--- contrib/image_attach/image_attach.module	2009-11-25 08:09:09.000000000 +0000
+++ contrib/image_attach/image_attach.module	2009-11-25 18:20:15.000000000 +0000
@@ -147,6 +147,14 @@ function image_attach_form_alter(&$form,
       '#options' => array(0 => t('Disabled'), 1 => t('Enabled')),
       '#description' => t('Should this node allows users to upload an image?'),
     );
+    $number_of_images = array(0 => t('Unlimited'), 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 20, 30, 40, 50, 75, 100, 150, 200, 300, 400, 500);
+    $form['image_attach']['image_attach_maximum'] = array(
+      '#type' => 'select',
+      '#title' => t('Maximum number of images'),
+      '#default_value' => variable_get('image_attach_maximum_'. $form['#node_type']->type, 0),
+      '#options' => $number_of_images,
+      '#description' => t('Select the maximum number of images that may be attached to this node type.'),
+    );
     $form['image_attach']['image_attach_size_teaser'] = array(
       '#type' => 'select',
       '#title' => t('Teaser image size'),
@@ -294,29 +302,54 @@ function image_attach_image_add_submit(&
 }
 
 /**
+ * Image attach validation handler for node edit form.
+ *
+ * Check that the number of images has not exceeded the maximum.
  * Capture node form submission and immediately create an image if one has been
  * uploaded.
  * Note that the new image nodes are created even on preview. Taking several
  * attempts may create trash.
  */
 function image_attach_validate(&$form, &$form_state) {
-  $validators = array(
-    'file_validate_is_image' => array(),
-  );
-  if ($file = file_save_upload('image', $validators)) {
-    $image_title = $_POST['image_title'] ? $_POST['image_title'] : basename($file->filepath);
-    // Initialize an image properly.
-    $image = image_create_node_from($file->filepath, $image_title, '');
-    if ($image && !form_get_errors()) {
-      drupal_set_message(t("Created new image to attach to this node. !image_link", array('!image_link' => l($image_title, 'node/'. $image->nid) )));
-      // Append image nid to array of images.
-      $form_state['values']['iids'][$image->nid] = $image->nid;
+  // Validate the number of attached images. Filter out the 'None' with array_filter.
+  if ($maximum = variable_get('image_attach_maximum_'. $form['#node']->type, 0)) {
+    $uploading_new_image = ($form_state['clicked_button']['#value'] == t('Attach'));
+    $num_images = count(array_filter($form_state['values']['iids']));
+    if ($num_images >= $maximum && $uploading_new_image) {
+      // This error will be set when attempting to upload a new image. The number already selected may be equal to the
+      // maximum, in which case the error is just to alert the user that their upload has not been performed, and allow
+      // them to unselect an image and proceed to upload the new one.
+      form_set_error('iids', format_plural($num_images,
+        'You have selected @num_images image and the maximum for a @type entry is @maximum. The new image has not been uploaded.',
+        'You have selected @num_images images and the maximum for a @type entry is @maximum. The new image has not been uploaded.',
+        array('@num_images' => $num_images, '@maximum' => $maximum, '@type' =>  $form['#node']->type)));
+    }
+    elseif ($num_images > $maximum) {
+      form_set_error('iids', t('You have selected @num_images images but the maximum for a @type entry is @maximum.',
+        array('@num_images' => $num_images, '@maximum' => $maximum, '@type' =>  $form['#node']->type)));
     }
   }
-  else {
-    // Only raise error if user clicked specific Attach button.
-    if ($form_state['clicked_button']['#value'] == 'Attach') {
-      form_set_error('image_attach', t('Invalid or missing image file for upload and attach.'));
+
+  // Validate and save the uploaded image, providing that there are no errors set.
+  if (!count(form_get_errors())) {
+    $validators = array(
+      'file_validate_is_image' => array(),
+    );
+    if ($file = file_save_upload('image', $validators)) {
+      $image_title = $_POST['image_title'] ? $_POST['image_title'] : basename($file->filepath);
+      // Initialize an image properly.
+      $image = image_create_node_from($file->filepath, $image_title, '');
+      if ($image && !form_get_errors()) {
+        drupal_set_message(t("Created new image to attach to this node. !image_link", array('!image_link' => l($image_title, 'node/'. $image->nid) )));
+        // Append image nid to array of images.
+        $form_state['values']['iids'][$image->nid] = $image->nid;
+      }
+    }
+    else {
+      // Only raise error if user clicked specific Attach button.
+      if ($form_state['clicked_button']['#value'] == t('Attach')) {
+        form_set_error('image_attach', t('Invalid or missing image file for upload and attach.'));
+      }
     }
   }
 }