Followup r73348, r70608: move 'infinity' stuff to DB classes

includes/Block.php

@@ -849,25 +849,12 @@ class Block {
 
 	/**
 	 * Get a value to insert into expiry field of the database when infinite expiry
-	 * is desired. In principle this could be DBMS-dependant, but currently all
-	 * supported DBMS's support the string "infinity", so we just use that.
+	 * is desired
 	 *
 	 * @return String
 	 */
 	public static function infinity() {
-		# This is a special keyword for timestamps in PostgreSQL, and
-		# works with CHAR(14) as well because "i" sorts after all numbers.
-
-		# BEGIN DatabaseMssql hack
-		# Since MSSQL doesn't recognize the infinity keyword, set date manually.
-		# TO-DO: Refactor for better DB portability and remove magic date
-		$dbr = wfGetDB( DB_SLAVE );
-		if ( $dbr->getType() == 'mssql' ) {
-			return '3000-01-31 00:00:00.000';
-		}
-		# End DatabaseMssql hack
-
-		return 'infinity';
+		return wfGetDB( DB_SLAVE )->getInfinity();
 	}
 
 	/**

includes/db/Database.php

@@ -2663,6 +2663,17 @@ abstract class DatabaseBase implements DatabaseType {
 		return 'SearchEngineDummy';
 	}
 
+	/**
+	 * Find out when 'infinity' is. Most DBMSes support this. This is a special
+	 * keyword for timestamps in PostgreSQL, and works with CHAR(14) as well
+	 * because "i" sorts after all numbers.
+	 *
+	 * @return String
+	 */
+	public function getInfinity() {
+		return 'infinity';
+	}
+
 	/**
 	 * Allow or deny "big selects" for this session only. This is done by setting
 	 * the sql_big_selects session variable.

includes/db/DatabaseMssql.php

@@ -1040,6 +1040,14 @@ class DatabaseMssql extends DatabaseBase {
 		return "SearchMssql";
 	}
 
+	/**
+	 * Since MSSQL doesn't recognize the infinity keyword, set date manually.
+	 * @todo Remove magic date
+	 */
+	public function getInfinity() {
+		return '3000-01-31 00:00:00.000';
+	}
+
 } // end DatabaseMssql class
 
 /**