prepare to tag v0.7.10

Add GD extension to the composer requiremets

.gitignore

@@ -11,3 +11,6 @@ vendor
 
 # Build and test
 build/
+
+# Mac OS
+.DS_Store

.travis.yml

@@ -76,6 +76,7 @@ script:
     
     # Run validation & publish
     #- make phpunit
+    - composer validate
     - phpunit
     #- make phpcs
 

CAsciiArt.php

@@ -175,7 +175,7 @@ class CAsciiArt
      */
     public function getLuminance($red, $green, $blue)
     {
-        switch($this->luminanceStrategy) {
+        switch ($this->luminanceStrategy) {
             case 1:
                 $luminance = ($red * 0.2126 + $green * 0.7152 + $blue * 0.0722) / 255;
                 break;

CCache.php

@@ -0,0 +1,107 @@
+<?php
+/**
+ * Deal with the cache directory and cached items.
+ *
+ */
+class CCache
+{
+    /**
+     * Path to the cache directory.
+     */
+    private $path;
+
+
+
+    /**
+     * Set the path to the cache dir which must exist.
+     *
+     * @param string path to the cache dir.
+     *
+     * @throws Exception when $path is not a directory.
+     *
+     * @return $this
+     */
+    public function setDir($path)
+    {
+        if (!is_dir($path)) {
+            throw new Exception("Cachedir is not a directory.");
+        }
+
+        $this->path = $path;
+
+        return $this;
+    }
+
+
+
+    /**
+     * Get the path to the cache subdir and try to create it if its not there.
+     *
+     * @param string $subdir name of subdir
+     * @param array  $create default is to try to create the subdir
+     *
+     * @return string | boolean as real path to the subdir or
+     *                          false if it does not exists
+     */
+    public function getPathToSubdir($subdir, $create = true)
+    {
+        $path = realpath($this->path . "/" . $subdir);
+
+        if (is_dir($path)) {
+            return $path;
+        }
+
+        if ($create && is_writable($this->path)) {
+            $path = $this->path . "/" . $subdir;
+
+            if (mkdir($path)) {
+                return realpath($path);
+            }
+        }
+
+        return false;
+    }
+
+
+
+    /**
+     * Get status of the cache subdir.
+     *
+     * @param string $subdir name of subdir
+     *
+     * @return string with status
+     */
+    public function getStatusOfSubdir($subdir)
+    {
+        $path = realpath($this->path . "/" . $subdir);
+
+        $exists = is_dir($path);
+        $res  = $exists ? "exists" : "does not exist";
+        
+        if ($exists) {
+            $res .= is_writable($path) ? ", writable" : ", not writable";
+        }
+
+        return $res;
+    }
+
+
+
+    /**
+     * Remove the cache subdir.
+     *
+     * @param string $subdir name of subdir
+     *
+     * @return null | boolean true if success else false, null if no operation
+     */
+    public function removeSubdir($subdir)
+    {
+        $path = realpath($this->path . "/" . $subdir);
+
+        if (is_dir($path)) {
+            return rmdir($path);
+        }
+
+        return null;
+    }
+}

CImage.php

@@ -344,20 +344,27 @@ class CImage
 
 
     /**
-    * Calculate target dimension for image when using fill-to-fit resize strategy.
-    */
+     * Calculate target dimension for image when using fill-to-fit resize strategy.
+     */
     private $fillWidth;
     private $fillHeight;
 
 
 
     /**
-    * Allow remote file download, default is to disallow remote file download.
-    */
+     * Allow remote file download, default is to disallow remote file download.
+     */
     private $allowRemote = false;
 
 
 
+    /**
+     * Path to cache for remote download.
+     */
+    private $remoteCache;
+
+
+
     /**
      * Pattern to recognize a remote file.
      */
@@ -512,13 +519,15 @@ class CImage
      * Allow or disallow remote image download.
      *
      * @param boolean $allow   true or false to enable and disable.
+     * @param string  $cache   path to cache dir.
      * @param string  $pattern to use to detect if its a remote file.
      *
      * @return $this
      */
-    public function setRemoteDownload($allow, $pattern = null)
+    public function setRemoteDownload($allow, $cache, $pattern = null)
     {
         $this->allowRemote = $allow;
+        $this->remoteCache = $cache;
         $this->remotePattern = is_null($pattern) ? $this->remotePattern : $pattern;
 
         $this->log(
@@ -650,21 +659,12 @@ class CImage
         }
 
         $remote = new CRemoteImage();
-        $cache  = $this->saveFolder . "/remote/";
 
-        if (!is_dir($cache)) {
-            if (!is_writable($this->saveFolder)) {
-                throw new Exception("Can not create remote cache, cachefolder not writable.");
-            }
-            mkdir($cache);
-            $this->log("The remote cache does not exists, creating it.");
-        }
-
-        if (!is_writable($cache)) {
+        if (!is_writable($this->remoteCache)) {
             $this->log("The remote cache is not writable.");
         }
 
-        $remote->setCache($cache);
+        $remote->setCache($this->remoteCache);
         $remote->useCache($this->useCache);
         $src = $remote->download($src);
 

CRemoteImage.php

@@ -101,7 +101,7 @@ class CRemoteImage
      */
     public function setCache($path)
     {
-        $this->saveFolder = $path;
+        $this->saveFolder = rtrim($path, "/") . "/";
         return $this;
     }
 
@@ -147,7 +147,12 @@ class CRemoteImage
      */
     public function setHeaderFields()
     {
-        $this->http->setHeader("User-Agent", "CImage/0.7.2 (PHP/". phpversion() . " cURL)");
+        $cimageVersion = "CImage";
+        if (defined("CIMAGE_USER_AGENT")) {
+            $cimageVersion = CIMAGE_USER_AGENT;
+        }
+        
+        $this->http->setHeader("User-Agent", "$cimageVersion (PHP/". phpversion() . " cURL)");
         $this->http->setHeader("Accept", "image/jpeg,image/png,image/gif");
 
         if ($this->useCache) {

README.md

@@ -46,14 +46,14 @@ There are several ways of installing. You either install the whole project which
 
 The [sourcode is available on GitHub](https://github.com/mosbth/cimage). Clone, fork or [download as zip](https://github.com/mosbth/cimage/archive/master.zip). 
 
-**Latest stable version is v0.7.8 released 2015-12-06.**
+**Latest stable version is v0.7.9 released 2015-12-07.**
 
 I prefer cloning like this. Do switch to the latest stable version.
 
 ```bash
 git clone git://github.com/mosbth/cimage.git
 cd cimage
-git checkout v0.7.8
+git checkout v0.7.9
 ```
 
 Make the cache-directory writable by the webserver.
@@ -76,7 +76,7 @@ There are some all-included bundles of `img.php` that can be downloaded and used
 Dowload the version of your choice like this.
 
 ```bash
-wget https://raw.githubusercontent.com/mosbth/cimage/v0.7.8/webroot/imgp.php
+wget https://raw.githubusercontent.com/mosbth/cimage/v0.7.9/webroot/imgp.php
 ```
 
 Open up the file in your editor and edit the array `$config`. Ensure that the paths to the image directory and the cache directory matches your environment, or create an own config-file for the script.

