[PATCH v2 23/25] Handle UI terminal closed

[Pedro Alves <palves@redhat.com>]

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/event-top.c | 25 ++++++++++++++++++-------
 gdb/top.c       | 31 +++++++++++++++++++++++++++++++
 gdb/top.h       |  1 +
 3 files changed, 50 insertions(+), 7 deletions(-)

diff --git a/gdb/event-top.c b/gdb/event-top.c
index 69f6be7..39b9633 100644
--- a/gdb/event-top.c
+++ b/gdb/event-top.c
@@ -420,19 +420,30 @@ stdin_event_handler (int error, gdb_client_data client_data)
 {
   struct ui *ui = (struct ui *) client_data;
 
-  /* Switch to the UI whose input descriptor woke up the event
-     loop.  */
-  current_ui = ui;
-
   if (error)
     {
-      printf_unfiltered (_("error detected on stdin\n"));
+      /* Switch to the main UI, so diagnostics always go there.  */
+      current_ui = main_ui;
+
       delete_file_handler (ui->input_fd);
-      /* If stdin died, we may as well kill gdb.  */
-      quit_command ((char *) 0, stdin == ui->instream);
+      if (main_ui == ui)
+	{
+	  /* If stdin died, we may as well kill gdb.  */
+	  printf_unfiltered (_("error detected on stdin\n"));
+	  quit_command ((char *) 0, stdin == ui->instream);
+	}
+      else
+	{
+	  /* Simply delete the UI.  */
+	  delete_ui (ui);
+	}
     }
   else
     {
+      /* Switch to the UI whose input descriptor woke up the event
+	 loop.  */
+      current_ui = ui;
+
       do
 	{
 	  call_stdin_event_handler_again_p = 0;
diff --git a/gdb/top.c b/gdb/top.c
index 12064bc..7d6d7cb 100644
--- a/gdb/top.c
+++ b/gdb/top.c
@@ -282,6 +282,37 @@ 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
diff --git a/gdb/top.h b/gdb/top.h
index df76204..bac5a33 100644
--- a/gdb/top.h
+++ b/gdb/top.h
@@ -161,6 +161,7 @@ extern void switch_thru_all_uis_next (struct switch_thru_all_uis *state);
   for (UI = ui_list; UI; UI = UI->next)		\
 
 extern struct ui *new_ui (FILE *instream, FILE *outstream, FILE *errstream);
+extern void delete_ui (struct ui *todel);
 
 extern void restore_ui_cleanup (void *data);
 
-- 
2.5.0