokens, $this->t, $delete, $token);
+
+        if ($injector > -1) {
+            // determine appropriate skips
+            $oldskip = isset($old[0]) ? $old[0]->skip : array();
+            foreach ($token as $object) {
+                $object->skip = $oldskip;
+                $object->skip[$injector] = true;
+            }
+        }
+
+    }
+
+    /**
+     * Inserts a token before the current token. Cursor now points to this token
+     */
+    private function insertBefore($token) {
+        array_splice($this->tokens, $this->t, 0, array($token));
+    }
+
+    /**
+     * Removes current token. Cursor now points to new token occupying previously
+     * occupied space.
+     */
+    private function remove() {
+        array_splice($this->tokens, $this->t, 1);
+    }
+
+    /**
+     * Swap current token with new token. Cursor points to new token (no change).
+     */
+    private function swap($token) {
+        $this->tokens[$this->t] = $token;
+    }
+
+}
+
+// vim: et sw=4 sts=4