From 5ffc30582835268c78bfe9e6d09911df5c5703fb Mon Sep 17 00:00:00 2001
From: ripley <ripley@00db46b3-68df-0310-9c12-caf00c1e9a41>
Date: Sun, 15 Jan 2017 19:28:20 +0000
Subject: [PATCH] add comment

git-svn-id: https://svn.r-project.org/R/trunk@71977 00db46b3-68df-0310-9c12-caf00c1e9a41
---
 src/unix/dynload.c | 5 +++++
 1 file changed, 5 insertions(+)

diff --git a/src/unix/dynload.c b/src/unix/dynload.c
index 226bd14a40a..ca71cb8de70 100644
--- a/src/unix/dynload.c
+++ b/src/unix/dynload.c
@@ -201,6 +201,11 @@ static int computeDLOpenFlag(int asLocal, int now)
   This is the system/OS-specific version for resolving a
   symbol in a shared object.  A cast would not be legal C.
  */
+/*
+  We are not interested in NULL symbols in the shared object.
+  If we were, this would need to use dlerror() before and after
+  dlsym, and check the second value is NULL.
+ */
 typedef union {void *p; DL_FUNC fn;} fn_ptr;
 static DL_FUNC R_local_dlsym(DllInfo *info, char const *name)
 {