Handle UI's terminal closing

Without this, GDB exits if a secondary UIs terminal/input stream is
closed:

 $ ./gdb -ex "new-ui mi /dev/pts/6"
 New UI allocated
	 <<< close /dev/pts/6
 (gdb) Error detected on fd 9
 $

We want that for the main UI, but not secondary UIs.

gdb/ChangeLog:
2016-06-21  Pedro Alves  <palves@redhat.com>

	* event-top.c (stdin_event_handler): Don't quit gdb if it was a
	secondary UI's input stream that closed.  Instead, just delete the
	UI.

1 files changed, 31 insertions, 0 deletions

diff --git a/gdb/top.c b/gdb/top.c
index c5e237d..5883875 100644
--- a/gdb/top.c
+++ b/gdb/top.c
@@ -286,6 +286,37 @@ new_ui (FILE *instream, FILE *outstream, FILE *errstream)
   return ui;
 }
 
+static void
+free_ui (struct ui *ui)
+{
+  ui_file_delete (ui->m_gdb_stdin);
+  ui_file_delete (ui->m_gdb_stdout);
+  ui_file_delete (ui->m_gdb_stderr);
+
+  xfree (ui);
+}
+
+void
+delete_ui (struct ui *todel)
+{
+  struct ui *ui, *uiprev;
+
+  uiprev = NULL;
+
+  for (ui = ui_list; ui != NULL; uiprev = ui, ui = ui->next)
+    if (ui == todel)
+      break;
+
+  gdb_assert (ui != NULL);
+
+  if (uiprev != NULL)
+    uiprev->next = ui->next;
+  else
+    ui_list = ui->next;
+
+  free_ui (ui);
+}
+
 /* Handler for SIGHUP.  */
 
 #ifdef SIGHUP