diff --git a/core/polyfills.php b/core/polyfills.php
index 4d87b519..680879f4 100644
--- a/core/polyfills.php
+++ b/core/polyfills.php
@@ -752,3 +752,53 @@ function validate_input(array $inputs): array
 
     return $outputs;
 }
+
+/**
+ * Translates all possible directory separators to the appropriate one for the current system,
+ * and removes any duplicate separators.
+ */
+function sanitize_path(string $path): string
+{
+    return preg_replace('|[\\\\/]+|S',DIRECTORY_SEPARATOR,$path);
+}
+
+/**
+ * Combines all path segments specified, ensuring no duplicate separators occur,
+ * as well as converting all possible separators to the one appropriate for the current system.
+ */
+function join_path(string ...$paths): string
+{
+    $output = "";
+    foreach ($paths as $path) {
+        if(empty($path)) {
+            continue;
+        }
+        $path = sanitize_path($path);
+        if(empty($output)) {
+            $output = $path;
+        } else {
+            $output = rtrim($output, DIRECTORY_SEPARATOR);
+            $path = ltrim($path, DIRECTORY_SEPARATOR);
+            $output .= DIRECTORY_SEPARATOR . $path;
+        }
+    }
+    return $output;
+}
+
+/**
+ * Perform callback on each item returned by an iterator.
+ */
+function iterator_map(callable $callback, iterator $iter): Generator
+{
+    foreach($iter as $i) {
+        yield call_user_func($callback,$i);
+    }
+}
+
+/**
+ * Perform callback on each item returned by an iterator and combine the result into an array.
+ */
+function iterator_map_to_array(callable $callback, iterator $iter): array
+{
+    return iterator_to_array(iterator_map($callback, $iter));
+}
\ No newline at end of file
diff --git a/core/tests/polyfills.test.php b/core/tests/polyfills.test.php
index 7aadec3d..68e0d10a 100644
--- a/core/tests/polyfills.test.php
+++ b/core/tests/polyfills.test.php
@@ -45,4 +45,77 @@ class PolyfillsTest extends \PHPUnit\Framework\TestCase
         $this->assertEquals(parse_shorthand_int("43.4KB"), 44441);
         $this->assertEquals(parse_shorthand_int("1231231231"), 1231231231);
     }
+
+    public function test_sanitize_path()
+    {
+
+        $this->assertEquals(
+            "one",
+            sanitize_path("one")
+        );
+
+        $this->assertEquals(
+            "one".DIRECTORY_SEPARATOR."two",
+            sanitize_path("one\\two")
+        );
+
+        $this->assertEquals(
+            "one".DIRECTORY_SEPARATOR."two",
+            sanitize_path("one/two")
+        );
+
+        $this->assertEquals(
+            "one".DIRECTORY_SEPARATOR."two",
+            sanitize_path("one\\\\two")
+        );
+
+        $this->assertEquals(
+            "one".DIRECTORY_SEPARATOR."two",
+            sanitize_path("one//two")
+        );
+
+        $this->assertEquals(
+            "one".DIRECTORY_SEPARATOR."two",
+            sanitize_path("one\\\\\\two")
+        );
+
+        $this->assertEquals(
+            "one".DIRECTORY_SEPARATOR."two",
+            sanitize_path("one///two")
+        );
+
+        $this->assertEquals(
+            DIRECTORY_SEPARATOR."one".DIRECTORY_SEPARATOR."two".DIRECTORY_SEPARATOR,
+            sanitize_path("\\/one/\\/\\/two\\/")
+        );
+
+    }
+
+    public function test_join_path()
+    {
+        $this->assertEquals(
+            "one",
+            join_path("one")
+        );
+
+        $this->assertEquals(
+            "one".DIRECTORY_SEPARATOR."two",
+            join_path("one","two")
+        );
+
+        $this->assertEquals(
+            "one".DIRECTORY_SEPARATOR."two".DIRECTORY_SEPARATOR."three",
+            join_path("one","two","three")
+        );
+
+        $this->assertEquals(
+            "one".DIRECTORY_SEPARATOR."two".DIRECTORY_SEPARATOR."three",
+            join_path("one/two","three")
+        );
+
+        $this->assertEquals(
+            DIRECTORY_SEPARATOR."one".DIRECTORY_SEPARATOR."two".DIRECTORY_SEPARATOR."three".DIRECTORY_SEPARATOR,
+            join_path("\\/////\\\\one/\///"."\\//two\/\\//\\//","//\/\\\/three/\\/\/")
+        );
+    }
 }
diff --git a/core/tests/util.test.php b/core/tests/util.test.php
index 9087dde5..3b3381f7 100644
--- a/core/tests/util.test.php
+++ b/core/tests/util.test.php
@@ -3,78 +3,6 @@ require_once "core/util.php";
 
