From ab32b2772df33c98ac2f74d0b981a9f600640a75 Mon Sep 17 00:00:00 2001
From: Brian Aker <brian@gaz>
Date: Mon, 28 Jun 2010 13:58:49 -0700
Subject: [PATCH] Small error correction to write/read error logging.

---
 ChangeLog         |  1 +
 libmemcached/io.c | 39 ++++++++++++++++++++++-----------------
 2 files changed, 23 insertions(+), 17 deletions(-)

diff --git a/ChangeLog b/ChangeLog
index 6686efe7..13716ca0 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -2,6 +2,7 @@
   * Added --file for memcat.
   * Added limemcached_ping() to libmemcached_util
   * Bugfix for some cases where connect would have issues with timeout.
+  * Wrong value for errno given as error on an IO failure inside of poll.
 
 0.40 Thu Apr 22 19:01:25 PDT 2010
   * Placed retry logic in for busted resolvers
diff --git a/libmemcached/io.c b/libmemcached/io.c
index d6129b85..30a2a1a4 100644
--- a/libmemcached/io.c
+++ b/libmemcached/io.c
@@ -62,45 +62,50 @@ static memcached_return_t io_wait(memcached_server_write_instance_st ptr,
     timeout= -1;
 
   size_t loop_max= 5;
-  while (--loop_max)
+  while (--loop_max) // While loop is for ERESTART or EINTR
   {
     error= poll(&fds, 1, timeout);
 
     switch (error)
     {
-    case 1:
+    case 1: // Success!
       WATCHPOINT_IF_LABELED_NUMBER(read_or_write && loop_max < 4, "read() times we had to loop, decremented down from 5", loop_max);
       WATCHPOINT_IF_LABELED_NUMBER(!read_or_write && loop_max < 4, "write() times we had to loop, decremented down from 5", loop_max);
 
       return MEMCACHED_SUCCESS;
-    case 0:
+    case 0: // Timeout occured, we let the while() loop do its thing.
       return MEMCACHED_TIMEOUT;
     default:
       WATCHPOINT_ERRNO(errno);
+      switch (errno)
       {
-        switch (errno)
-        {
 #ifdef TARGET_OS_LINUX
-        case ERESTART:
+      case ERESTART:
 #endif
-        case EINTR:
-          continue;
-        default:
-          ptr->cached_errno= error;
-          memcached_quit_server(ptr, true);
-
-          return MEMCACHED_FAILURE;
+      case EINTR:
+        break;
+      default:
+        if (fds.revents & POLLERR)
+        {
+          int err;
+          socklen_t len= sizeof (err);
+          (void)getsockopt(ptr->fd, SOL_SOCKET, SO_ERROR, &err, &len);
+          ptr->cached_errno= (err == 0) ? errno : err;
         }
+        else
+        {
+          ptr->cached_errno= errno;
+        }
+        memcached_quit_server(ptr, true);
+
+        return MEMCACHED_FAILURE;
       }
     }
   }
 
-  if (loop_max == 0 && error == 0)
-    return MEMCACHED_TIMEOUT;
-
   /* Imposssible for anything other then -1 */
   WATCHPOINT_ASSERT(error == -1);
-  ptr->cached_errno= error;
+  ptr->cached_errno= errno;
   memcached_quit_server(ptr, true);
 
   return MEMCACHED_FAILURE;
-- 
2.30.2