REVISION.md

@@ -5,6 +5,22 @@ Revision history
 [![Build Status](https://scrutinizer-ci.com/g/mosbth/cimage/badges/build.png?b=master)](https://scrutinizer-ci.com/g/mosbth/cimage/build-status/master)
 
 
+v0.7.10 (2016-04-01)
+-------------------------------------
+
+* Add backup option for images `src-alt`, #141.
+* Add require of ext-gd in composer.json, #133.
+* Fix strict mode only reporting 404 when failure, #127.
+
+
+v0.7.9 (2015-12-07)
+-------------------------------------
+
+* Strict mode only reporting 404 when failure, #127.
+* Added correct CImage version to remote agent string, #131.
+* Adding CCache to improve cache handling of caching for dummy, remote and srgb. #130.
+
+
 v0.7.8 (2015-12-06)
 -------------------------------------
 

bin/create-img-single.bash

@@ -39,6 +39,7 @@ $ECHO "\n CRemoteImage.php"
 $ECHO "\n CWhitelist.php"
 $ECHO "\n CAsciiArt.php"
 $ECHO "\n CImage.php"
+$ECHO "\n CCache.php"
 $ECHO "\n webroot/img.php"
 $ECHO "\n"
 $ECHO "\n'$TARGET_D' is for development mode."
@@ -74,6 +75,9 @@ $ECHO "$NEWLINES" | tee -a $TARGET_D $TARGET_P $TARGET_S > /dev/null
 tail -n +2 CImage.php | tee -a $TARGET_D $TARGET_P $TARGET_S > /dev/null
 $ECHO "$NEWLINES" | tee -a $TARGET_D $TARGET_P $TARGET_S > /dev/null
 
+tail -n +2 CCache.php | tee -a $TARGET_D $TARGET_P $TARGET_S > /dev/null
+$ECHO "$NEWLINES" | tee -a $TARGET_D $TARGET_P $TARGET_S > /dev/null
+
 tail -n +2 webroot/img.php | tee -a $TARGET_D $TARGET_P $TARGET_S > /dev/null
 $ECHO "$NEWLINES" | tee -a $TARGET_D $TARGET_P $TARGET_S > /dev/null
 

composer.json

@@ -18,7 +18,11 @@
         "docs": "http://dbwebb.se/opensource/cimage"
     },
     "require": {
-        "php": ">=5.3"
+        "php": ">=5.3",
+        "ext-gd": "*"
+    },
+    "suggest": {
+        "ext-exif": "*"
     },
     "autoload": {
         "classmap": [
@@ -26,7 +30,8 @@
             "CHttpGet.php",
             "CRemoteImage.php",
             "CWhitelist.php",
-            "CAsciiArt.php"
+            "CAsciiArt.php",
+            "CCache.php"
         ]
     }
 }

test/CCacheTest.php

@@ -0,0 +1,68 @@
+<?php
+/**
+ * A testclass
+ *
+ */
+class CCacheTest extends \PHPUnit_Framework_TestCase
+{
+    /**
+     * Test
+     *
+     * @return void
+     */
+    public function testSetCacheDir()
+    {
+        $cache = new CCache();
+        $cache->setDir(CACHE_PATH);
+
+        $exp = "exists, writable";
+        $res = $cache->getStatusOfSubdir("");
+        $this->assertEquals($exp, $res, "Status of cache dir missmatch.");
+    }
+
+
+
+    /**
+     * Test
+     *
+     * @expectedException Exception
+     *
+     * @return void
+     */
+    public function testSetWrongCacheDir()
+    {
+        $cache = new CCache();
+        $cache->setDir(CACHE_PATH . "/NO_EXISTS");
+    }
+
+
+
+    /**
+     * Test
+     *
+     * @return void
+     */
+    public function testCreateSubdir()
+    {
+        $cache = new CCache();
+        $cache->setDir(CACHE_PATH);
+        
+        $subdir = "__test__";
+        $cache->removeSubdir($subdir);
+        
+        $exp = "does not exist";
+        $res = $cache->getStatusOfSubdir($subdir, false);
+        $this->assertEquals($exp, $res, "Subdir should not be created.");
+        
+        $res = $cache->getPathToSubdir($subdir);
+        $exp = realpath(CACHE_PATH . "/$subdir");
+        $this->assertEquals($exp, $res, "Subdir path missmatch.");
+
+        $exp = "exists, writable";
+        $res = $cache->getStatusOfSubdir($subdir);
+        $this->assertEquals($exp, $res, "Subdir should exist.");
+
+        $res = $cache->removeSubdir($subdir);
+        $this->assertTrue($res, "Remove subdir.");
+    }
+}

test/CImageDummyTest.php

@@ -5,6 +5,57 @@
  */
 class CImageDummyTest extends \PHPUnit_Framework_TestCase
 {
+    const DUMMY = "__dummy__";
+    private $cachepath;
+
+
+
+    /**
+     * Setup environment
+     *
+     * @return void
+     */
+    protected function setUp()
+    {
+        $cache = new CCache();
+        $cache->setDir(CACHE_PATH);
+        $this->cachepath = $cache->getPathToSubdir(self::DUMMY);
+    }
+
+
+
+    /**
+     * Clean up cache dir content.
+     *
+     * @return void
+     */
+    protected function removeFilesInCacheDir()
+    {
+        $files = glob($this->cachepath . "/*");
+        foreach ($files as $file) {
+            if (is_file($file)) {
+                unlink($file);
+            }
+        }
+    }
+
+
+
+    /**
+     * Teardown environment
+     *
+     * @return void
+     */
+    protected function tearDown()
+    {
+        $cache = new CCache();
+        $cache->setDir(CACHE_PATH);
+        $this->removeFilesInCacheDir();
+        $cache->removeSubdir(self::DUMMY);
+    }
+
+
+
     /**
      * Test
      *
@@ -14,15 +65,15 @@ class CImageDummyTest extends \PHPUnit_Framework_TestCase
     {
         $img = new CImage();
 
-        $img->setSaveFolder(CACHE_PATH . "/dummy");
-        $img->setSource('dummy', CACHE_PATH . "/dummy");
+        $img->setSaveFolder($this->cachepath);
+        $img->setSource(self::DUMMY, $this->cachepath);
         $img->createDummyImage();
         $img->generateFilename(null, false);
         $img->save(null, null, false);
 
         $filename = $img->getTarget();
 
-        $this->assertEquals(basename($filename), "dummy_100_100", "Filename not as expected on dummy image.");
+        $this->assertEquals(basename($filename), self::DUMMY . "_100_100", "Filename not as expected on dummy image.");
     }
 
 
@@ -36,14 +87,14 @@ class CImageDummyTest extends \PHPUnit_Framework_TestCase
     {
         $img = new CImage();
 
-        $img->setSaveFolder(CACHE_PATH . "/dummy");
-        $img->setSource('dummy', CACHE_PATH . "/dummy");
+        $img->setSaveFolder($this->cachepath);
+        $img->setSource(self::DUMMY, $this->cachepath);
         $img->createDummyImage(200, 400);
         $img->generateFilename(null, false);
         $img->save(null, null, false);
 
