2 files changed, 9 insertions, 0 deletions

diff --git a/src/ChangeLog b/src/ChangeLog
index 335938916cf..75cb5704059 100644
--- a/src/ChangeLog
+++ b/src/ChangeLog
@@ -2,6 +2,9 @@
 
         * process.c (add_keyboard_wait_descriptor)
         (delete_keyboard_wait_descriptor): Reinstate ifdef subprocesses.
+        (wait_reading_process_output): Don't pass write_mask to select
+        if SELECT_CANT_DO_WRITE_MASK is defined.
+        (SELECT_CANT_DO_WRITE_MASK): Define if SELECT_CANT_DO_WRITE_MASK.
 
         * process.h (add_read_fd, delete_read_fd, add_write_fd)
         (delete_write_fd): Declare.
diff --git a/src/process.c b/src/process.c
index d29168bcfd1..70cc8250add 100644
--- a/src/process.c
+++ b/src/process.c
@@ -201,8 +201,10 @@ int update_tick;
 
 /* Define NON_BLOCKING_CONNECT if we can support non-blocking connects.  */
 
+/* Only W32 has this, it really means that select can't take write mask.  */
 #ifdef BROKEN_NON_BLOCKING_CONNECT
 #undef NON_BLOCKING_CONNECT
+#define SELECT_CANT_DO_WRITE_MASK
 #else
 #ifndef NON_BLOCKING_CONNECT
 #ifdef HAVE_SELECT
@@ -4726,7 +4728,11 @@ wait_reading_process_output (int time_limit, int microsecs, int read_kbd,
           else
             Available = input_wait_mask;
           Writeok = write_mask;
+#ifdef SELECT_CANT_DO_WRITE_MASK
+          check_write = 0;
+#else
           check_write = 1;
+#endif
           check_delay = wait_channel >= 0 ? 0 : process_output_delay_count;
         }