From 8f039cc2055a96d9660a0856f1448bf016d5ecb2 Mon Sep 17 00:00:00 2001
From: "Enrico Weigelt, metux IT consult" <info@metux.net>
Date: Fri, 7 Nov 2025 15:33:54 +0100
Subject: [PATCH] os: replace ETEST macro by ossock_wouldblock()

Move this to a little function (which also has a better name now)
inside the already platform specific ossock.c

Also removing the EMSGSIZE check: we're using TCP or local unix
socket, so EMSGSIZE is never returned.

Signed-off-by: Enrico Weigelt, metux IT consult <info@metux.net>
---
 os/WaitFor.c     |  3 ++-
 os/inputthread.c |  3 ++-
 os/io.c          |  9 +++------
 os/osdep.h       | 14 --------------
 os/ossock.c      |  9 +++++++++
 os/ossock.h      |  5 +++++
 6 files changed, 21 insertions(+), 22 deletions(-)

diff --git a/os/WaitFor.c b/os/WaitFor.c
index ed86839dad..992962df4b 100644
--- a/os/WaitFor.c
+++ b/os/WaitFor.c
@@ -66,6 +66,7 @@ SOFTWARE.
 #include "dix/screensaver_priv.h"
 #include "os/busfault.h"
 #include "os/client_priv.h"
+#include "os/ossock.h"
 #include "os/screensaver.h"
 
 #include "misc.h"
@@ -210,7 +211,7 @@ WaitForSomething(Bool are_ready)
             if (dispatchException)
                 return FALSE;
             if (i < 0) {
-                if (pollerr != EINTR && !ETEST(pollerr)) {
+                if (pollerr != EINTR && ossock_wouldblock(pollerr)) {
                     ErrorF("WaitForSomething(): poll: %s\n",
                            strerror(pollerr));
                 }
diff --git a/os/inputthread.c b/os/inputthread.c
index ea43bf1c30..07399a113e 100644
--- a/os/inputthread.c
+++ b/os/inputthread.c
@@ -36,6 +36,7 @@
 #include "dix/input_priv.h"
 #include "os/ddx_priv.h"
 #include "os/log_priv.h"
+#include "os/ossock.h"
 
 #include "inputstr.h"
 #include "opaque.h"
@@ -148,7 +149,7 @@ InputThreadFillPipe(int writeHead)
 
     do {
         ret = write(writeHead, &byte, 1);
-    } while (ret < 0 && ETEST(errno));
+    } while (ret < 0 && ossock_wouldblock(errno));
 }
 
 /**
diff --git a/os/io.c b/os/io.c
index 8c5d60e29b..d6be03f1e3 100644
--- a/os/io.c
+++ b/os/io.c
@@ -76,6 +76,7 @@ SOFTWARE.
 #include "os/bug_priv.h"
 #include "os/client_priv.h"
 #include "os/osdep.h"
+#include "os/ossock.h"
 
 #include "os.h"
 #include "opaque.h"
@@ -360,7 +361,7 @@ ReadRequestFromClient(ClientPtr client)
         result = _XSERVTransRead(oc->trans_conn, oci->buffer + oci->bufcnt,
                                  oci->size - oci->bufcnt);
         if (result <= 0) {
-            if ((result < 0) && ETEST(errno)) {
+            if ((result < 0) && ossock_wouldblock(errno)) {
                 mark_client_not_ready(client);
                 YieldControlNoInput(client);
                 return 0;
@@ -937,11 +938,7 @@ FlushClient(ClientPtr who, OsCommPtr oc)
             notWritten -= len;
             todo = notWritten;
         }
-        else if (ETEST(errno)
-#ifdef EMSGSIZE                 /* check for another brain-damaged OS bug */
-                 || ((errno == EMSGSIZE) && (todo == 1))
-#endif
-            ) {
+        else if (ossock_wouldblock(errno)) {
             /* If we've arrived here, then the client is stuffed to the gills
                and not ready to accept more.  Make a note of it and buffer
                the rest. */
diff --git a/os/osdep.h b/os/osdep.h
index 5ea06c547a..f63b93c1ee 100644
--- a/os/osdep.h
+++ b/os/osdep.h
@@ -61,20 +61,6 @@ SOFTWARE.
 # define __has_builtin(x) 0     /* Compatibility with older compilers */
 #endif
 
-/* If EAGAIN and EWOULDBLOCK are distinct errno values, then we check errno
- * for both EAGAIN and EWOULDBLOCK, because some supposedly POSIX
- * systems are broken and return EWOULDBLOCK when they should return EAGAIN
- */
-#ifndef WIN32
-# if (EAGAIN != EWOULDBLOCK)
-#  define ETEST(err) (err == EAGAIN || err == EWOULDBLOCK)
-# else
-#  define ETEST(err) (err == EAGAIN)
-# endif
-#else   /* WIN32 The socket errorcodes differ from the normal errors */
-#define ETEST(err) (err == EAGAIN || err == WSAEWOULDBLOCK)
-#endif
-
 typedef struct _connectionInput *ConnectionInputPtr;
 typedef struct _connectionOutput *ConnectionOutputPtr;
 
diff --git a/os/ossock.c b/os/ossock.c
index f9cac0151d..68e1cdb29e 100644
--- a/os/ossock.c
+++ b/os/ossock.c
@@ -46,3 +46,12 @@ int ossock_close(int fd)
     return close(fd);
 #endif
 }
+
+int ossock_wouldblock(int err)
+{
+#ifdef WIN32
+    return ((err == EAGAIN) || (err == WSAEWOULDBLOCK));
+#else
+    return ((err == EAGAIN) || (err == EWOULDBLOCK));
+#endif
+}
diff --git a/os/ossock.h b/os/ossock.h
index 254ed5d083..b2475285b8 100644
--- a/os/ossock.h
+++ b/os/ossock.h
@@ -22,4 +22,9 @@ int ossock_ioctl(int fd, unsigned long request, void *arg);
  */
 int ossock_close(int fd);
 
+/*
+ * os specific check for errno indicating operation would block
+ */
+int ossock_wouldblock(int err);
+
 #endif /* _XSERVER_OS_OSSOCK_H_ */