gsocket: add G_IO_ERROR_CONNECTION_CLOSED

Add G_IO_ERROR_CONNECTION_CLOSED as an alias for
G_IO_ERROR_BROKEN_PIPE, and also return it on ECONNRESET.

It doesn't really make sense to try to distinguish EPIPE and
ECONNRESET at the GLib level, since the exact choice of which error
gets returned in what conditions depends on the OS. Given that, we
ought to map the two errors to the same value, and since we're already
mapping EPIPE to G_IO_ERROR_BROKEN_PIPE, we need to map ECONNRESET to
that too. But the existing name doesn't really make sense for sockets,
so we add a new name.

https://bugzilla.gnome.org/show_bug.cgi?id=728928

gio/gioenums.h

@@ -470,12 +470,17 @@ typedef enum {
  * @G_IO_ERROR_PROXY_NOT_ALLOWED: Proxy connection is not allowed by ruleset.
  *     Since 2.26
  * @G_IO_ERROR_BROKEN_PIPE: Broken pipe. Since 2.36
+ * @G_IO_ERROR_CONNECTION_CLOSED: Connection closed by peer. Note that this
+ *     is the same code as %G_IO_ERROR_BROKEN_PIPE; before 2.44 some
+ *     "connection closed" errors returned %G_IO_ERROR_BROKEN_PIPE, but others
+ *     returned %G_IO_ERROR_FAILED. Now they should all return the same
+ *     value, which has this more logical name. Since 2.44.
  *
  * Error codes returned by GIO functions.
  *
  * Note that this domain may be extended in future GLib releases. In
  * general, new error codes either only apply to new APIs, or else
- * replace #G_IO_ERROR_FAILED in cases that were not explicitly
+ * replace %G_IO_ERROR_FAILED in cases that were not explicitly
  * distinguished before. You should therefore avoid writing code like
  * |[<!-- language="C" -->
  * if (g_error_matches (error, G_IO_ERROR, G_IO_ERROR_FAILED))
@@ -532,7 +537,8 @@ typedef enum {
   G_IO_ERROR_PROXY_AUTH_FAILED,
   G_IO_ERROR_PROXY_NEED_AUTH,
   G_IO_ERROR_PROXY_NOT_ALLOWED,
-  G_IO_ERROR_BROKEN_PIPE
+  G_IO_ERROR_BROKEN_PIPE,
+  G_IO_ERROR_CONNECTION_CLOSED = G_IO_ERROR_BROKEN_PIPE
 } GIOErrorEnum;
 
 

gio/gioerror.c

@@ -242,6 +242,12 @@ g_io_error_from_errno (gint err_no)
       break;
 #endif
 
+#ifdef ECONNRESET
+    case ECONNRESET:
+      return G_IO_ERROR_CONNECTION_CLOSED;
+      break;
+#endif
+
     default:
       return G_IO_ERROR_FAILED;
       break;
@@ -305,6 +311,9 @@ g_io_error_from_win32_error (gint error_code)
     case WSAEAFNOSUPPORT:
       return G_IO_ERROR_NOT_SUPPORTED;
 
+    case WSAECONNRESET:
+      return G_IO_ERROR_CONNECTION_CLOSED;
+
     default:
       return G_IO_ERROR_FAILED;
     }

gio/tests/socket.c

@@ -317,9 +317,23 @@ test_ip_async (GSocketFamily family)
 
   g_thread_join (data->thread);
 
-  len = g_socket_receive (client, buf, sizeof (buf), NULL, &error);
+  if (family == G_SOCKET_FAMILY_IPV4)
+    {
+      /* Test that reading on a remote-closed socket gets back 0 bytes. */
+      len = g_socket_receive_with_blocking (client, buf, sizeof (buf),
+					    TRUE, NULL, &error);
       g_assert_no_error (error);
       g_assert_cmpint (len, ==, 0);
+    }
+  else
+    {
+      /* Test that writing to a remote-closed socket gets back CONNECTION_CLOSED. */
+      len = g_socket_send_with_blocking (client, testbuf, strlen (testbuf) + 1,
+					 TRUE, NULL, &error);
+      g_assert_error (error, G_IO_ERROR, G_IO_ERROR_CONNECTION_CLOSED);
+      g_assert_cmpint (len, ==, -1);
+      g_clear_error (&error);
+    }
 
   g_socket_close (client, &error);
   g_assert_no_error (error);
@@ -406,9 +420,21 @@ test_ip_sync (GSocketFamily family)
 
   g_thread_join (data->thread);
 
+  if (family == G_SOCKET_FAMILY_IPV4)
+    {
+      /* Test that reading on a remote-closed socket gets back 0 bytes. */
       len = g_socket_receive (client, buf, sizeof (buf), NULL, &error);
       g_assert_no_error (error);
       g_assert_cmpint (len, ==, 0);
+    }
+  else
+    {
+      /* Test that writing to a remote-closed socket gets back CONNECTION_CLOSED. */
+      len = g_socket_send (client, testbuf, strlen (testbuf) + 1, NULL, &error);
+      g_assert_error (error, G_IO_ERROR, G_IO_ERROR_CONNECTION_CLOSED);
+      g_assert_cmpint (len, ==, -1);
+      g_clear_error (&error);
+    }
 
   g_socket_close (client, &error);
   g_assert_no_error (error);