On 2021-Mar-03, 'Alvaro Herrera' wrote:
> This should obviously not occur. I'm trying to figure out how to repair
> it and not break everything again ...
I think trying to set up the connection state so that the next query
appears in conn->last_query prior to PQgetResult being called again
leads to worse breakage. The simplest fix seems to make fe-protocol3.c
aware that in this case, the query is in conn->cmd_queue_head instead,
as in the attached patch.
--
Álvaro Herrera 39°49'30"S 73°17'W
diff --git a/src/interfaces/libpq/fe-protocol3.c b/src/interfaces/libpq/fe-protocol3.c
index 584922b340..b89f500902 100644
--- a/src/interfaces/libpq/fe-protocol3.c
+++ b/src/interfaces/libpq/fe-protocol3.c
@@ -962,9 +962,21 @@ pqGetErrorNotice3(PGconn *conn, bool isError)
* Save the active query text, if any, into res as well; but only if we
* might need it for an error cursor display, which is only true if there
* is a PG_DIAG_STATEMENT_POSITION field.
+ *
+ * Note that in pipeline mode, we have not yet advanced the query pointer
+ * to the next query, so we have to look at that.
*/
- if (have_position && conn->last_query && res)
- res->errQuery = pqResultStrdup(res, conn->last_query);
+ if (have_position && res)
+ {
+ if (conn->pipelineStatus != PQ_PIPELINE_OFF &&
+ conn->asyncStatus == PGASYNC_IDLE)
+ {
+ if (conn->cmd_queue_head)
+ res->errQuery = pqResultStrdup(res, conn->cmd_queue_head->query);
+ }
+ else if (conn->last_query)
+ res->errQuery = pqResultStrdup(res, conn->last_query);
+ }
/*
* Now build the "overall" error message for PQresultErrorMessage.
