From ab38e6cebb7765e1fe0ce846e2a30deab285e7d2 Mon Sep 17 00:00:00 2001
From: Monster Iestyn <iestynjealous@ntlworld.com>
Date: Sat, 13 Oct 2018 20:44:01 +0100
Subject: [PATCH 1/5] Creating a quick get_WSAErrorStr function to act as a
 wrapper for FormatMessageA so we can string-ify Winsock errors properly

Untested!
---
 src/i_tcp.c | 22 ++++++++++++++++++++++
 1 file changed, 22 insertions(+)

diff --git a/src/i_tcp.c b/src/i_tcp.c
index 6488e9845..9febd56f0 100644
--- a/src/i_tcp.c
+++ b/src/i_tcp.c
@@ -262,6 +262,28 @@ static void wattcp_outch(char s)
 }
 #endif
 
+#ifdef USE_WINSOCK
+// stupid microsoft makes things complicated
+static inline char *get_WSAErrorStr(int e)
+{
+	char *buf = NULL;
+
+	FormatMessageA(
+		FORMAT_MESSAGE_ALLOCATE_BUFFER |
+		FORMAT_MESSAGE_FROM_SYSTEM |
+		FORMAT_MESSAGE_IGNORE_INSERTS,
+		NULL,
+		(DWORD)e,
+		MAKELANGID(LANG_NEUTRAL, SUBLANG_DEFAULT),
+		(LPTSTR)&buf,
+		0, NULL);
+
+	return buf;
+}
+#undef strerror
+#define strerror get_WSAErrorStr
+#endif
+
 #ifdef USE_WINSOCK2
 #define inet_ntop inet_ntopA
 #define HAVE_NTOP

From 3b39a25adec80437e56f8a6d886d220786a889f6 Mon Sep 17 00:00:00 2001
From: Monster Iestyn <iestynjealous@ntlworld.com>
Date: Sat, 27 Oct 2018 15:49:04 +0100
Subject: [PATCH 2/5] Save the result of errno (aka WSAGetLastError() for
 WinSock) as soon as possible, to prevent anything in SOCK_GetNodeAddress
 resetting the value to 0 while trying to print the message for the error
 itself!

---
 src/i_tcp.c | 10 +++++++---
 1 file changed, 7 insertions(+), 3 deletions(-)

diff --git a/src/i_tcp.c b/src/i_tcp.c
index 9febd56f0..6a2127866 100644
--- a/src/i_tcp.c
+++ b/src/i_tcp.c
@@ -781,9 +781,13 @@ static void SOCK_Send(void)
 			&clientaddress[doomcom->remotenode].any, d);
 	}
 
-	if (c == ERRSOCKET && errno != ECONNREFUSED && errno != EWOULDBLOCK)
-		I_Error("SOCK_Send, error sending to node %d (%s) #%u: %s", doomcom->remotenode,
-			SOCK_GetNodeAddress(doomcom->remotenode), errno, strerror(errno));
+	if (c == ERRSOCKET)
+	{
+		int e = errno; // save error code so it can't be modified later
+		if (e != ECONNREFUSED && e != EWOULDBLOCK)
+			I_Error("SOCK_Send, error sending to node %d (%s) #%u: %s", doomcom->remotenode,
+				SOCK_GetNodeAddress(doomcom->remotenode), e, strerror(e));
+	}
 }
 #endif
 

From e4e76f83c3e6c4de8ac467667df7daf05d2d9582 Mon Sep 17 00:00:00 2001
From: Monster Iestyn <iestynjealous@ntlworld.com>
Date: Sat, 27 Oct 2018 16:09:14 +0100
Subject: [PATCH 3/5] Use temporary buffer with a max size of 255 bytes instead
 of having Microsoft's FormatMessageA alloc one for us. Also, provide a
 fallback message in case no message was available for some reason

---
 src/i_tcp.c | 13 +++++++++----
 1 file changed, 9 insertions(+), 4 deletions(-)

diff --git a/src/i_tcp.c b/src/i_tcp.c
index 6a2127866..c054b3a4a 100644
--- a/src/i_tcp.c
+++ b/src/i_tcp.c
@@ -266,17 +266,22 @@ static void wattcp_outch(char s)
 // stupid microsoft makes things complicated
 static inline char *get_WSAErrorStr(int e)
 {
-	char *buf = NULL;
+	char buf[256]; // allow up to 255 bytes
+
+	buf[0] = '\0';
 
 	FormatMessageA(
-		FORMAT_MESSAGE_ALLOCATE_BUFFER |
 		FORMAT_MESSAGE_FROM_SYSTEM |
 		FORMAT_MESSAGE_IGNORE_INSERTS,
 		NULL,
 		(DWORD)e,
 		MAKELANGID(LANG_NEUTRAL, SUBLANG_DEFAULT),
-		(LPTSTR)&buf,
-		0, NULL);
+		(LPTSTR)buf,
+		sizeof (buf),
+		NULL);
+
+	if (!buf[0]) // provide a fallback error message if no message is available for some reason
+		sprintf(buf, "Unknown error");
 
 	return buf;
 }

From bb3d850bbfaf9fe9c333e1c0c4a79706ec878c8c Mon Sep 17 00:00:00 2001
From: Monster Iestyn <iestynjealous@ntlworld.com>
Date: Sat, 27 Oct 2018 16:27:00 +0100
Subject: [PATCH 4/5] static the buffer, forgot to do this earlier

---
 src/i_tcp.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/src/i_tcp.c b/src/i_tcp.c
index c054b3a4a..43dba4aa3 100644
--- a/src/i_tcp.c
+++ b/src/i_tcp.c
@@ -266,7 +266,7 @@ static void wattcp_outch(char s)
 // stupid microsoft makes things complicated
 static inline char *get_WSAErrorStr(int e)
 {
-	char buf[256]; // allow up to 255 bytes
+	static char buf[256]; // allow up to 255 bytes
 
 	buf[0] = '\0';
 

From 9fb301ecb587ed933f300cc9b65f23f8072e9d57 Mon Sep 17 00:00:00 2001
From: Monster Iestyn <iestynjealous@ntlworld.com>
Date: Sat, 27 Oct 2018 16:47:56 +0100
Subject: [PATCH 5/5] don't bother with inlining the function, on second
 thoughts

---
 src/i_tcp.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/src/i_tcp.c b/src/i_tcp.c
index 43dba4aa3..0728c7aac 100644
--- a/src/i_tcp.c
+++ b/src/i_tcp.c
@@ -264,7 +264,7 @@ static void wattcp_outch(char s)
 
 #ifdef USE_WINSOCK
 // stupid microsoft makes things complicated
-static inline char *get_WSAErrorStr(int e)
+static char *get_WSAErrorStr(int e)
 {
 	static char buf[256]; // allow up to 255 bytes