Create a tempnam substitute that safely creates files with a given extension.

modules/gallery/controllers/quick.php

@@ -36,8 +36,8 @@ class Quick_Controller extends Controller {
     }
 
     if ($degrees) {
-      $tmpfile = tempnam(TMPPATH, "rotate") . "." .
-        pathinfo($item->file_path(), PATHINFO_EXTENSION);
+      $tmpfile = system::tempnam(TMPPATH, "rotate",
+        "." . pathinfo($item->file_path(), PATHINFO_EXTENSION));
       gallery_graphics::rotate($item->file_path(), $tmpfile, array("degrees" => $degrees), $item);
       $item->set_data_file($tmpfile);
       $item->save();

modules/gallery/helpers/system.php

@@ -40,4 +40,29 @@ class system_Core {
     }
     return null;
   }
+
+  /**
+   * Create a file with a unique file name.
+   * This helper is similar to the built-in tempnam, except that it supports an optional postfix.
+   */
+  static function tempnam($dir = TMPPATH, $prefix = "", $postfix = "") {
+    return self::_tempnam($dir, $prefix, $postfix, "tempnam");
+  }
+
+  // This helper provides a dependency-injected implementation of tempnam.
+  static function _tempnam($dir, $prefix, $postfix, $builtin) {
+    $success = false;
+    do {
+      $basename = call_user_func($builtin, $dir, $prefix);
+      if (!$basename) {
+        return false;
+      }
+      $filename = $basename . $postfix;
+      $success = !file_exists($filename) && @rename($basename, $filename);
+      if (!$success) {
+        @unlink($basename);
+      }
+    } while (!$success);
+    return $filename;
+  }
 }

modules/gallery/tests/Mock_Built_In.php

@@ -0,0 +1,39 @@
+<?php defined("SYSPATH") or die("No direct script access.");
+/**
+ * Gallery - a web based photo album viewer and editor
+ * Copyright (C) 2011 Chad Parry
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or (at
+ * your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful, but
+ * WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin Street - Fifth Floor, Boston, MA  02110-1301, USA.
+ */
+/**
+ * Deterministic replacement for the built-in tempnam function.
+ * This is useful in unit tests where a dependency on tempnam needs to be mocked.
+ */
+class Mock_Built_In {
+  private $nonces;
+
+  function __construct() {
+    $this->nonces = func_get_args();
+  }
+
+  function _tempnam($dir, $prefix) {
+    if (empty($this->nonces))
+      return false;
+    $filename = "$dir/$prefix" . array_shift($this->nonces);
+    if (!touch($filename))
+      return false;
+    return $filename;
+  }
+}

modules/gallery/tests/System_Helper_Test.php

@@ -0,0 +1,49 @@
+<?php defined("SYSPATH") or die("No direct script access.");
+/**
+ * Gallery - a web based photo album viewer and editor
+ * Copyright (C) 2011 Chad Parry
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or (at
+ * your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful, but
+ * WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin Street - Fifth Floor, Boston, MA  02110-1301, USA.
+ */
+class System_Helper_Test extends Gallery_Unit_Test_Case {
+  public function tempnam_random_test() {
+    $filename = system::tempnam(TMPPATH, "file", ".ext");
+    $this->assert_true(file_exists($filename), "File not created");
+    unlink($filename);
+  }
+
+  public function tempnam_collision_test() {
+    require_once('Mock_Built_In.php');
+    $existing = TMPPATH . "/file1.ext";
+    $available = TMPPATH . "/file2.ext";
+    touch($existing);
+    $filename = system::_tempnam(TMPPATH, "file", ".ext",
+                                 array(new Mock_Built_In("1", "2"), "_tempnam"));
+    unlink($existing);
+    $this->assert_true(file_exists($filename), "File not created");
+    unlink($filename);
+    $this->assert_equal($available, $filename, "Incorrect filename created");
+  }
+
+  public function tempnam_abort_test() {
+    require_once('Mock_Built_In.php');
+    $filename = system::_tempnam(TMPPATH, "file", ".ext",
+                                 array(new Mock_Built_In(), "_tempnam"));
+    if ($filename) {
+      @unlink($filename);
+    }
+    $this->assert_false($filename, "Operation not aborted");
+  }
+}