From bc699ace15fc2dd2cc7ff022fa9ec6031ba09d13 Mon Sep 17 00:00:00 2001
From: ReinUsesLisp <reinuseslisp@airmail.cc>
Date: Tue, 28 Jul 2020 01:51:44 -0300
Subject: [PATCH] service/bsd: Handle Poll with no entries accurately

Testing shows that Poll called with zero entries returns -1 and signals
an errno of zero.
---
 src/core/hle/service/sockets/bsd.cpp | 5 +++++
 1 file changed, 5 insertions(+)

diff --git a/src/core/hle/service/sockets/bsd.cpp b/src/core/hle/service/sockets/bsd.cpp
index 1d20f33a4..803505452 100644
--- a/src/core/hle/service/sockets/bsd.cpp
+++ b/src/core/hle/service/sockets/bsd.cpp
@@ -465,6 +465,11 @@ std::pair<s32, Errno> BSD::PollImpl(std::vector<u8>& write_buffer, std::vector<u
         return {-1, Errno::INVAL};
     }
 
+    if (nfds == 0) {
+        // When no entries are provided, -1 is returned with errno zero
+        return {-1, Errno::SUCCESS};
+    }
+
     const size_t length = std::min(read_buffer.size(), write_buffer.size());
     std::vector<PollFD> fds(nfds);
     std::memcpy(fds.data(), read_buffer.data(), length);