         $filename = $img->getTarget();
 
-        $this->assertEquals(basename($filename), "dummy_200_400", "Filename not as expected on dummy image.");
+        $this->assertEquals(basename($filename), self::DUMMY . "_200_400", "Filename not as expected on dummy image.");
     }
 }

test/CImageRemoteDownloadTest.php

@@ -61,7 +61,7 @@ class CImageRemoteDownloadTest extends \PHPUnit_Framework_TestCase
     public function testAllowRemoteDownloadDefaultPatternValid($source)
     {
         $img = new CImage();
-        $img->setRemoteDownload(true);
+        $img->setRemoteDownload(true, "");
         
         $res = $img->isRemoteSource($source);
         $this->assertTrue($res, "Should be a valid remote source: '$source'.");
@@ -79,7 +79,7 @@ class CImageRemoteDownloadTest extends \PHPUnit_Framework_TestCase
     public function testAllowRemoteDownloadDefaultPatternInvalid($source)
     {
         $img = new CImage();
-        $img->setRemoteDownload(true);
+        $img->setRemoteDownload(true, "");
         
         $res = $img->isRemoteSource($source);
         $this->assertFalse($res, "Should not be a valid remote source: '$source'.");

test/CImageSRGBTest.php

@@ -38,7 +38,7 @@ class CImageSRGBTest extends \PHPUnit_Framework_TestCase
         $img = new CImage();
 
         $filename = $img->convert2sRGBColorSpace(
-            'car.png', 
+            'car.png',
             IMAGE_PATH,
             $this->cache,
             $this->srgbColorProfile
@@ -63,8 +63,8 @@ class CImageSRGBTest extends \PHPUnit_Framework_TestCase
         $img = new CImage();
 
         $filename = $img->convert2sRGBColorSpace(
-            'car.jpg', 
-            IMAGE_PATH, 
+            'car.jpg',
+            IMAGE_PATH,
             $this->cache,
             $this->srgbColorProfile
         );

webroot/img.php

@@ -8,7 +8,10 @@
  *
  */
 
-$version = "v0.7.8 (2015-12-06)";
+$version = "v0.7.10 (2016-04-01)";
+
+// For CRemoteImage
+define("CIMAGE_USER_AGENT", "CImage/$version");
 
 
 
@@ -27,17 +30,21 @@ function errorPage($msg, $type = 500)
     switch ($type) {
         case 403:
             $header = "403 Forbidden";
-        break;
+            break;
         case 404:
             $header = "404 Not Found";
-        break;
+            break;
         default:
             $header = "500 Internal Server Error";
     }
 
+    if ($mode == "strict") {
+        $header = "404 Not Found";
+    }
+
     header("HTTP/1.0 $header");
 
-    if ($mode == 'development') {
+    if ($mode == "development") {
         die("[img.php] $msg");
     }
 
@@ -56,8 +63,9 @@ set_exception_handler(function ($exception) {
         . $exception->getMessage()
         . "</p><pre>"
         . $exception->getTraceAsString()
-        . "</pre>"
-    , 500);
+        . "</pre>",
+        500
+    );
 });
 
 
@@ -256,7 +264,7 @@ $pwd         = get(array('password', 'pwd'), null);
 // Check if passwords match, if configured to use passwords
 $passwordMatch = null;
 if ($pwd) {
-    switch($pwdType) {
+    switch ($pwdType) {
         case 'md5':
             $passwordMatch = ($pwdConfig === md5($pwd));
             break;
@@ -345,6 +353,16 @@ $img->setVerbose($verbose || $verboseFile);
 
 
 
+/**
+ * Get the cachepath from config.
+ */
+$cachePath = getConfig('cache_path', __DIR__ . '/../cache/');
+$cache = new CCache();
+$cache->setDir($cachePath);
+
+
+
+
 /**
  * Allow or disallow remote download of images from other servers.
  * Passwords apply if used.
@@ -353,8 +371,10 @@ $img->setVerbose($verbose || $verboseFile);
 $allowRemote = getConfig('remote_allow', false);
 
 if ($allowRemote && $passwordMatch !== false) {
+    $cacheRemote = $cache->getPathToSubdir("remote");
+    
     $pattern = getConfig('remote_pattern', null);
-    $img->setRemoteDownload($allowRemote, $pattern);
+    $img->setRemoteDownload($allowRemote, $cacheRemote, $pattern);
 
     $whitelist = getConfig('remote_whitelist', null);
     $img->setRemoteHostWhitelist($whitelist);
@@ -389,18 +409,28 @@ if (isset($shortcut)
 $srcImage = urldecode(get('src'))
     or errorPage('Must set src-attribute.', 404);
 
+// Get settings for src-alt as backup image
+$srcAltImage = urldecode(get('src-alt', null));
+$srcAltConfig = getConfig('src_alt', null);
+if (empty($srcAltImage)) {
+    $srcAltImage = $srcAltConfig;
+}
+
 // Check for valid/invalid characters
 $imagePath           = getConfig('image_path', __DIR__ . '/img/');
 $imagePathConstraint = getConfig('image_path_constraint', true);
 $validFilename       = getConfig('valid_filename', '#^[a-z0-9A-Z-/_ \.:]+$#');
 
+// Source is remote
+$remoteSource = false;
+
 // Dummy image feature
 $dummyEnabled  = getConfig('dummy_enabled', true);
 $dummyFilename = getConfig('dummy_filename', 'dummy');
 $dummyImage = false;
 
 preg_match($validFilename, $srcImage)
-    or errorPage('Filename contains invalid characters.', 404);
+    or errorPage('Source filename contains invalid characters.', 404);
 
 if ($dummyEnabled && $srcImage === $dummyFilename) {
 
@@ -410,24 +440,47 @@ if ($dummyEnabled && $srcImage === $dummyFilename) {
 } elseif ($allowRemote && $img->isRemoteSource($srcImage)) {
 
     // If source is a remote file, ignore local file checks.
+    $remoteSource = true;
 
-} elseif ($imagePathConstraint) {
+} else {
 
-    // Check that the image is a file below the directory 'image_path'.
+    // Check if file exists on disk or try using src-alt
     $pathToImage = realpath($imagePath . $srcImage);
-    $imageDir    = realpath($imagePath);
 
-    is_file($pathToImage)
-        or errorPage(
-            'Source image is not a valid file, check the filename and that a
-            matching file exists on the filesystem.'
-        , 404);
+    if (!is_file($pathToImage) && !empty($srcAltImage)) {
+        // Try using the src-alt instead
+        $srcImage = $srcAltImage;
+        $pathToImage = realpath($imagePath . $srcImage);
+
+        preg_match($validFilename, $srcImage)
+            or errorPage('Source (alt) filename contains invalid characters.', 404);
+
+        if ($dummyEnabled && $srcImage === $dummyFilename) {
+            // Check if src-alt is the dummy image
+            $dummyImage = true;
+        }
+    }
+
+    if (!$dummyImage) {
+        is_file($pathToImage)
+            or errorPage(
+                'Source image is not a valid file, check the filename and that a
+                matching file exists on the filesystem.',
+                404
+            );
+    } 
+}
+
+if ($imagePathConstraint && !$dummyImage && !$remoteSource) {
+    // Check that the image is a file below the directory 'image_path'.
+    $imageDir = realpath($imagePath);
 
     substr_compare($imageDir, $pathToImage, 0, strlen($imageDir)) == 0
         or errorPage(
             'Security constraint: Source image is not below the directory "image_path"
-            as specified in the config file img_config.php.'
-        , 404);
+            as specified in the config file img_config.php.',
+            404
+        );
 }
 
 verbose("src = $srcImage");
@@ -940,14 +993,7 @@ verbose("alias = $alias");
 
