>From 9e0ce5b3c4dae3bfcec04a516fc9c5f3102cbb0a Mon Sep 17 00:00:00 2001
From: Alvaro Herrera <alvherre@alvh.no-ip.org>
Date: Thu, 25 Sep 2014 15:44:44 -0300
Subject: [PATCH 04/42] deparse/core: event triggers support COMMENT

Have triggers on events ddl_command_start and ddl_command_end be invoked
on execution of COMMENT.
---
 doc/src/sgml/event-trigger.sgml      |  9 ++++++++-
 src/backend/commands/comment.c       |  5 ++++-
 src/backend/commands/event_trigger.c |  1 +
 src/backend/tcop/utility.c           | 21 +++++++++++++++++----
 src/include/commands/comment.h       |  2 +-
 5 files changed, 31 insertions(+), 7 deletions(-)

diff --git a/doc/src/sgml/event-trigger.sgml b/doc/src/sgml/event-trigger.sgml
index ed53587..58e0d9d 100644
--- a/doc/src/sgml/event-trigger.sgml
+++ b/doc/src/sgml/event-trigger.sgml
@@ -37,7 +37,7 @@
    <para>
      The <literal>ddl_command_start</> event occurs just before the
      execution of a <literal>CREATE</>, <literal>ALTER</>, <literal>DROP</>,
-     <literal>GRANT</> or <literal>REVOKE</>
+     <literal>COMMENT</>, <literal>GRANT</> or <literal>REVOKE</>
      command.  No check whether the affected object exists or doesn't exist is
      performed before the event trigger fires.
      As an exception, however, this event does not occur for
@@ -318,6 +318,13 @@
         <entry align="center"><literal>-</literal></entry>
        </row>
        <row>
+        <entry align="left"><literal>COMMENT</literal></entry>
+        <entry align="center"><literal>X</literal></entry>
+        <entry align="center"><literal>X</literal></entry>
+        <entry align="center"><literal>-</literal></entry>
+        <entry align="center"><literal>-</literal></entry>
+       </row>
+       <row>
         <entry align="left"><literal>CREATE CAST</literal></entry>
         <entry align="center"><literal>X</literal></entry>
         <entry align="center"><literal>X</literal></entry>
diff --git a/src/backend/commands/comment.c b/src/backend/commands/comment.c
index ed1e46e..e6929a6 100644
--- a/src/backend/commands/comment.c
+++ b/src/backend/commands/comment.c
@@ -37,7 +37,7 @@
  * pg_description for the object specified by the given SQL command.
  */
 Oid
-CommentObject(CommentStmt *stmt)
+CommentObject(CommentStmt *stmt, uint32 *objectSubId)
 {
 	ObjectAddress address;
 	Relation	relation;
@@ -126,6 +126,9 @@ CommentObject(CommentStmt *stmt)
 	if (relation != NULL)
 		relation_close(relation, NoLock);
 
+	if (objectSubId)
+		*objectSubId = address.objectSubId;
+
 	return address.objectId;
 }
 
diff --git a/src/backend/commands/event_trigger.c b/src/backend/commands/event_trigger.c
index 2eb6282..87b606c 100644
--- a/src/backend/commands/event_trigger.c
+++ b/src/backend/commands/event_trigger.c
@@ -267,6 +267,7 @@ check_ddl_tag(const char *tag)
 		pg_strcasecmp(tag, "REFRESH MATERIALIZED VIEW") == 0 ||
 		pg_strcasecmp(tag, "ALTER DEFAULT PRIVILEGES") == 0 ||
 		pg_strcasecmp(tag, "ALTER LARGE OBJECT") == 0 ||
+		pg_strcasecmp(tag, "COMMENT") == 0 ||
 		pg_strcasecmp(tag, "GRANT") == 0 ||
 		pg_strcasecmp(tag, "REVOKE") == 0 ||
 		pg_strcasecmp(tag, "DROP OWNED") == 0 ||
diff --git a/src/backend/tcop/utility.c b/src/backend/tcop/utility.c
index 9539f4f..ab13bfd 100644
--- a/src/backend/tcop/utility.c
+++ b/src/backend/tcop/utility.c
@@ -513,10 +513,6 @@ standard_ProcessUtility(Node *parsetree,
 			ExecuteTruncate((TruncateStmt *) parsetree);
 			break;
 
-		case T_CommentStmt:
-			CommentObject((CommentStmt *) parsetree);
-			break;
-
 		case T_SecLabelStmt:
 			ExecSecLabelStmt((SecLabelStmt *) parsetree);
 			break;
@@ -842,6 +838,19 @@ standard_ProcessUtility(Node *parsetree,
 			}
 			break;
 
+		case T_CommentStmt:
+			{
+				CommentStmt *stmt = (CommentStmt *) parsetree;
+
+				if (EventTriggerSupportsObjectType(stmt->objtype))
+					ProcessUtilitySlow(parsetree, queryString,
+									   context, params,
+									   dest, completionTag);
+				else
+					CommentObject((CommentStmt *) parsetree, NULL);
+				break;
+			}
+
 		default:
 			/* All other statement types have event trigger support */
 			ProcessUtilitySlow(parsetree, queryString,
@@ -1322,6 +1331,10 @@ ProcessUtilitySlow(Node *parsetree,
 				ExecAlterOwnerStmt((AlterOwnerStmt *) parsetree);
 				break;
 
+			case T_CommentStmt:
+				CommentObject((CommentStmt *) parsetree, NULL);
+				break;
+
 			case T_GrantStmt:
 				ExecuteGrantStmt((GrantStmt *) parsetree);
 				break;
diff --git a/src/include/commands/comment.h b/src/include/commands/comment.h
index 3d61b44..edc94d1 100644
--- a/src/include/commands/comment.h
+++ b/src/include/commands/comment.h
@@ -29,7 +29,7 @@
  *------------------------------------------------------------------
  */
 
-extern Oid	CommentObject(CommentStmt *stmt);
+extern Oid	CommentObject(CommentStmt *stmt, uint32 *objectSubId);
 
 extern void DeleteComments(Oid oid, Oid classoid, int32 subid);
 
-- 
2.1.4