From e5403b226012013e92e742d066da05372ea235c4 Mon Sep 17 00:00:00 2001
From: Hiroshi Inoue <inoue@tpf.co.jp>
Date: Tue, 24 Oct 2006 11:24:35 +0000
Subject: [PATCH] Avoid backend crash caused by Execute Requests for committed
 holdable cursors.

---
 qresult.c   | 27 +++++++++++++++++----------
 results.c   |  8 +++++++-
 statement.c | 18 ++++++++++++++----
 3 files changed, 38 insertions(+), 15 deletions(-)

diff --git a/qresult.c b/qresult.c
index d11b8e7..680bc60 100644
--- a/qresult.c
+++ b/qresult.c
@@ -806,6 +806,7 @@ QR_next_tuple(QResultClass *self, StatementClass *stmt)
 	ConnInfo   *ci = NULL;
 	BOOL		msg_truncated, rcvend, internally_invoked = FALSE;
 	BOOL		reached_eof_now = FALSE, curr_eof; /* detecting EOF is pretty important */
+	BOOL		ExecuteRequest = FALSE;
 	Int4		response_length;
 
 inolog("Oh %p->fetch_number=%d\n", self, self->fetch_number);
@@ -1060,8 +1061,11 @@ inolog("clear obsolete %d tuples\n", num_backend_rows);
 
 		if (enlargeKeyCache(self, self->cache_size - num_backend_rows, "Out of memory while reading tuples") < 0)
 			return FALSE;
-		if (PROTOCOL_74(ci))
+		if (PROTOCOL_74(ci)
+		    && !QR_is_permanent(self) /* Execute seems an invalid operation after COMMIT */ 
+			)
 		{
+			ExecuteRequest = TRUE;
 			if (!SendExecuteRequest(stmt, QR_get_cursor(self),
 				fetch_size))
 				return FALSE;
@@ -1119,6 +1123,8 @@ inolog("reached_eof_now=%d\n", reached_eof_now);
 	for (rcvend = FALSE; !rcvend;)
 	{
 		id = SOCK_get_id(sock);
+		if (0 != SOCK_get_errcode(sock))
+			break;
 		response_length = SOCK_get_response_length(sock);
 inolog("id='%c' response_length=%d\n", id, response_length);
 		switch (id)
@@ -1184,7 +1190,7 @@ inolog("id='%c' response_length=%d\n", id, response_length);
 					QR_set_no_fetching_tuples(self);
 					if (internally_invoked)
 					{
-						if (PROTOCOL_74(ci)) /* Execute completed without accepting Portal Suspend */
+						if (ExecuteRequest) /* Execute completed without accepting Portal Suspend */
 							reached_eof_now = TRUE;
 						else if (cur_fetch < fetch_size)
 							reached_eof_now = TRUE;
@@ -1248,16 +1254,17 @@ inolog("id='%c' response_length=%d\n", id, response_length);
 				rcvend = TRUE;
 		}
 		if (0 != SOCK_get_errcode(sock))
-		{
-			if (QR_command_maybe_successful(self))
-			{
-				QR_set_message(self, "Communication error while getting a tuple");
-				QR_set_rstatus(self, PORES_FATAL_ERROR);
-			}
-			CC_on_abort(conn, CONN_DEAD);
-			ret = FALSE;
 			break;
+	}
+	if (0 != SOCK_get_errcode(sock))
+	{
+		if (QR_command_maybe_successful(self))
+		{
+			QR_set_message(self, "Communication error while getting a tuple");
+			QR_set_rstatus(self, PORES_FATAL_ERROR);
 		}
+		CC_on_abort(conn, CONN_DEAD);
+		ret = FALSE;
 	}
 	if (!ret)
 		return ret;
diff --git a/results.c b/results.c
index ab92f6f..3dbf09c 100644
--- a/results.c
+++ b/results.c
@@ -1746,6 +1746,8 @@ inolog("num_tuples=%d\n", num_tuples);
 	currp = -1;
 	stmt->bind_row = 0;		/* set the binding location */
 	result = SC_fetch(stmt);
+	if (SQL_ERROR == result)
+		goto cleanup;
 	if (SQL_NO_DATA_FOUND != result && res->keyset)
 	{
 		currp = GIdx2KResIdx(SC_get_rowset_start(stmt), stmt, res);
@@ -1758,7 +1760,7 @@ inolog("currp=%d\n", currp);
 			goto cleanup;
 		}
 	}
-	for (i = 0, fc_io = 0; SQL_NO_DATA_FOUND != result; currp++)
+	for (i = 0, fc_io = 0; SQL_NO_DATA_FOUND != result && SQL_ERROR != result; currp++)
 	{
 		fc_io++;
 		currp_is_valid = FALSE;
@@ -1781,6 +1783,8 @@ inolog("ExtFetch result=%d\n", result);
 inolog("just skipping deleted row %d\n", currp);
 			QR_set_rowset_size(res, (Int4) (rowsetSize - i + fc_io));
 			result = SC_fetch(stmt);
+			if (SQL_ERROR == result)
+				break;
 			continue;
 		}
 
@@ -1819,6 +1823,8 @@ inolog("just skipping deleted row %d\n", currp);
 		stmt->bind_row = (SQLSETPOSIROW) i; /* set the binding location */
 		result = SC_fetch(stmt);
 	}
+	if (SQL_ERROR == result)
+		goto cleanup;
 
 	/* Save the fetch count for SQLSetPos */
 	stmt->last_fetch_count = i;
diff --git a/statement.c b/statement.c
index b7529a3..4a1f657 100644
--- a/statement.c
+++ b/statement.c
@@ -1363,7 +1363,7 @@ inolog("%s statement=%p ommitted=0\n", func, self);
 			return SQL_NO_DATA_FOUND;
 		}
 
-		mylog("**** SC_fetch: non-cursor_result\n");
+		mylog("**** %s: non-cursor_result\n", func);
 		(self->currTuple)++;
 	}
 	else
@@ -1372,7 +1372,7 @@ inolog("%s statement=%p ommitted=0\n", func, self);
 		retval = QR_next_tuple(res, self);
 		if (retval < 0)
 		{
-			mylog("**** SC_fetch: end_tuples\n");
+			mylog("**** %s: end_tuples\n", func);
 			if (QR_get_cursor(res) &&
 			    SQL_CURSOR_FORWARD_ONLY == self->options.cursor_type &&
 			    QR_once_reached_eof(res))
@@ -1383,8 +1383,18 @@ inolog("%s statement=%p ommitted=0\n", func, self);
 			(self->currTuple)++;	/* all is well */
 		else
 		{
-			mylog("SC_fetch: error\n");
-			SC_set_error(self, STMT_EXEC_ERROR, "Error fetching next row", func);
+			ConnectionClass *conn = SC_get_conn(self);
+
+			mylog("%s: error\n", func);
+			switch (conn->status)
+			{
+				case CONN_NOT_CONNECTED:
+				case CONN_DOWN:
+					SC_set_error(self, STMT_BAD_ERROR, "Error fetching next row", func);
+					break;
+				default:
+					SC_set_error(self, STMT_EXEC_ERROR, "Error fetching next row", func);
+			}
 			return SQL_ERROR;
 		}
 	}
-- 
2.39.5