Allow emoji in contribution names

includes/objects/contribution.php

@@ -1091,6 +1091,13 @@ public function set_demo_url($branch, $url)
 	 */
 	public function submit()
 	{
+		// Emojis and other four byte characters are not allowed by MySQL in the
+		// utf8 column the name is stored in, so replace them with their numeric
+		// character reference, as core does for report text. Doing it here keeps
+		// the encoded form out of everything that reads the name, including the
+		// release topic subject and the generated slug.
+		$this->contrib_name = utf8_encode_ucr($this->contrib_name);
+
 		if (!$this->contrib_id)
 		{
 			// Make sure the author exists, if not we create one (do this before returning if not approved...else we need to duplicate this code in a bunch of places)

url/url.php

@@ -192,6 +192,13 @@ public function remove_nth_param($nth)
 	 */
 	public static function generate_slug($string)
 	{
+		// Neither a character reference nor a character outside the basic
+		// multilingual plane belongs in a slug: the columns slugs are stored in
+		// are utf8, which cannot hold the latter, and the digits of the former
+		// would end up in the URL.
+		$string = preg_replace('/&#[0-9]+;/', '', $string);
+		$string = preg_replace('/[\x{10000}-\x{10FFFF}]/u', '', $string);
+
 		$string = self::url_replace($string, false);
 
 		// Replace any number of spaces with a single underscore