From: Tom Lane <tgl@sss.pgh.pa.us>
Date: Fri, 24 Nov 2006 23:07:01 +0000 (+0000)
Subject: Fix psql's \copy command to ensure that it cycles libpq back to the idle state
X-Git-Url: http://git.postgresql.org/gitweb/static/gitweb.js?a=commitdiff_plain;h=6f58ce20a3c03babe10a35e711e191170d49a461;p=users%2Fbernd%2Fpostgres.git

Fix psql's \copy command to ensure that it cycles libpq back to the idle state
(in particular, causing the ReadyForQuery message to be eaten) before
returning from do_copy.  The only known consequence of failing to do so is
that get_prompt might show a wrong result for the %x transaction status
escape, as reported by Bernd Helmle; but it's possible there are other issues.

Back-patch as far as 7.4, the oldest version supporting %x.
---

diff --git a/src/bin/psql/copy.c b/src/bin/psql/copy.c
index cb12674bdc..324b53892c 100644
--- a/src/bin/psql/copy.c
+++ b/src/bin/psql/copy.c
@@ -568,6 +568,18 @@ do_copy(const char *args)
 
 	PQclear(result);
 
+	/*
+	 * Make sure we have pumped libpq dry of results; else it may still be
+	 * in ASYNC_BUSY state, leading to false readings in, eg, get_prompt().
+	 */
+	while ((result = PQgetResult(pset.db)) != NULL)
+	{
+		success = false;
+		psql_error("\\copy: unexpected response (%d)\n",
+				   PQresultStatus(result));
+		PQclear(result);
+	}
+
 	if (options->file != NULL)
 	{
 		if (fclose(copystream) != 0)