 
 /**
- * Get the cachepath from config.
- */
-$cachePath = getConfig('cache_path', __DIR__ . '/../cache/');
-
-
-
-/**
- * Get the cachepath from config.
+ * Add cache control HTTP header.
  */
 $cacheControl = getConfig('cache_control', null);
 
@@ -961,11 +1007,8 @@ if ($cacheControl) {
 /**
  * Prepare a dummy image and use it as source image.
  */
-$dummyDir = getConfig('dummy_dir', $cachePath. "/" . $dummyFilename);
-
 if ($dummyImage === true) {
-    is_writable($dummyDir)
-        or verbose("dummy dir not writable = $dummyDir");
+    $dummyDir = $cache->getPathToSubdir("dummy");
 
     $img->setSaveFolder($dummyDir)
         ->setSource($dummyFilename, $dummyDir)
@@ -993,24 +1036,16 @@ if ($dummyImage === true) {
 /**
  * Prepare a sRGB version of the image and use it as source image.
  */
-$srgbDirName = "/srgb";
-$srgbDir     = realpath(getConfig('srgb_dir', $cachePath . $srgbDirName));
 $srgbDefault = getConfig('srgb_default', false);
 $srgbColorProfile = getConfig('srgb_colorprofile', __DIR__ . '/../icc/sRGB_IEC61966-2-1_black_scaled.icc');
 $srgb = getDefined('srgb', true, null);
 
 if ($srgb || $srgbDefault) {
 
-    if (!is_writable($srgbDir)) {
-        if (is_writable($cachePath)) {
-            mkdir($srgbDir);
-        }
-    }
-
     $filename = $img->convert2sRGBColorSpace(
         $srcImage,
         $imagePath,
-        $srgbDir,
+        $cache->getPathToSubdir("srgb"),
         $srgbColorProfile,
         $useCache
     );
@@ -1034,9 +1069,19 @@ if ($status) {
     $text .= "PHP version = " . PHP_VERSION . "\n";
     $text .= "Running on: " . $_SERVER['SERVER_SOFTWARE'] . "\n";
     $text .= "Allow remote images = $allowRemote\n";
-    $text .= "Cache writable = " . is_writable($cachePath) . "\n";
-    $text .= "Cache dummy writable = " . is_writable($dummyDir) . "\n";
-    $text .= "Cache srgb writable = " . is_writable($srgbDir) . "\n";
+
+    $res = $cache->getStatusOfSubdir("");
+    $text .= "Cache $res\n";
+
+    $res = $cache->getStatusOfSubdir("remote");
+    $text .= "Cache remote $res\n";
+
+    $res = $cache->getStatusOfSubdir("dummy");
+    $text .= "Cache dummy $res\n";
+
+    $res = $cache->getStatusOfSubdir("srgb");
+    $text .= "Cache srgb $res\n";
+
     $text .= "Alias path writable = " . is_writable($aliasPath) . "\n";
 
     $no = extension_loaded('exif') ? null : 'NOT';

webroot/img_config.php

@@ -13,8 +13,9 @@ return array(
      * Default values:
      *  mode: 'production'
      */
-     //'mode' => 'production', // 'development', 'strict'
-     //'mode' => 'development', // 'development', 'strict'
+     //'mode' => 'production',
+     //'mode' => 'development',
+     //'mode' => 'strict',
 
 
 
@@ -97,6 +98,20 @@ return array(
 
 
 
+    /**
+     * Use backup image if src-image is not found on disk. The backup image
+     * is only available for local images and based on wether the original
+     * image is found on disk or not. The backup image must be a local image
+     * or the dummy image.
+     *
+     * Default value:
+     *  src_alt:  null //disabled by default
+     */
+     //'src_alt' => 'car.png',
+     //'src_alt' => 'dummy',
+
+
+
     /**
      * A regexp for validating characters in the image or alias filename.
      *
@@ -124,17 +139,15 @@ return array(
 
       /**
        * Convert the image to srgb before processing. Saves the converted
-       * image in the sub cache dir. This option is default false but can
+       * image in a cache subdir 'srgb'. This option is default false but can
        * be changed to default true to do this conversion for all images.
        * This option requires PHP extension imagick and will silently fail
        * if that is not installed.
        *
        * Default value:
-       *  srgb_dir:          $cachePath/srgb
        *  srgb_default:      false
        *  srgb_colorprofile: __DIR__ . '/../icc/sRGB_IEC61966-2-1_black_scaled.icc'
        */
-       //'srgb_dir'  => __DIR__ . '/../cache/srgb/',
        //'srgb_default' => false,
        //'srgb_colorprofile' => __DIR__ . '/../icc/sRGB_IEC61966-2-1_black_scaled.icc',
 
@@ -170,30 +183,27 @@ return array(
 
      /**
       * The name representing a dummy image which is automatically created
-      * and stored at the defined path. The dummy image can then be used
-      * inplace of an original image as a placeholder.
-      * The dummy_dir must be writable and it defaults to a subdir of the
-      * cache directory.
-      * Write protect the dummy_dir to prevent creation of new dummy images,
-      * but continue to use the existing ones.
+      * and stored as a image in the dir CACHE_PATH/dummy. The dummy image
+      * can then be used as a placeholder image.
+      * The dir CACHE_PATH/dummy is automatically created when needed.
+      * Write protect the CACHE_PATH/dummy to prevent creation of new
+      * dummy images, but continue to use the existing ones.
       *
       * Default value:
       *  dummy_enabled:  true as default, disable dummy feature by setting
       *                  to false.
       *  dummy_filename: 'dummy' use this as ?src=dummy to create a dummy image.
-      *  dummy_dir:      Defaults to subdirectory of 'cache_path',
-      *                  named the same as 'dummy_filename'
       */
       //'dummy_enabled' => true,
       //'dummy_filename' => 'dummy',
-      //'dummy_dir' => 'some writable directory',
 
 
 
      /**
      * Check that the imagefile is a file below 'image_path' using realpath().
      * Security constraint to avoid reaching images outside image_path.
-     * This means that symbolic links to images outside the image_path will fail.
+     * This means that symbolic links to images outside the image_path will
+     * fail.
      *
      * Default value:
      *  image_path_constraint: true

webroot/imgd.php

@@ -430,7 +430,7 @@ class CRemoteImage
      */
     public function setCache($path)
     {
-        $this->saveFolder = $path;
+        $this->saveFolder = rtrim($path, "/") . "/";
         return $this;
     }
 
