Handles null comment cases

src/backend/distributed/deparser/deparse_database_stmts.c

@@ -323,10 +323,9 @@ DeparseDatabaseCommentStmt(Node *node)
 
 	char *databaseName = strVal(stmt->object);
 
+	char *comment = stmt->comment!=NULL?quote_literal_cstr(stmt->comment):"NULL";
 
-	appendStringInfo(&str, "COMMENT ON DATABASE %s IS %s;",
+	appendStringInfo(&str, "COMMENT ON DATABASE %s IS %s;",databaseName,comment);
-					 databaseName,
-					 quote_literal_cstr(stmt->comment));
 
 	return str.data;
 }

src/backend/distributed/deparser/deparse_role_stmts.c

@@ -543,11 +543,9 @@ DeparseRoleCommentStmt(Node *node)
 	initStringInfo(&str);
 
 	char *roleName = strVal(stmt->object);
+	char *comment = stmt->comment!=NULL?quote_literal_cstr(stmt->comment):"NULL";
 
-
+	appendStringInfo(&str, "COMMENT ON ROLE %s IS %s;",roleName,comment);
-	appendStringInfo(&str, "COMMENT ON ROLE %s IS %s;",
-					 roleName,
-					 quote_literal_cstr(stmt->comment));
 
 	return str.data;
 }

src/test/regress/expected/comment_on_database.out

@@ -5,10 +5,10 @@ create database test1;
 comment on DATABASE test1 is 'test-comment';
 SELECT result FROM run_command_on_all_nodes(
   $$
-  SELECT ds.description AS database_comment
+    SELECT ds.description AS database_comment
-FROM pg_database d
+    FROM pg_database d
-LEFT JOIN pg_shdescription ds ON d.oid = ds.objoid
+    LEFT JOIN pg_shdescription ds ON d.oid = ds.objoid
-WHERE d.datname = 'test1';
+    WHERE d.datname = 'test1';
   $$
 );
     result
@@ -21,10 +21,10 @@ WHERE d.datname = 'test1';
 comment on DATABASE test1 is 'comment-needs\!escape';
 SELECT result FROM run_command_on_all_nodes(
   $$
-  SELECT ds.description AS database_comment
+    SELECT ds.description AS database_comment
-FROM pg_database d
+    FROM pg_database d
-LEFT JOIN pg_shdescription ds ON d.oid = ds.objoid
+    LEFT JOIN pg_shdescription ds ON d.oid = ds.objoid
-WHERE d.datname = 'test1';
+    WHERE d.datname = 'test1';
   $$
 );
         result
@@ -32,6 +32,22 @@ WHERE d.datname = 'test1';
  comment-needs\!escape
  comment-needs\!escape
  comment-needs\!escape
+(3 rows)
+
+comment on DATABASE test1 is null;
+SELECT result FROM run_command_on_all_nodes(
+  $$
+    SELECT ds.description AS database_comment
+    FROM pg_database d
+    LEFT JOIN pg_shdescription ds ON d.oid = ds.objoid
+    WHERE d.datname = 'test1';
+  $$
+);
+ result
+---------------------------------------------------------------------
+
+
+
 (3 rows)
 
 drop DATABASE test1;

src/test/regress/expected/comment_on_role.out

@@ -31,6 +31,22 @@ SELECT result FROM run_command_on_all_nodes(
  comment-needs\!escape
  comment-needs\!escape
  comment-needs\!escape
+(3 rows)
+
+comment on role role1 is NULL;
+SELECT result FROM run_command_on_all_nodes(
+  $$
+    SELECT ds.description AS role_comment
+    FROM pg_roles r
+    LEFT JOIN pg_shdescription ds ON r.oid = ds.objoid
+    WHERE r.rolname = 'role1';
+  $$
+);
+ result
+---------------------------------------------------------------------
+
+
+
 (3 rows)
 
 drop role role1;

src/test/regress/sql/comment_on_database.sql

@@ -27,6 +27,17 @@ SELECT result FROM run_command_on_all_nodes(
   $$
 );
 
+comment on DATABASE test1 is null;
+
+SELECT result FROM run_command_on_all_nodes(
+  $$
+    SELECT ds.description AS database_comment
+    FROM pg_database d
+    LEFT JOIN pg_shdescription ds ON d.oid = ds.objoid
+    WHERE d.datname = 'test1';
+  $$
+);
+
 drop DATABASE test1;
 reset citus.enable_create_database_propagation;
 reset citus.grep_remote_commands;

src/test/regress/sql/comment_on_role.sql

@@ -26,6 +26,17 @@ SELECT result FROM run_command_on_all_nodes(
   $$
 );
 
+comment on role role1 is NULL;
+
+SELECT result FROM run_command_on_all_nodes(
+  $$
+    SELECT ds.description AS role_comment
+    FROM pg_roles r
+    LEFT JOIN pg_shdescription ds ON r.oid = ds.objoid
+    WHERE r.rolname = 'role1';
+  $$
+);
+
 drop role role1;
 reset citus.grep_remote_commands;
 reset citus.log_remote_commands;