ntdll: Preserve errno across system calls done in the suspend handler.

dlls/ntdll/exception.c

@@ -23,6 +23,7 @@
 #include "wine/port.h"
 
 #include <assert.h>
+#include <errno.h>
 #include <signal.h>
 #include <stdarg.h>
 
@@ -147,6 +148,7 @@ extern DWORD EXC_CallHandler( EXCEPTION_RECORD *record, EXCEPTION_REGISTRATION_R
 void wait_suspend( CONTEXT *context )
 {
     LARGE_INTEGER timeout;
+    int saved_errno = errno;
 
     /* store the context we got at suspend time */
     SERVER_START_REQ( set_thread_context )
@@ -173,6 +175,8 @@ void wait_suspend( CONTEXT *context )
         wine_server_call( req );
     }
     SERVER_END_REQ;
+
+    errno = saved_errno;
 }