@@ -476,7 +476,12 @@ class CRemoteImage
      */
     public function setHeaderFields()
     {
-        $this->http->setHeader("User-Agent", "CImage/0.7.2 (PHP/". phpversion() . " cURL)");
+        $cimageVersion = "CImage";
+        if (defined("CIMAGE_USER_AGENT")) {
+            $cimageVersion = CIMAGE_USER_AGENT;
+        }
+        
+        $this->http->setHeader("User-Agent", "$cimageVersion (PHP/". phpversion() . " cURL)");
         $this->http->setHeader("Accept", "image/jpeg,image/png,image/gif");
 
         if ($this->useCache) {
@@ -880,7 +885,7 @@ class CAsciiArt
      */
     public function getLuminance($red, $green, $blue)
     {
-        switch($this->luminanceStrategy) {
+        switch ($this->luminanceStrategy) {
             case 1:
                 $luminance = ($red * 0.2126 + $green * 0.7152 + $blue * 0.0722) / 255;
                 break;
@@ -1263,20 +1268,27 @@ class CImage
 
 
     /**
-    * Calculate target dimension for image when using fill-to-fit resize strategy.
-    */
+     * Calculate target dimension for image when using fill-to-fit resize strategy.
+     */
     private $fillWidth;
     private $fillHeight;
 
 
 
     /**
-    * Allow remote file download, default is to disallow remote file download.
-    */
+     * Allow remote file download, default is to disallow remote file download.
+     */
     private $allowRemote = false;
 
 
 
+    /**
+     * Path to cache for remote download.
+     */
+    private $remoteCache;
+
+
+
     /**
      * Pattern to recognize a remote file.
      */
@@ -1431,13 +1443,15 @@ class CImage
      * Allow or disallow remote image download.
      *
      * @param boolean $allow   true or false to enable and disable.
+     * @param string  $cache   path to cache dir.
      * @param string  $pattern to use to detect if its a remote file.
      *
      * @return $this
      */
-    public function setRemoteDownload($allow, $pattern = null)
+    public function setRemoteDownload($allow, $cache, $pattern = null)
     {
         $this->allowRemote = $allow;
+        $this->remoteCache = $cache;
         $this->remotePattern = is_null($pattern) ? $this->remotePattern : $pattern;
 
         $this->log(
@@ -1569,21 +1583,12 @@ class CImage
         }
 
         $remote = new CRemoteImage();
-        $cache  = $this->saveFolder . "/remote/";
 
-        if (!is_dir($cache)) {
-            if (!is_writable($this->saveFolder)) {
-                throw new Exception("Can not create remote cache, cachefolder not writable.");
-            }
-            mkdir($cache);
-            $this->log("The remote cache does not exists, creating it.");
-        }
-
-        if (!is_writable($cache)) {
+        if (!is_writable($this->remoteCache)) {
             $this->log("The remote cache is not writable.");
         }
 
-        $remote->setCache($cache);
+        $remote->setCache($this->remoteCache);
         $remote->useCache($this->useCache);
         $src = $remote->download($src);
 
@@ -3694,6 +3699,115 @@ EOD;
 
 
 
+/**
+ * Deal with the cache directory and cached items.
+ *
+ */
+class CCache
+{
+    /**
+     * Path to the cache directory.
+     */
+    private $path;
+
+
+
+    /**
+     * Set the path to the cache dir which must exist.
+     *
+     * @param string path to the cache dir.
+     *
+     * @throws Exception when $path is not a directory.
+     *
+     * @return $this
+     */
+    public function setDir($path)
+    {
+        if (!is_dir($path)) {
+            throw new Exception("Cachedir is not a directory.");
+        }
+
+        $this->path = $path;
+
+        return $this;
+    }
+
+
+
+    /**
+     * Get the path to the cache subdir and try to create it if its not there.
+     *
+     * @param string $subdir name of subdir
+     * @param array  $create default is to try to create the subdir
+     *
+     * @return string | boolean as real path to the subdir or
+     *                          false if it does not exists
+     */
+    public function getPathToSubdir($subdir, $create = true)
+    {
+        $path = realpath($this->path . "/" . $subdir);
+
+        if (is_dir($path)) {
+            return $path;
+        }
+
+        if ($create && is_writable($this->path)) {
+            $path = $this->path . "/" . $subdir;
+
+            if (mkdir($path)) {
+                return realpath($path);
+            }
+        }
+
+        return false;
+    }
+
+
+
+    /**
+     * Get status of the cache subdir.
+     *
+     * @param string $subdir name of subdir
+     *
+     * @return string with status
+     */
+    public function getStatusOfSubdir($subdir)
+    {
+        $path = realpath($this->path . "/" . $subdir);
+
+        $exists = is_dir($path);
+        $res  = $exists ? "exists" : "does not exist";
+        
+        if ($exists) {
+            $res .= is_writable($path) ? ", writable" : ", not writable";
+        }
+
+        return $res;
+    }
+
+
+
+    /**
+     * Remove the cache subdir.
+     *
+     * @param string $subdir name of subdir
+     *
+     * @return null | boolean true if success else false, null if no operation
+     */
+    public function removeSubdir($subdir)
+    {
+        $path = realpath($this->path . "/" . $subdir);
+
+        if (is_dir($path)) {
+            return rmdir($path);
+        }
+
+        return null;
+    }
+}
+
+
+
 /**
  * Resize and crop images on the fly, store generated images in a cache.
  *
@@ -3703,7 +3817,10 @@ EOD;
  *
  */
 
-$version = "v0.7.8 (2015-12-06)";
+$version = "v0.7.10 (2016-04-01)";
+
+// For CRemoteImage
+define("CIMAGE_USER_AGENT", "CImage/$version");
 
 
 
@@ -3722,17 +3839,21 @@ function errorPage($msg, $type = 500)
     switch ($type) {
         case 403:
             $header = "403 Forbidden";
-        break;
+            break;
         case 404:
             $header = "404 Not Found";
-        break;
+            break;
         default:
             $header = "500 Internal Server Error";
     }
 
+    if ($mode == "strict") {
+        $header = "404 Not Found";
+    }
+
     header("HTTP/1.0 $header");
 
-    if ($mode == 'development') {
+    if ($mode == "development") {
         die("[img.php] $msg");
     }
 
@@ -3751,8 +3872,9 @@ set_exception_handler(function ($exception) {
         . $exception->getMessage()
         . "</p><pre>"
         . $exception->getTraceAsString()
-        . "</pre>"
-    , 500);
+        . "</pre>",
+        500
+    );
 });
 
 
@@ -3951,7 +4073,7 @@ $pwd         = get(array('password', 'pwd'), null);
 // Check if passwords match, if configured to use passwords
 $passwordMatch = null;
 if ($pwd) {
-    switch($pwdType) {
+    switch ($pwdType) {
         case 'md5':
             $passwordMatch = ($pwdConfig === md5($pwd));
             break;
@@ -4040,6 +4162,16 @@ $img->setVerbose($verbose || $verboseFile);
 
 
 