 class UtilTest extends \PHPUnit\Framework\TestCase
 {
-    public function test_sanitize_path()
-    {
-
-        $this->assertEquals(
-            "one",
-            sanitize_path("one")
-        );
-
-        $this->assertEquals(
-            "one".DIRECTORY_SEPARATOR."two",
-            sanitize_path("one\\two")
-        );
-
-        $this->assertEquals(
-            "one".DIRECTORY_SEPARATOR."two",
-            sanitize_path("one/two")
-        );
-
-        $this->assertEquals(
-            "one".DIRECTORY_SEPARATOR."two",
-            sanitize_path("one\\\\two")
-        );
-
-        $this->assertEquals(
-            "one".DIRECTORY_SEPARATOR."two",
-            sanitize_path("one//two")
-        );
-
-        $this->assertEquals(
-            "one".DIRECTORY_SEPARATOR."two",
-            sanitize_path("one\\\\\\two")
-        );
-
-        $this->assertEquals(
-            "one".DIRECTORY_SEPARATOR."two",
-            sanitize_path("one///two")
-        );
-
-        $this->assertEquals(
-            DIRECTORY_SEPARATOR."one".DIRECTORY_SEPARATOR."two".DIRECTORY_SEPARATOR,
-            sanitize_path("\\/one/\\/\\/two\\/")
-        );
-
-    }
-
-    public function test_join_path()
-    {
-        $this->assertEquals(
-            "one",
-            join_path("one")
-        );
-
-        $this->assertEquals(
-            "one".DIRECTORY_SEPARATOR."two",
-            join_path("one","two")
-        );
-
-        $this->assertEquals(
-            "one".DIRECTORY_SEPARATOR."two".DIRECTORY_SEPARATOR."three",
-            join_path("one","two","three")
-        );
-
-        $this->assertEquals(
-            "one".DIRECTORY_SEPARATOR."two".DIRECTORY_SEPARATOR."three",
-            join_path("one/two","three")
-        );
-
-        $this->assertEquals(
-            DIRECTORY_SEPARATOR."one".DIRECTORY_SEPARATOR."two".DIRECTORY_SEPARATOR."three".DIRECTORY_SEPARATOR,
-            join_path("\\/////\\\\one/\///"."\\//two\/\\//\\//","//\/\\\/three/\\/\/")
-        );
-    }
 
     public function test_warehouse_path()
     {
diff --git a/core/util.php b/core/util.php
index ee7b39fc..43f62dd1 100644
--- a/core/util.php
+++ b/core/util.php
@@ -338,37 +338,6 @@ function path_to_tags(string $path): string
     return implode(" ", $tags);
 }
 
-/**
- * Translates all possible directory separators to the appropriate one for the current system,
- * and removes any duplicate separators.
- */
-function sanitize_path(string $path): string
-{
-    return preg_replace('|[\\\\/]+|S',DIRECTORY_SEPARATOR,$path);
-}
-
-/**
- * Combines all path segments specified, ensuring no duplicate separators occur,
- * as well as converting all possible separators to the one appropriate for the current system.
- */
-function join_path(string ...$paths): string
-{
-    $output = "";
-    foreach ($paths as $path) {
-        if(empty($path)) {
-            continue;
-        }
-        $path = sanitize_path($path);
-        if(empty($output)) {
-            $output = $path;
-        } else {
-            $output = rtrim($output, DIRECTORY_SEPARATOR);
-            $path = ltrim($path, DIRECTORY_SEPARATOR);
-            $output .= DIRECTORY_SEPARATOR . $path;
-        }
-    }
-    return $output;
-}
 
 function join_url(string $base, string ...$paths)
 {
diff --git a/ext/pools/main.php b/ext/pools/main.php
index 3a8b5a2b..37a1cc01 100644
--- a/ext/pools/main.php
+++ b/ext/pools/main.php
@@ -432,26 +432,18 @@ class Pools extends Extension
                 $pool = $this->get_pool($pool_id);
 
                 if ($this->have_permission($user, $pool)) {
-                    $ids = [];
-                    foreach($event->items as $item) {
-                        $ids[] = $item->id;
-                    }
-                    send_event(new PoolAddPostsEvent($pool_id, $ids));
+                    send_event(
+                        new PoolAddPostsEvent($pool_id,iterator_map_to_array("image_to_id", $event->items)));
                 }
                 break;
             case "bulk_pool_add_new":
                 if (!isset($_POST['bulk_pool_new'])) {
                     return;
                 }
-                $ids = [];
-                foreach($event->items as $item) {
-                    $ids[] = $item->id;
-                }
-
                 $new_pool_title = $_POST['bulk_pool_new'];
                 $pce = new PoolCreationEvent($new_pool_title);
                 send_event($pce);
-                send_event(new PoolAddPostsEvent($pce->new_id, $ids));
+                send_event(new PoolAddPostsEvent($pce->new_id, iterator_map_to_array("image_to_id", $event->items)));
                 break;
         }
     }