Fix documentation for libpq's PQfn().

The SGML docs claimed that 1-byte integers could be sent or received with
the "isint" options, but no such behavior has ever been implemented in
pqGetInt() or pqPutInt().  The in-code documentation header for PQfn() was
even less in tune with reality, and the code itself used parameter names
matching neither the SGML docs nor its libpq-fe.h declaration.  Do a bit
of additional wordsmithing on the SGML docs while at it.

Since the business about 1-byte integers is a clear documentation bug,
back-patch to all supported branches.

1 files changed, 10 insertions, 12 deletions

diff --git a/src/interfaces/libpq/fe-exec.c b/src/interfaces/libpq/fe-exec.c
index 3d46e150678..828f18e1110 100644
--- a/src/interfaces/libpq/fe-exec.c
+++ b/src/interfaces/libpq/fe-exec.c
@@ -2514,20 +2514,18 @@ PQendcopy(PGconn *conn)
  *		PQfn -	Send a function call to the POSTGRES backend.
  *
  *		conn			: backend connection
- *		fnid			: function id
- *		result_buf		: pointer to result buffer (&int if integer)
- *		result_len		: length of return value.
- *		actual_result_len: actual length returned. (differs from result_len
- *						  for varlena structures.)
- *		result_type		: If the result is an integer, this must be 1,
+ *		fnid			: OID of function to be called
+ *		result_buf		: pointer to result buffer
+ *		result_len		: actual length of result is returned here
+ *		result_is_int	: If the result is an integer, this must be 1,
  *						  otherwise this should be 0
- *		args			: pointer to an array of function arguments.
+ *		args			: pointer to an array of function arguments
  *						  (each has length, if integer, and value/pointer)
  *		nargs			: # of arguments in args array.
  *
  * RETURNS
  *		PGresult with status = PGRES_COMMAND_OK if successful.
- *			*actual_result_len is > 0 if there is a return value, 0 if not.
+ *			*result_len is > 0 if there is a return value, 0 if not.
  *		PGresult with status = PGRES_FATAL_ERROR if backend returns an error.
  *		NULL on communications failure.  conn->errorMessage will be set.
  * ----------------
@@ -2537,12 +2535,12 @@ PGresult *
 PQfn(PGconn *conn,
 	 int fnid,
 	 int *result_buf,
-	 int *actual_result_len,
+	 int *result_len,
 	 int result_is_int,
 	 const PQArgBlock *args,
 	 int nargs)
 {
-	*actual_result_len = 0;
+	*result_len = 0;
 
 	if (!conn)
 		return NULL;
@@ -2560,12 +2558,12 @@ PQfn(PGconn *conn,
 
 	if (PG_PROTOCOL_MAJOR(conn->pversion) >= 3)
 		return pqFunctionCall3(conn, fnid,
-							   result_buf, actual_result_len,
+							   result_buf, result_len,
 							   result_is_int,
 							   args, nargs);
 	else
 		return pqFunctionCall2(conn, fnid,
-							   result_buf, actual_result_len,
+							   result_buf, result_len,
 							   result_is_int,
 							   args, nargs);
 }