+/**
+ * Get the cachepath from config.
+ */
+$cachePath = getConfig('cache_path', __DIR__ . '/../cache/');
+$cache = new CCache();
+$cache->setDir($cachePath);
+
+
+
+
 /**
  * Allow or disallow remote download of images from other servers.
  * Passwords apply if used.
@@ -4048,8 +4180,10 @@ $img->setVerbose($verbose || $verboseFile);
 $allowRemote = getConfig('remote_allow', false);
 
 if ($allowRemote && $passwordMatch !== false) {
+    $cacheRemote = $cache->getPathToSubdir("remote");
+    
     $pattern = getConfig('remote_pattern', null);
-    $img->setRemoteDownload($allowRemote, $pattern);
+    $img->setRemoteDownload($allowRemote, $cacheRemote, $pattern);
 
     $whitelist = getConfig('remote_whitelist', null);
     $img->setRemoteHostWhitelist($whitelist);
@@ -4084,18 +4218,28 @@ if (isset($shortcut)
 $srcImage = urldecode(get('src'))
     or errorPage('Must set src-attribute.', 404);
 
+// Get settings for src-alt as backup image
+$srcAltImage = urldecode(get('src-alt', null));
+$srcAltConfig = getConfig('src_alt', null);
+if (empty($srcAltImage)) {
+    $srcAltImage = $srcAltConfig;
+}
+
 // Check for valid/invalid characters
 $imagePath           = getConfig('image_path', __DIR__ . '/img/');
 $imagePathConstraint = getConfig('image_path_constraint', true);
 $validFilename       = getConfig('valid_filename', '#^[a-z0-9A-Z-/_ \.:]+$#');
 
+// Source is remote
+$remoteSource = false;
+
 // Dummy image feature
 $dummyEnabled  = getConfig('dummy_enabled', true);
 $dummyFilename = getConfig('dummy_filename', 'dummy');
 $dummyImage = false;
 
 preg_match($validFilename, $srcImage)
-    or errorPage('Filename contains invalid characters.', 404);
+    or errorPage('Source filename contains invalid characters.', 404);
 
 if ($dummyEnabled && $srcImage === $dummyFilename) {
 
@@ -4105,24 +4249,47 @@ if ($dummyEnabled && $srcImage === $dummyFilename) {
 } elseif ($allowRemote && $img->isRemoteSource($srcImage)) {
 
     // If source is a remote file, ignore local file checks.
+    $remoteSource = true;
 
-} elseif ($imagePathConstraint) {
+} else {
 
-    // Check that the image is a file below the directory 'image_path'.
+    // Check if file exists on disk or try using src-alt
     $pathToImage = realpath($imagePath . $srcImage);
-    $imageDir    = realpath($imagePath);
 
-    is_file($pathToImage)
-        or errorPage(
-            'Source image is not a valid file, check the filename and that a
-            matching file exists on the filesystem.'
-        , 404);
+    if (!is_file($pathToImage) && !empty($srcAltImage)) {
+        // Try using the src-alt instead
+        $srcImage = $srcAltImage;
+        $pathToImage = realpath($imagePath . $srcImage);
+
+        preg_match($validFilename, $srcImage)
+            or errorPage('Source (alt) filename contains invalid characters.', 404);
+
+        if ($dummyEnabled && $srcImage === $dummyFilename) {
+            // Check if src-alt is the dummy image
+            $dummyImage = true;
+        }
+    }
+
+    if (!$dummyImage) {
+        is_file($pathToImage)
+            or errorPage(
+                'Source image is not a valid file, check the filename and that a
+                matching file exists on the filesystem.',
+                404
+            );
+    } 
+}
+
+if ($imagePathConstraint && !$dummyImage && !$remoteSource) {
+    // Check that the image is a file below the directory 'image_path'.
+    $imageDir = realpath($imagePath);
 
     substr_compare($imageDir, $pathToImage, 0, strlen($imageDir)) == 0
         or errorPage(
             'Security constraint: Source image is not below the directory "image_path"
-            as specified in the config file img_config.php.'
-        , 404);
+            as specified in the config file img_config.php.',
+            404
+        );
 }
 
 verbose("src = $srcImage");
@@ -4635,14 +4802,7 @@ verbose("alias = $alias");
 
 
 /**
- * Get the cachepath from config.
- */
-$cachePath = getConfig('cache_path', __DIR__ . '/../cache/');
-
-
-
-/**
- * Get the cachepath from config.
+ * Add cache control HTTP header.
  */
 $cacheControl = getConfig('cache_control', null);
 
@@ -4656,11 +4816,8 @@ if ($cacheControl) {
 /**
  * Prepare a dummy image and use it as source image.
  */
-$dummyDir = getConfig('dummy_dir', $cachePath. "/" . $dummyFilename);
-
 if ($dummyImage === true) {
-    is_writable($dummyDir)
-        or verbose("dummy dir not writable = $dummyDir");
+    $dummyDir = $cache->getPathToSubdir("dummy");
 
     $img->setSaveFolder($dummyDir)
         ->setSource($dummyFilename, $dummyDir)
@@ -4688,24 +4845,16 @@ if ($dummyImage === true) {
 /**
  * Prepare a sRGB version of the image and use it as source image.
  */
-$srgbDirName = "/srgb";
-$srgbDir     = realpath(getConfig('srgb_dir', $cachePath . $srgbDirName));
 $srgbDefault = getConfig('srgb_default', false);
 $srgbColorProfile = getConfig('srgb_colorprofile', __DIR__ . '/../icc/sRGB_IEC61966-2-1_black_scaled.icc');
 $srgb = getDefined('srgb', true, null);
 
 if ($srgb || $srgbDefault) {
 
-    if (!is_writable($srgbDir)) {
-        if (is_writable($cachePath)) {
-            mkdir($srgbDir);
-        }
-    }
-
     $filename = $img->convert2sRGBColorSpace(
         $srcImage,
         $imagePath,
-        $srgbDir,
+        $cache->getPathToSubdir("srgb"),
         $srgbColorProfile,
         $useCache
     );
@@ -4729,9 +4878,19 @@ if ($status) {
     $text .= "PHP version = " . PHP_VERSION . "\n";
     $text .= "Running on: " . $_SERVER['SERVER_SOFTWARE'] . "\n";
     $text .= "Allow remote images = $allowRemote\n";
-    $text .= "Cache writable = " . is_writable($cachePath) . "\n";
-    $text .= "Cache dummy writable = " . is_writable($dummyDir) . "\n";
-    $text .= "Cache srgb writable = " . is_writable($srgbDir) . "\n";
+
+    $res = $cache->getStatusOfSubdir("");
+    $text .= "Cache $res\n";
+
+    $res = $cache->getStatusOfSubdir("remote");
+    $text .= "Cache remote $res\n";
+
+    $res = $cache->getStatusOfSubdir("dummy");
+    $text .= "Cache dummy $res\n";
+
+    $res = $cache->getStatusOfSubdir("srgb");
+    $text .= "Cache srgb $res\n";
+
     $text .= "Alias path writable = " . is_writable($aliasPath) . "\n";
 
     $no = extension_loaded('exif') ? null : 'NOT';

webroot/imgp.php

@@ -430,7 +430,7 @@ class CRemoteImage
      */
     public function setCache($path)
     {
-        $this->saveFolder = $path;
+        $this->saveFolder = rtrim($path, "/") . "/";
         return $this;
     }
 
