diff --git a/src/interfaces/libpq/fe-auth.c b/src/interfaces/libpq/fe-auth.c
index 7e9afbbeee..bde5966f87 100644
--- a/src/interfaces/libpq/fe-auth.c
+++ b/src/interfaces/libpq/fe-auth.c
@@ -453,7 +453,11 @@ pg_SASL_init(PGconn *conn, int payloadlen)
 			goto error;
 		}
 		if (PQExpBufferDataBroken(mechanism_buf))
-			goto oom_error;
+		{
+	        printfPQExpBuffer(&conn->errorMessage,
+					          libpq_gettext("out of memory\n"));
+			goto error;
+		}
 
 		/* An empty string indicates end of list */
 		if (mechanism_buf.data[0] == '\0')
@@ -561,7 +565,11 @@ pg_SASL_init(PGconn *conn, int payloadlen)
 										password,
 										selected_mechanism);
 	if (!conn->sasl_state)
-		goto oom_error;
+    {
+	    printfPQExpBuffer(&conn->errorMessage,
+			              libpq_gettext("out of memory\n"));		
+		goto error;
+	}
 
 	/* Get the mechanism-specific Initial Client Response, if any */
 	pg_fe_scram_exchange(conn->sasl_state,
@@ -601,14 +609,7 @@ error:
 	termPQExpBuffer(&mechanism_buf);
 	if (initialresponse)
 		free(initialresponse);
-	return STATUS_ERROR;
 
-oom_error:
-	termPQExpBuffer(&mechanism_buf);
-	if (initialresponse)
-		free(initialresponse);
-	printfPQExpBuffer(&conn->errorMessage,
-					  libpq_gettext("out of memory\n"));
 	return STATUS_ERROR;
 }
 
diff --git a/src/interfaces/libpq/fe-exec.c b/src/interfaces/libpq/fe-exec.c
index eea0237c3a..ed8ff5b830 100644
--- a/src/interfaces/libpq/fe-exec.c
+++ b/src/interfaces/libpq/fe-exec.c
@@ -69,7 +69,7 @@ static bool PQexecStart(PGconn *conn);
 static PGresult *PQexecFinish(PGconn *conn);
 static int	PQsendDescribe(PGconn *conn, char desc_type,
 						   const char *desc_target);
-static int	check_field_number(const PGresult *res, int field_num);
+static bool	check_field_number(const PGresult *res, int field_num);
 
 
 /* ----------------
@@ -225,7 +225,7 @@ PQmakeEmptyPGresult(PGconn *conn, ExecStatusType status)
  * function fails, it returns zero.  If the function succeeds, it
  * returns a non-zero value.
  */
-int
+bool
 PQsetResultAttrs(PGresult *res, int numAttributes, PGresAttDesc *attDescs)
 {
 	int			i;
@@ -427,7 +427,7 @@ dupEvents(PGEvent *events, int count, size_t *memSize)
  * Returns a non-zero value for success and zero for failure.
  * (On failure, we report the specific problem via pqInternalNotice.)
  */
-int
+bool
 PQsetvalue(PGresult *res, int tup_num, int field_num, char *value, int len)
 {
 	PGresAttValue *attval;
@@ -694,27 +694,29 @@ void
 PQclear(PGresult *res)
 {
 	PGresult_data *block;
-	int			i;
 
 	if (!res)
 		return;
 
-	for (i = 0; i < res->nEvents; i++)
+	if (res->events)
 	{
-		/* only send DESTROY to successfully-initialized event procs */
-		if (res->events[i].resultInitialized)
-		{
-			PGEventResultDestroy evt;
+	    int	i;
 
-			evt.result = res;
-			(void) res->events[i].proc(PGEVT_RESULTDESTROY, &evt,
-									   res->events[i].passThrough);
-		}
-		free(res->events[i].name);
-	}
+	    for (i = 0; i < res->nEvents; i++)
+	    {
+		     /* only send DESTROY to successfully-initialized event procs */
+		     if (res->events[i].resultInitialized)
+		     {
+			     PGEventResultDestroy evt;
 
-	if (res->events)
+			     evt.result = res;
+			     (void) res->events[i].proc(PGEVT_RESULTDESTROY, &evt,
+				   					        res->events[i].passThrough);
+		     }
+		     free(res->events[i].name);
+		}
 		free(res->events);
+	}
 
 	/* Free all the subsidiary blocks */
 	while ((block = res->curBlock) != NULL)
@@ -1233,9 +1235,6 @@ fail:
 int
 PQsendQuery(PGconn *conn, const char *query)
 {
-	if (!PQsendQueryStart(conn))
-		return 0;
-
 	/* check the argument */
 	if (!query)
 	{
@@ -1243,6 +1242,8 @@ PQsendQuery(PGconn *conn, const char *query)
 						  libpq_gettext("command string is a null pointer\n"));
 		return 0;
 	}
+	if (!PQsendQueryStart(conn))
+		return 0;
 
