fix(settings): do not emit errors if form fields are not present

Removing one of the forms from user settings results in errors being shown to the user.
This checks if form field was at all present before showing an error.

engine/lib/user_settings.php

@@ -9,8 +9,10 @@
 
 /**
  * Set a user's password
+ * Returns null if no change is required
+ * Returns true or false indicating success or failure if change was needed
  * 
- * @return bool
+ * @return bool|void
  * @since 1.8.0
  * @access private
  */
@@ -68,23 +70,30 @@ function _elgg_set_user_password() {
 		}
 	} else {
 		// no change
-		return null;
+		return;
 	}
 
 	return false;
 }
 
 /**
  * Set a user's display name
+ * Returns null if no change is required or input is not present in the form
+ * Returns true or false indicating success or failure if change was needed
  * 
- * @return bool
+ * @return bool|void
  * @since 1.8.0
  * @access private
  */
 function _elgg_set_user_name() {
-	$name = strip_tags(get_input('name'));
+	$name = get_input('name');
 	$user_guid = get_input('guid');
 
+	if (!isset($name)) {
+		return;
+	}
+
+	$name = strip_tags($name);
 	if ($user_guid) {
 		$user = get_user($user_guid);
 	} else {
@@ -107,7 +116,7 @@ function _elgg_set_user_name() {
 			}
 		} else {
 			// no change
-			return null;
+			return;
 		}
 	} else {
 		register_error(elgg_echo('user:name:fail'));
@@ -117,15 +126,21 @@ function _elgg_set_user_name() {
 
 /**
  * Set a user's language
+ * Returns null if no change is required or input is not present in the form
+ * Returns true or false indicating success or failure if change was needed
  * 
- * @return bool
+ * @return bool|void
  * @since 1.8.0
  * @access private
  */
 function _elgg_set_user_language() {
 	$language = get_input('language');
 	$user_guid = get_input('guid');
 
+	if (!isset($language)) {
+		return;
+	}
+
 	if ($user_guid) {
 		$user = get_user($user_guid);
 	} else {
@@ -143,7 +158,7 @@ function _elgg_set_user_language() {
 			}
 		} else {
 			// no change
-			return null;
+			return;
 		}
 	} else {
 		register_error(elgg_echo('user:language:fail'));
@@ -153,15 +168,21 @@ function _elgg_set_user_language() {
 
 /**
  * Set a user's email address
- *
- * @return bool
+ * Returns null if no change is required or input is not present in the form
+ * Returns true or false indicating success or failure if change was needed
+ * 
+ * @return bool|void
  * @since 1.8.0
  * @access private
  */
 function _elgg_set_user_email() {
 	$email = get_input('email');
 	$user_guid = get_input('guid');
 
+	if (!isset($email)) {
+		return;
+	}
+
 	if ($user_guid) {
 		$user = get_user($user_guid);
 	} else {
@@ -191,7 +212,7 @@ function _elgg_set_user_email() {
 			}
 		} else {
 			// no change
-			return null;
+			return;
 		}
 	} else {
 		register_error(elgg_echo('email:save:fail'));
@@ -201,15 +222,17 @@ function _elgg_set_user_email() {
 
 /**
  * Set a user's default access level
+ * Returns null if no change is required or input is not present in the form
+ * Returns true or false indicating success or failure if change was needed
  *
- * @return bool
+ * @return bool|void
  * @since 1.8.0
  * @access private
  */
 function _elgg_set_user_default_access() {
 
 	if (!elgg_get_config('allow_user_default_access')) {
-		return false;
+		return;
 	}
 
 	$default_access = get_input('default_access');
@@ -232,7 +255,7 @@ function _elgg_set_user_default_access() {
 			}
 		} else {
 			// no change
-			return null;
+			return;
 		}
 	} else {
 		register_error(elgg_echo('user:default_access:failure'));