Use PEAR Text_Figlet to render figlet fonts

Summary:
Ref T7785. Makes Figlet available without installing the `figlet` package.

The PEAR Text_Figlet code is really sketchy and includes this API, which is quite marvelous:

```
    function loadFont($filename, $loadgerman = true)
```

At some point, this should probably be rewritten into a modern style, but it's not trivial since the figlet file format and rendering engine are somewhat complicated. I made some adjustments:

  - Broke the dependency on the PEAR core.
  - Prevented it from doing any wrong HTML escaping.
  - Looked through it for any glaring security or correctness problems.

This code isn't very pretty or modern, but as far as I can tell it's safe and does render Figlet fonts in a reasonable way.

Test Plan: {F803268}

Reviewers: chad

Reviewed By: chad

Maniphest Tasks: T9408, T7785

Differential Revision: https://secure.phabricator.com/D14102

externals/pear-figlet/Text/Figlet.php

@@ -15,7 +15,6 @@
 * @version  CVS: $Id$
 * @link     http://pear.php.net/package/Text_Figlet
 */
-require_once 'PEAR.php';
 
 /**
 * ASCII art text creation
@@ -113,22 +112,9 @@ function loadFont($filename, $loadgerman = true)
     {
         $this->font = array();
         if (!file_exists($filename)) {
-            //if it does not exist, try the Text_Figlet data directory
-            include_once 'PEAR/Config.php';
-
-            $config  = PEAR_Config::singleton();
-            $fontdir = $config->get('data_dir') . '/Text_Figlet/fonts/';
-
-            //only for filenames without path separators
-            if (strpos($filename, '/') === false
-                && file_exists($fontdir . $filename)
-            ) {
-                $filename = $fontdir . $filename;
-            } else {
-                return PEAR::raiseError('Figlet font file "'
-                                        . $filename
-                                        . '" cannot be found', 1);
-            }
+          return self::raiseError('Figlet font file "'
+                                  . $filename
+                                  . '" cannot be found', 1);
         }
 
         $this->font_comment = '';
@@ -139,7 +125,7 @@ function loadFont($filename, $loadgerman = true)
             $compressed = true;
 
             if (!function_exists('gzcompress')) {
-                return PEAR::raiseError('Cannot load gzip compressed fonts since'
+                return self::raiseError('Cannot load gzip compressed fonts since'
                                         . ' gzcompress() is not available.',
                                         3);
             }
@@ -148,29 +134,29 @@ function loadFont($filename, $loadgerman = true)
         }
 
         if (!($fp = fopen($filename, 'rb'))) {
-            return PEAR::raiseError('Cannot open figlet font file ' . $filename, 2);
+            return self::raiseError('Cannot open figlet font file ' . $filename, 2);
         }
 
         if (!$compressed) {
             /* ZIPed font */
             if (fread($fp, 2) == 'PK') {
                 if (!function_exists('zip_open')) {
-                    return PEAR::raiseError('Cannot load ZIP compressed fonts since'
+                    return self::raiseError('Cannot load ZIP compressed fonts since'
                                             . ' ZIP PHP extension is not available.',
                                             5);
                 }
 
                 fclose($fp);
 
                 if (!($fp = zip_open($filename))) {
-                    return PEAR::raiseError('Cannot open figlet font file ' . $filename, 2);
+                    return self::raiseError('Cannot open figlet font file ' . $filename, 2);
                 }
 
                 $name = zip_entry_name(zip_read($fp));
                 zip_close($fp);
 
                 if (!($fp = fopen('zip://' . realpath($filename) . '#' . $name, 'rb'))) {
-                    return PEAR::raiseError('Cannot open figlet font file ' . $filename, 2);
+                    return self::raiseError('Cannot open figlet font file ' . $filename, 2);
                 }
 
                 $compressed = true;
@@ -193,7 +179,7 @@ function loadFont($filename, $loadgerman = true)
         $header = explode(' ', fgets($fp, 2048));
 
         if (substr($header[0], 0, 5) <> 'flf2a') {
-            return PEAR::raiseError('Unknown FIGlet font format.', 4);
+            return self::raiseError('Unknown FIGlet font format.', 4);
         }
 
         @list ($this->hardblank, $this->height,,,
@@ -381,9 +367,9 @@ function lineEcho($str, $inhtml = false)
         $str   = strtr(implode("\n", $out), $trans);
 
         if ($inhtml) {
-            return '<nobr>'.
-                   nl2br(str_replace(' ', '&nbsp;', htmlspecialchars($str))).
-                   '</nobr>';
+          self::raiseError(
+            'Do not use the HTML escaping provided by this class in '.
+            'a Phabricator context.');
         }
 
         return $str;
@@ -506,5 +492,9 @@ function _skip(&$fp)
 
         return true;
     }
+
+
+  private static function raiseError($message, $code = 1) {
+    throw new Exception($message);
+  }
 }
-?>

src/infrastructure/markup/interpreter/PhabricatorRemarkupFigletBlockInterpreter.php

@@ -7,41 +7,59 @@ public function getInterpreterName() {
     return 'figlet';
   }
 
+  /**
+   * @phutil-external-symbol class Text_Figlet
+   */
   public function markupContent($content, array $argv) {
-    if (!Filesystem::binaryExists('figlet')) {
-      return $this->markupError(
-        pht(
-          'Unable to locate the `%s` binary. Install figlet.',
-          'figlet'));
-    }
+    $map = self::getFigletMap();
 
-    $font = idx($argv, 'font', 'standard');
-    $safe_font = preg_replace('/[^0-9a-zA-Z-_.]/', '', $font);
-    $future = id(new ExecFuture('figlet -f %s', $safe_font))
-      ->setTimeout(15)
-      ->write(trim($content, "\n"));
+    $font = idx($argv, 'font');
+    $font = phutil_utf8_strtolower($font);
+    if (empty($map[$font])) {
+      $font = 'standard';
+    }
 
-    list($err, $stdout, $stderr) = $future->resolve();
+    $root = dirname(phutil_get_library_root('phabricator'));
+    require_once $root.'/externals/pear-figlet/Text/Figlet.php';
 
-    if ($err) {
-      return $this->markupError(
-        pht(
-          'Execution of `%s` failed: %s',
-          'figlet',
-          $stderr));
-    }
+    $figlet = new Text_Figlet();
+    $figlet->loadFont($map[$font]);
 
+    $result = $figlet->lineEcho($content);
 
     if ($this->getEngine()->isTextMode()) {
-      return $stdout;
+      return $result;
     }
 
     return phutil_tag(
       'div',
       array(
         'class' => 'PhabricatorMonospaced remarkup-figlet',
       ),
-      $stdout);
+      $result);
+  }
+
+  private static function getFigletMap() {
+    $root = dirname(phutil_get_library_root('phabricator'));
+
+    $dirs = array(
+      $root.'/externals/figlet/fonts/',
+      $root.'/externals/pear-figlet/fonts/',
+      $root.'/resources/figlet/custom/',
+    );
+
+    $map = array();
+    foreach ($dirs as $dir) {
+      foreach (Filesystem::listDirectory($dir, false) as $file) {
+        if (preg_match('/\.flf\z/', $file)) {
+          $name = phutil_utf8_strtolower($file);
+          $name = preg_replace('/\.flf\z/', '', $name);
+          $map[$name] = $dir.$file;
+        }
+      }
+    }
+
+    return $map;
   }
 
 }