 	/* construct the outgoing Query message */
 	if (pqPutMsgStart('Q', false, conn) < 0 ||
@@ -1291,9 +1292,6 @@ PQsendQueryParams(PGconn *conn,
 				  const int *paramFormats,
 				  int resultFormat)
 {
-	if (!PQsendQueryStart(conn))
-		return 0;
-
 	/* check the arguments */
 	if (!command)
 	{
@@ -1307,6 +1305,8 @@ PQsendQueryParams(PGconn *conn,
 						  libpq_gettext("number of parameters must be between 0 and 65535\n"));
 		return 0;
 	}
+	if (!PQsendQueryStart(conn))
+		return 0;
 
 	return PQsendQueryGuts(conn,
 						   command,
@@ -1331,9 +1331,6 @@ PQsendPrepare(PGconn *conn,
 			  const char *stmtName, const char *query,
 			  int nParams, const Oid *paramTypes)
 {
-	if (!PQsendQueryStart(conn))
-		return 0;
-
 	/* check the arguments */
 	if (!stmtName)
 	{
@@ -1362,6 +1359,9 @@ PQsendPrepare(PGconn *conn,
 		return 0;
 	}
 
+	if (!PQsendQueryStart(conn))
+		return 0;
+
 	/* construct the Parse message */
 	if (pqPutMsgStart('P', false, conn) < 0 ||
 		pqPuts(stmtName, conn) < 0 ||
@@ -1432,9 +1432,6 @@ PQsendQueryPrepared(PGconn *conn,
 					const int *paramFormats,
 					int resultFormat)
 {
-	if (!PQsendQueryStart(conn))
-		return 0;
-
 	/* check the arguments */
 	if (!stmtName)
 	{
@@ -1449,6 +1446,9 @@ PQsendQueryPrepared(PGconn *conn,
 		return 0;
 	}
 
+	if (!PQsendQueryStart(conn))
+		return 0;
+
 	return PQsendQueryGuts(conn,
 						   NULL,	/* no command to parse */
 						   stmtName,
@@ -2219,13 +2219,6 @@ PQsendDescribePortal(PGconn *conn, const char *portal)
 static int
 PQsendDescribe(PGconn *conn, char desc_type, const char *desc_target)
 {
-	/* Treat null desc_target as empty string */
-	if (!desc_target)
-		desc_target = "";
-
-	if (!PQsendQueryStart(conn))
-		return 0;
-
 	/* This isn't gonna work on a 2.0 server */
 	if (PG_PROTOCOL_MAJOR(conn->pversion) < 3)
 	{
@@ -2234,6 +2227,13 @@ PQsendDescribe(PGconn *conn, char desc_type, const char *desc_target)
 		return 0;
 	}
 
+	if (!PQsendQueryStart(conn))
+		return 0;
+
+	/* Treat null desc_target as empty string */
+	if (!desc_target)
+		desc_target = "";
+
 	/* construct the Describe message */
 	if (pqPutMsgStart('D', false, conn) < 0 ||
 		pqPutc(desc_type, conn) < 0 ||
@@ -2794,7 +2794,7 @@ PQbinaryTuples(const PGresult *res)
  * Return true if OK, false if not
  */
 
-static int
+static bool
 check_field_number(const PGresult *res, int field_num)
 {
 	if (!res)
@@ -2809,7 +2809,7 @@ check_field_number(const PGresult *res, int field_num)
 	return true;
 }
 
-static int
+static bool
 check_tuple_field_number(const PGresult *res,
 						 int tup_num, int field_num)
 {
@@ -2832,7 +2832,7 @@ check_tuple_field_number(const PGresult *res,
 	return true;
 }
 
-static int
+static bool
 check_param_number(const PGresult *res, int param_num)
 {
 	if (!res)
diff --git a/src/interfaces/libpq/libpq-fe.h b/src/interfaces/libpq/libpq-fe.h
index c9e6ac2b76..c7794a9a1f 100644
--- a/src/interfaces/libpq/libpq-fe.h
+++ b/src/interfaces/libpq/libpq-fe.h
@@ -524,10 +524,10 @@ extern void PQfreemem(void *ptr);
 /* Create and manipulate PGresults */
 extern PGresult *PQmakeEmptyPGresult(PGconn *conn, ExecStatusType status);
 extern PGresult *PQcopyResult(const PGresult *src, int flags);
-extern int	PQsetResultAttrs(PGresult *res, int numAttributes, PGresAttDesc *attDescs);
+extern bool	PQsetResultAttrs(PGresult *res, int numAttributes, PGresAttDesc *attDescs);
 extern void *PQresultAlloc(PGresult *res, size_t nBytes);
 extern size_t PQresultMemorySize(const PGresult *res);
-extern int	PQsetvalue(PGresult *res, int tup_num, int field_num, char *value, int len);
+extern bool	PQsetvalue(PGresult *res, int tup_num, int field_num, char *value, int len);
 
 /* Quoting strings before inclusion in queries. */
 extern size_t PQescapeStringConn(PGconn *conn,