From 7cd425abab020968bb6a8e6d3521b6cf915a24cc Mon Sep 17 00:00:00 2001
From: Simon Tatham <anakin@pobox.com>
Date: Fri, 28 Sep 2018 19:21:37 +0100
Subject: [PATCH] uxproxy: close input pipes that have seen EOF on read.

Otherwise we loop round repeatedly with the event loop continuing to
report the same EOF condition on them over and over again, consuming
CPU pointlessly and probably causing other knock-on trouble too.
---
 unix/uxproxy.c | 45 ++++++++++++++++++++++++++++++++-------------
 1 file changed, 32 insertions(+), 13 deletions(-)

diff --git a/unix/uxproxy.c b/unix/uxproxy.c
index fdf8bce7..c6708343 100644
--- a/unix/uxproxy.c
+++ b/unix/uxproxy.c
@@ -122,13 +122,17 @@ static void sk_localproxy_close (Socket s)
         close(ps->to_cmd);
     }
 
-    del234(localproxy_by_fromfd, ps);
-    uxsel_del(ps->from_cmd);
-    close(ps->from_cmd);
+    if (ps->from_cmd >= 0) {
+        del234(localproxy_by_fromfd, ps);
+        uxsel_del(ps->from_cmd);
+        close(ps->from_cmd);
+    }
 
-    del234(localproxy_by_errfd, ps);
-    uxsel_del(ps->cmd_err);
-    close(ps->cmd_err);
+    if (ps->cmd_err >= 0) {
+        del234(localproxy_by_errfd, ps);
+        uxsel_del(ps->cmd_err);
+        close(ps->cmd_err);
+    }
 
     bufchain_clear(&ps->pending_input_data);
     bufchain_clear(&ps->pending_output_data);
@@ -238,6 +242,9 @@ static void sk_localproxy_set_frozen (Socket s, int is_frozen)
 {
     LocalProxySocket *ps = FROMFIELD(s, LocalProxySocket, sockvt);
 
+    if (ps->from_cmd < 0)
+        return;
+
     if (is_frozen)
 	uxsel_del(ps->from_cmd);
     else
@@ -257,24 +264,36 @@ static void localproxy_select_result(int fd, int event)
     int ret;
 
     if (!(s = find234(localproxy_by_fromfd, &fd, localproxy_fromfd_find)) &&
-	!(s = find234(localproxy_by_fromfd, &fd, localproxy_errfd_find)) &&
+	!(s = find234(localproxy_by_errfd, &fd, localproxy_errfd_find)) &&
 	!(s = find234(localproxy_by_tofd, &fd, localproxy_tofd_find)) )
 	return;		       /* boggle */
 
     if (event == 1) {
         if (fd == s->cmd_err) {
             ret = read(fd, buf, sizeof(buf));
-            if (ret > 0)
+            if (ret > 0) {
                 log_proxy_stderr(s->plug, &s->pending_error_data, buf, ret);
+            } else {
+                del234(localproxy_by_errfd, s);
+                uxsel_del(s->cmd_err);
+                close(s->cmd_err);
+                s->cmd_err = -1;
+            }
         } else {
             assert(fd == s->from_cmd);
             ret = read(fd, buf, sizeof(buf));
-            if (ret < 0) {
-                plug_closing(s->plug, strerror(errno), errno, 0);
-            } else if (ret == 0) {
-                plug_closing(s->plug, NULL, 0, 0);
-            } else {
+            if (ret > 0) {
                 plug_receive(s->plug, 0, buf, ret);
+            } else {
+                if (ret < 0) {
+                    plug_closing(s->plug, strerror(errno), errno, 0);
+                } else {
+                    plug_closing(s->plug, NULL, 0, 0);
+                }
+                del234(localproxy_by_fromfd, s);
+                uxsel_del(s->from_cmd);
+                close(s->from_cmd);
+                s->from_cmd = -1;
             }
         }
     } else if (event == 2) {