select combine_table() error for official example

[namo-ratna-trayaya]

CREATE FOREIGN TABLE wiki_stream (
hour timestamp,
project text,
title text,
view_count bigint,
size bigint)
SERVER pipelinedb;

CREATE VIEW wiki_stats WITH (action=materialize) AS
SELECT hour, project,
count(*) AS total_pages,
sum(view_count) AS total_views,
min(view_count) AS min_views,
max(view_count) AS max_views,
avg(view_count) AS avg_views,
percentile_cont(0.99) WITHIN GROUP (ORDER BY view_count) AS p99_views,
sum(size) AS total_bytes_served
FROM wiki_stream
GROUP BY hour, project;

insert into wiki_stream values('now()','a','a',1,1);

select * into wiki_stats_tmp from wiki_stats_mrel ;

select pipelinedb.combine_table('wiki_stats', 'wiki_stats_tmp');

got error like this:

postgres=# select pipelinedb.combine_table('wiki_stats', 'wiki_stats_tmp');
ERROR: invalid string enlargement request size: -4

[JiaxingSong]

In analyzer.c , rewrite_nodes(), make then following change:

FROM:
if (IsContQueryProcess())
return;

TO:
if (IsContQueryProcess() || PipelineContextIsCombineTable())
return;

add the combine table case to the scenarios like combiner or worker processes, can avoid this bug,