@@ -476,7 +476,12 @@ class CRemoteImage
      */
     public function setHeaderFields()
     {
-        $this->http->setHeader("User-Agent", "CImage/0.7.2 (PHP/". phpversion() . " cURL)");
+        $cimageVersion = "CImage";
+        if (defined("CIMAGE_USER_AGENT")) {
+            $cimageVersion = CIMAGE_USER_AGENT;
+        }
+        
+        $this->http->setHeader("User-Agent", "$cimageVersion (PHP/". phpversion() . " cURL)");
         $this->http->setHeader("Accept", "image/jpeg,image/png,image/gif");
 
         if ($this->useCache) {
@@ -880,7 +885,7 @@ class CAsciiArt
      */
     public function getLuminance($red, $green, $blue)
     {
-        switch($this->luminanceStrategy) {
+        switch ($this->luminanceStrategy) {
             case 1:
                 $luminance = ($red * 0.2126 + $green * 0.7152 + $blue * 0.0722) / 255;
                 break;
@@ -1263,20 +1268,27 @@ class CImage
 
 
     /**
-    * Calculate target dimension for image when using fill-to-fit resize strategy.
-    */
+     * Calculate target dimension for image when using fill-to-fit resize strategy.
+     */
     private $fillWidth;
     private $fillHeight;
 
 
 
     /**
-    * Allow remote file download, default is to disallow remote file download.
-    */
+     * Allow remote file download, default is to disallow remote file download.
+     */
     private $allowRemote = false;
 
 
 
+    /**
+     * Path to cache for remote download.
+     */
+    private $remoteCache;
+
+
+
     /**
      * Pattern to recognize a remote file.
      */
@@ -1431,13 +1443,15 @@ class CImage
      * Allow or disallow remote image download.
      *
      * @param boolean $allow   true or false to enable and disable.
+     * @param string  $cache   path to cache dir.
      * @param string  $pattern to use to detect if its a remote file.
      *
      * @return $this
      */
-    public function setRemoteDownload($allow, $pattern = null)
+    public function setRemoteDownload($allow, $cache, $pattern = null)
     {
         $this->allowRemote = $allow;
+        $this->remoteCache = $cache;
         $this->remotePattern = is_null($pattern) ? $this->remotePattern : $pattern;
 
         $this->log(
@@ -1569,21 +1583,12 @@ class CImage
         }
 
         $remote = new CRemoteImage();
-        $cache  = $this->saveFolder . "/remote/";
 
-        if (!is_dir($cache)) {
-            if (!is_writable($this->saveFolder)) {
-                throw new Exception("Can not create remote cache, cachefolder not writable.");
-            }
-            mkdir($cache);
-            $this->log("The remote cache does not exists, creating it.");
-        }
-
-        if (!is_writable($cache)) {
+        if (!is_writable($this->remoteCache)) {
             $this->log("The remote cache is not writable.");
         }
 
-        $remote->setCache($cache);
+        $remote->setCache($this->remoteCache);
         $remote->useCache($this->useCache);
         $src = $remote->download($src);
 
@@ -3694,6 +3699,115 @@ EOD;
 
 
 
+/**
+ * Deal with the cache directory and cached items.
+ *
+ */
+class CCache
+{
+    /**
+     * Path to the cache directory.
+     */
+    private $path;
+
+
+
+    /**
+     * Set the path to the cache dir which must exist.
+     *
+     * @param string path to the cache dir.
+     *
+     * @throws Exception when $path is not a directory.
+     *
+     * @return $this
+     */
+    public function setDir($path)
+    {
+        if (!is_dir($path)) {
+            throw new Exception("Cachedir is not a directory.");
+        }
+
+        $this->path = $path;
+
+        return $this;
+    }
+
+
+
+    /**
+     * Get the path to the cache subdir and try to create it if its not there.
+     *
+     * @param string $subdir name of subdir
+     * @param array  $create default is to try to create the subdir
+     *
+     * @return string | boolean as real path to the subdir or
+     *                          false if it does not exists
+     */
+    public function getPathToSubdir($subdir, $create = true)
+    {
+        $path = realpath($this->path . "/" . $subdir);
+
+        if (is_dir($path)) {
+            return $path;
+        }
+
+        if ($create && is_writable($this->path)) {
+            $path = $this->path . "/" . $subdir;
+
+            if (mkdir($path)) {
+                return realpath($path);
+            }
+        }
+
+        return false;
+    }
+
+
+
+    /**
+     * Get status of the cache subdir.
+     *
+     * @param string $subdir name of subdir
+     *
+     * @return string with status
+     */
+    public function getStatusOfSubdir($subdir)
+    {
+        $path = realpath($this->path . "/" . $subdir);
+
+        $exists = is_dir($path);
+        $res  = $exists ? "exists" : "does not exist";
+        
+        if ($exists) {
+            $res .= is_writable($path) ? ", writable" : ", not writable";
+        }
+
+        return $res;
+    }
+
+
+
+    /**
+     * Remove the cache subdir.
+     *
+     * @param string $subdir name of subdir
+     *
+     * @return null | boolean true if success else false, null if no operation
+     */
+    public function removeSubdir($subdir)
+    {
+        $path = realpath($this->path . "/" . $subdir);
+
+        if (is_dir($path)) {
+            return rmdir($path);
+        }
+
+        return null;
+    }
+}
+
+
+
 /**
  * Resize and crop images on the fly, store generated images in a cache.
  *
@@ -3703,7 +3817,10 @@ EOD;
  *
  */
 
-$version = "v0.7.8 (2015-12-06)";
+$version = "v0.7.10 (2016-04-01)";
+
+// For CRemoteImage
+define("CIMAGE_USER_AGENT", "CImage/$version");
 
 
 
@@ -3722,17 +3839,21 @@ function errorPage($msg, $type = 500)
     switch ($type) {
         case 403:
             $header = "403 Forbidden";
-        break;
+            break;
         case 404:
             $header = "404 Not Found";
-        break;
+            break;
         default:
             $header = "500 Internal Server Error";
     }
 
+    if ($mode == "strict") {
+        $header = "404 Not Found";
+    }
+
     header("HTTP/1.0 $header");
 
-    if ($mode == 'development') {
+    if ($mode == "development") {
         die("[img.php] $msg");
     }
 
@@ -3751,8 +3872,9 @@ set_exception_handler(function ($exception) {
         . $exception->getMessage()
         . "</p><pre>"
         . $exception->getTraceAsString()
-        . "</pre>"
-    , 500);
+        . "</pre>",
+        500
+    );
 });
 
 
@@ -3951,7 +4073,7 @@ $pwd         = get(array('password', 'pwd'), null);
 // Check if passwords match, if configured to use passwords
 $passwordMatch = null;
 if ($pwd) {
-    switch($pwdType) {
+    switch ($pwdType) {
         case 'md5':
             $passwordMatch = ($pwdConfig === md5($pwd));
             break;
@@ -4040,6 +4162,16 @@ $img->setVerbose($verbose || $verboseFile);
 
 
 
