Remove redundant null pointer checks before PQclear and PQconninfoFree

These functions already had the free()-like behavior of handling null
pointers as a no-op.  But it wasn't documented, so add it explicitly
to the documentation, too.

Discussion: https://www.postgresql.org/message-id/flat/dac5d2d0-98f5-94d9-8e69-46da2413593d%40enterprisedb.com

4 files changed, 7 insertions, 14 deletions

diff --git a/src/interfaces/ecpg/ecpglib/descriptor.c b/src/interfaces/ecpg/ecpglib/descriptor.c
index f1898dec6a6..649a71c286c 100644
--- a/src/interfaces/ecpg/ecpglib/descriptor.c
+++ b/src/interfaces/ecpg/ecpglib/descriptor.c
@@ -923,8 +923,7 @@ ECPGdescribe(int line, int compat, bool input, const char *connection_name, cons
 					if (!ecpg_check_PQresult(res, line, con->connection, compat))
 						break;
 
-					if (desc->result != NULL)
-						PQclear(desc->result);
+					PQclear(desc->result);
 
 					desc->result = res;
 					ret = true;
diff --git a/src/interfaces/ecpg/ecpglib/execute.c b/src/interfaces/ecpg/ecpglib/execute.c
index 2ebe6656d63..bd94bd4e6c6 100644
--- a/src/interfaces/ecpg/ecpglib/execute.c
+++ b/src/interfaces/ecpg/ecpglib/execute.c
@@ -1714,8 +1714,7 @@ ecpg_process_output(struct statement *stmt, bool clear_result)
 					status = false;
 				else
 				{
-					if (desc->result)
-						PQclear(desc->result);
+					PQclear(desc->result);
 					desc->result = stmt->results;
 					clear_result = false;
 					ecpg_log("ecpg_process_output on line %d: putting result (%d tuples) into descriptor %s\n",
diff --git a/src/interfaces/libpq/fe-connect.c b/src/interfaces/libpq/fe-connect.c
index 057c9da0ede..dc49387d6c5 100644
--- a/src/interfaces/libpq/fe-connect.c
+++ b/src/interfaces/libpq/fe-connect.c
@@ -3766,8 +3766,7 @@ keep_going:						/* We will come back to here until there is
 				}
 
 				/* Something went wrong with "SHOW transaction_read_only". */
-				if (res)
-					PQclear(res);
+				PQclear(res);
 
 				/* Append error report to conn->errorMessage. */
 				appendPQExpBuffer(&conn->errorMessage,
@@ -3818,8 +3817,7 @@ keep_going:						/* We will come back to here until there is
 				}
 
 				/* Something went wrong with "SELECT pg_is_in_recovery()". */
-				if (res)
-					PQclear(res);
+				PQclear(res);
 
 				/* Append error report to conn->errorMessage. */
 				appendPQExpBuffer(&conn->errorMessage,
diff --git a/src/interfaces/libpq/fe-exec.c b/src/interfaces/libpq/fe-exec.c
index 1750d647a8d..51e9a362f6a 100644
--- a/src/interfaces/libpq/fe-exec.c
+++ b/src/interfaces/libpq/fe-exec.c
@@ -775,12 +775,10 @@ PQclear(PGresult *res)
 void
 pqClearAsyncResult(PGconn *conn)
 {
-	if (conn->result)
-		PQclear(conn->result);
+	PQclear(conn->result);
 	conn->result = NULL;
 	conn->error_result = false;
-	if (conn->next_result)
-		PQclear(conn->next_result);
+	PQclear(conn->next_result);
 	conn->next_result = NULL;
 }
 
@@ -2437,8 +2435,7 @@ PQexecFinish(PGconn *conn)
 	lastResult = NULL;
 	while ((result = PQgetResult(conn)) != NULL)
 	{
-		if (lastResult)
-			PQclear(lastResult);
+		PQclear(lastResult);
 		lastResult = result;
 		if (result->resultStatus == PGRES_COPY_IN ||
 			result->resultStatus == PGRES_COPY_OUT ||