Allow 'ELSEIF' as an alternative to 'ELSIF' in PL/PgSQL. There have been

several reports of users being confused when they attempt to use ELSEIF
and run into trouble due to PL/PgSQL's lax parser. The parser will be
improved for 8.1, but we can fix most of the problem by allowing ELSEIF
for now.

doc/src/sgml/plpgsql.sgml

 <!--
-$PostgreSQL: pgsql/doc/src/sgml/plpgsql.sgml,v 1.51 2004/12/13 18:05:08 petere Exp $
+$PostgreSQL: pgsql/doc/src/sgml/plpgsql.sgml,v 1.52 2004/12/17 03:51:34 neilc Exp $
 -->
 
 <chapter id="plpgsql"> 
@@ -1475,7 +1475,7 @@ SELECT * FROM some_func();
 
     <para>
      <literal>IF</> statements let you execute commands based on
-     certain conditions.  <application>PL/pgSQL</> has four forms of
+     certain conditions.  <application>PL/pgSQL</> has five forms of
      <literal>IF</>:
     <itemizedlist>
      <listitem>
@@ -1490,6 +1490,9 @@ SELECT * FROM some_func();
      <listitem>
       <para><literal>IF ... THEN ... ELSIF ... THEN ... ELSE</></>
      </listitem>
+     <listitem>
+      <para><literal>IF ... THEN ... ELSEIF ... THEN ... ELSE</></>
+     </listitem>
     </itemizedlist>
     </para>
 
@@ -1633,6 +1636,13 @@ END IF;
 </programlisting>
        </para>
      </sect3>
+
+     <sect3>
+      <title><literal>IF-THEN-ELSEIF-ELSE</></title>
+
+      <para>
+       <literal>ELSEIF</> is an alias for <literal>ELSIF</>.
+     </para>
    </sect2>
 
    <sect2 id="plpgsql-control-structures-loops">

src/pl/plpgsql/src/scan.l

@@ -4,7 +4,7 @@
  *			  procedural language
  *
  * IDENTIFICATION
- *    $PostgreSQL: pgsql/src/pl/plpgsql/src/scan.l,v 1.37 2004/09/13 01:45:32 neilc Exp $
+ *    $PostgreSQL: pgsql/src/pl/plpgsql/src/scan.l,v 1.38 2004/12/17 03:51:36 neilc Exp $
  *
  *    This software is copyrighted by Jan Wieck - Hamburg.
  *
@@ -144,6 +144,7 @@ declare			{ return K_DECLARE;			}
 default			{ return K_DEFAULT;			}
 diagnostics		{ return K_DIAGNOSTICS;		}
 else			{ return K_ELSE;			}
+elseif          { return K_ELSIF;           }
 elsif           { return K_ELSIF;           }
 end				{ return K_END;				}
 exception		{ return K_EXCEPTION;		}