TablePager: fix param documentation for formatValue()

Can receive null value if the field isn't in the database result.

Change-Id: Id995a384dc58f5d8216a7309490b98558004d071

includes/pager/TablePager.php

@@ -465,7 +465,8 @@ abstract class TablePager extends IndexPager {
 	 * need more context.
 	 *
 	 * @param string $name The database field name
-	 * @param string $value The value retrieved from the database
+	 * @param string|null $value The value retrieved from the database, or null if
+	 *   the row doesn't contain this field
 	 */
 	abstract public function formatValue( $name, $value );
 

includes/specials/pagers/AllMessagesTablePager.php

@@ -273,7 +273,7 @@ class AllMessagesTablePager extends TablePager {
 
 	/**
 	 * @param string $field
-	 * @param string $value
+	 * @param string|null $value
 	 * @return string HTML
 	 */
 	public function formatValue( $field, $value ) {

includes/specials/pagers/BlockListPager.php

@@ -121,7 +121,7 @@ class BlockListPager extends TablePager {
 
 	/**
 	 * @param string $name
-	 * @param string $value
+	 * @param string|null $value
 	 * @return string
 	 * @suppress PhanTypeArraySuspicious
 	 */

includes/specials/pagers/ImageListPager.php

@@ -454,7 +454,7 @@ class ImageListPager extends TablePager {
 
 	/**
 	 * @param string $field
-	 * @param string $value
+	 * @param string|null $value
 	 * @return Message|string|int The return type depends on the value of $field:
 	 *   - thumb: string
 	 *   - img_timestamp: string

includes/specials/pagers/ProtectedPagesPager.php

@@ -137,7 +137,7 @@ class ProtectedPagesPager extends TablePager {
 
 	/**
 	 * @param string $field
-	 * @param string $value
+	 * @param string|null $value
 	 * @return string HTML
 	 * @throws MWException
 	 */