+/**
+ * Get the cachepath from config.
+ */
+$cachePath = getConfig('cache_path', __DIR__ . '/../cache/');
+$cache = new CCache();
+$cache->setDir($cachePath);
+
+
+
+
 /**
  * Allow or disallow remote download of images from other servers.
  * Passwords apply if used.
@@ -4048,8 +4180,10 @@ $img->setVerbose($verbose || $verboseFile);
 $allowRemote = getConfig('remote_allow', false);
 
 if ($allowRemote && $passwordMatch !== false) {
+    $cacheRemote = $cache->getPathToSubdir("remote");
+    
     $pattern = getConfig('remote_pattern', null);
-    $img->setRemoteDownload($allowRemote, $pattern);
+    $img->setRemoteDownload($allowRemote, $cacheRemote, $pattern);
 
     $whitelist = getConfig('remote_whitelist', null);
     $img->setRemoteHostWhitelist($whitelist);
@@ -4084,18 +4218,28 @@ if (isset($shortcut)
 $srcImage = urldecode(get('src'))
     or errorPage('Must set src-attribute.', 404);
 
+// Get settings for src-alt as backup image
+$srcAltImage = urldecode(get('src-alt', null));
+$srcAltConfig = getConfig('src_alt', null);
+if (empty($srcAltImage)) {
+    $srcAltImage = $srcAltConfig;
+}
+
 // Check for valid/invalid characters
 $imagePath           = getConfig('image_path', __DIR__ . '/img/');
 $imagePathConstraint = getConfig('image_path_constraint', true);
 $validFilename       = getConfig('valid_filename', '#^[a-z0-9A-Z-/_ \.:]+$#');
 
+// Source is remote
+$remoteSource = false;
+
 // Dummy image feature
 $dummyEnabled  = getConfig('dummy_enabled', true);
 $dummyFilename = getConfig('dummy_filename', 'dummy');
 $dummyImage = false;
 
 preg_match($validFilename, $srcImage)
-    or errorPage('Filename contains invalid characters.', 404);
+    or errorPage('Source filename contains invalid characters.', 404);
 
 if ($dummyEnabled && $srcImage === $dummyFilename) {
 
@@ -4105,24 +4249,47 @@ if ($dummyEnabled && $srcImage === $dummyFilename) {
 } elseif ($allowRemote && $img->isRemoteSource($srcImage)) {
 
     // If source is a remote file, ignore local file checks.
+    $remoteSource = true;
 
-} elseif ($imagePathConstraint) {
+} else {
 
-    // Check that the image is a file below the directory 'image_path'.
+    // Check if file exists on disk or try using src-alt
     $pathToImage = realpath($imagePath . $srcImage);
-    $imageDir    = realpath($imagePath);
 
-    is_file($pathToImage)
-        or errorPage(
-            'Source image is not a valid file, check the filename and that a
-            matching file exists on the filesystem.'
-        , 404);
+    if (!is_file($pathToImage) && !empty($srcAltImage)) {
+        // Try using the src-alt instead
+        $srcImage = $srcAltImage;
+        $pathToImage = realpath($imagePath . $srcImage);
+
+        preg_match($validFilename, $srcImage)
+            or errorPage('Source (alt) filename contains invalid characters.', 404);
+
+        if ($dummyEnabled && $srcImage === $dummyFilename) {
+            // Check if src-alt is the dummy image
+            $dummyImage = true;
+        }
+    }
+
+    if (!$dummyImage) {
+        is_file($pathToImage)
+            or errorPage(
+                'Source image is not a valid file, check the filename and that a
+                matching file exists on the filesystem.',
+                404
+            );
+    } 
+}
+
+if ($imagePathConstraint && !$dummyImage && !$remoteSource) {
+    // Check that the image is a file below the directory 'image_path'.
+    $imageDir = realpath($imagePath);
 
     substr_compare($imageDir, $pathToImage, 0, strlen($imageDir)) == 0
         or errorPage(
             'Security constraint: Source image is not below the directory "image_path"
-            as specified in the config file img_config.php.'
-        , 404);
+            as specified in the config file img_config.php.',
+            404
+        );
 }
 
 verbose("src = $srcImage");
@@ -4635,14 +4802,7 @@ verbose("alias = $alias");
 
 
 /**
- * Get the cachepath from config.
- */
-$cachePath = getConfig('cache_path', __DIR__ . '/../cache/');
-
-
-
-/**
- * Get the cachepath from config.
+ * Add cache control HTTP header.
  */
 $cacheControl = getConfig('cache_control', null);
 
@@ -4656,11 +4816,8 @@ if ($cacheControl) {
 /**
  * Prepare a dummy image and use it as source image.
  */
-$dummyDir = getConfig('dummy_dir', $cachePath. "/" . $dummyFilename);
-
 if ($dummyImage === true) {
-    is_writable($dummyDir)
-        or verbose("dummy dir not writable = $dummyDir");
+    $dummyDir = $cache->getPathToSubdir("dummy");
 
     $img->setSaveFolder($dummyDir)
         ->setSource($dummyFilename, $dummyDir)
@@ -4688,24 +4845,16 @@ if ($dummyImage === true) {
 /**
  * Prepare a sRGB version of the image and use it as source image.
  */
-$srgbDirName = "/srgb";
-$srgbDir     = realpath(getConfig('srgb_dir', $cachePath . $srgbDirName));
 $srgbDefault = getConfig('srgb_default', false);
 $srgbColorProfile = getConfig('srgb_colorprofile', __DIR__ . '/../icc/sRGB_IEC61966-2-1_black_scaled.icc');
 $srgb = getDefined('srgb', true, null);
 
 if ($srgb || $srgbDefault) {
 
-    if (!is_writable($srgbDir)) {
-        if (is_writable($cachePath)) {
-            mkdir($srgbDir);
-        }
-    }
-
     $filename = $img->convert2sRGBColorSpace(
         $srcImage,
         $imagePath,
-        $srgbDir,
+        $cache->getPathToSubdir("srgb"),
         $srgbColorProfile,
         $useCache
     );
@@ -4729,9 +4878,19 @@ if ($status) {
     $text .= "PHP version = " . PHP_VERSION . "\n";
     $text .= "Running on: " . $_SERVER['SERVER_SOFTWARE'] . "\n";
     $text .= "Allow remote images = $allowRemote\n";
-    $text .= "Cache writable = " . is_writable($cachePath) . "\n";
-    $text .= "Cache dummy writable = " . is_writable($dummyDir) . "\n";
-    $text .= "Cache srgb writable = " . is_writable($srgbDir) . "\n";
+
+    $res = $cache->getStatusOfSubdir("");
+    $text .= "Cache $res\n";
+
+    $res = $cache->getStatusOfSubdir("remote");
+    $text .= "Cache remote $res\n";
+
+    $res = $cache->getStatusOfSubdir("dummy");
+    $text .= "Cache dummy $res\n";
+
+    $res = $cache->getStatusOfSubdir("srgb");
+    $text .= "Cache srgb $res\n";
+
     $text .= "Alias path writable = " . is_writable($aliasPath) . "\n";
 
     $no = extension_loaded('exif') ? null : 'NOT';