7 files changed, 98 insertions, 9 deletions
diff --git a/gdb/ChangeLog b/gdb/ChangeLog
index 229a62b..0d875c8 100644
--- a/gdb/ChangeLog
+++ b/gdb/ChangeLog
@@ -1,3 +1,10 @@
+2016-08-24  Simon Marchi  <simon.marchi@ericsson.com>
+
+	* infcmd.c (set_inferior_io_terminal): Set inferior terminal to
+	NULL if terminal_name is an empty string.
+	(_initialize_infcmd): Make the argument of "set inferior-tty"
+	optional, mention it in the help doc.
+
 2016-08-24  Carl Love  <cel@us.ibm.com>
 
 	* rs6000-tdep.c (rs6000_gdbarch_init): Remove call
diff --git a/gdb/doc/ChangeLog b/gdb/doc/ChangeLog
index cc9bc70..c6fe47c 100644
--- a/gdb/doc/ChangeLog
+++ b/gdb/doc/ChangeLog
@@ -1,3 +1,8 @@
+2016-08-24  Simon Marchi  <simon.marchi@ericsson.com>
+
+	* gdb.texinfo (Input/Output): Mention possibility to unset
+	inferior-tty.
+
 2016-07-25  Tim Wiederhake  <tim.wiederhake@intel.com>
 
 	* gdb.texinfo: Resume btrace on reconnect.
diff --git a/gdb/doc/gdb.texinfo b/gdb/doc/gdb.texinfo
index f5dde61..d1a5e7c 100644
--- a/gdb/doc/gdb.texinfo
+++ b/gdb/doc/gdb.texinfo
@@ -2499,9 +2499,11 @@ display the name of the terminal that will be used for future runs of your
 program.
 
 @table @code
-@item set inferior-tty /dev/ttyb
+@item set inferior-tty [ @var{tty} ]
 @kindex set inferior-tty
-Set the tty for the program being debugged to /dev/ttyb.
+Set the tty for the program being debugged to @var{tty}.  Omitting @var{tty}
+restores the default behavior, which is to use the same terminal as
+@value{GDBN}.
 
 @item show inferior-tty
 @kindex show inferior-tty
diff --git a/gdb/infcmd.c b/gdb/infcmd.c
index 58ba1cb..44a1fd1 100644
--- a/gdb/infcmd.c
+++ b/gdb/infcmd.c
@@ -151,7 +151,11 @@ void
 set_inferior_io_terminal (const char *terminal_name)
 {
   xfree (current_inferior ()->terminal);
-  current_inferior ()->terminal = terminal_name ? xstrdup (terminal_name) : 0;
+
+  if (terminal_name != NULL && *terminal_name != '\0')
+    current_inferior ()->terminal = xstrdup (terminal_name);
+  else
+    current_inferior ()->terminal = NULL;
 }
 
 const char *
@@ -3224,14 +3228,16 @@ _initialize_infcmd (void)
   const char *cmd_name;
 
   /* Add the filename of the terminal connected to inferior I/O.  */
-  add_setshow_filename_cmd ("inferior-tty", class_run,
-			    &inferior_io_terminal_scratch, _("\
+  add_setshow_optional_filename_cmd ("inferior-tty", class_run,
+				     &inferior_io_terminal_scratch, _("\
 Set terminal for future runs of program being debugged."), _("\
 Show terminal for future runs of program being debugged."), _("\
-Usage: set inferior-tty /dev/pts/1"),
-			    set_inferior_tty_command,
-			    show_inferior_tty_command,
-			    &setlist, &showlist);
+Usage: set inferior-tty [TTY]\n\n\
+If TTY is omitted, the default behavior of using the same terminal as GDB\n\
+is restored."),
+				     set_inferior_tty_command,
+				     show_inferior_tty_command,
+				     &setlist, &showlist);
   add_com_alias ("tty", "set inferior-tty", class_alias, 0);
 
   cmd_name = "args";
diff --git a/gdb/testsuite/ChangeLog b/gdb/testsuite/ChangeLog
index 26ce978..f400a7b 100644
--- a/gdb/testsuite/ChangeLog
+++ b/gdb/testsuite/ChangeLog
@@ -1,3 +1,8 @@
+2016-08-24  Simon Marchi  <simon.marchi@ericsson.com>
+
+	* gdb.base/set-inferior-tty.exp: New file.
+	* gdb.base/set-inferior-tty.c: New file.
+
 2016-08-23  Pedro Alves  <palves@redhat.com>
 
 	PR gdb/20494
diff --git a/gdb/testsuite/gdb.base/set-inferior-tty.c b/gdb/testsuite/gdb.base/set-inferior-tty.c
new file mode 100644
index 0000000..863fa99
--- /dev/null
+++ b/gdb/testsuite/gdb.base/set-inferior-tty.c
@@ -0,0 +1,24 @@
+/* This testcase is part of GDB, the GNU debugger.
+
+   Copyright 2016 Free Software Foundation, Inc.
+
+   This program is free software; you can redistribute it and/or modify
+   it under the terms of the GNU General Public License as published by
+   the Free Software Foundation; either version 3 of the License, or
+   (at your option) any later version.
+
+   This program is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+   GNU General Public License for more details.
+
+   You should have received a copy of the GNU General Public License
+   along with this program.  If not, see <http://www.gnu.org/licenses/>.
+
+*/
+
+int
+main (void)
+{
+  return 0;
+}
diff --git a/gdb/testsuite/gdb.base/set-inferior-tty.exp b/gdb/testsuite/gdb.base/set-inferior-tty.exp
new file mode 100644
index 0000000..1a5f49c
--- /dev/null
+++ b/gdb/testsuite/gdb.base/set-inferior-tty.exp
@@ -0,0 +1,40 @@
+# Copyright 2016 Free Software Foundation, Inc.
+
+# This program is free software; you can redistribute it and/or modify
+# it under the terms of the GNU General Public License as published by
+# the Free Software Foundation; either version 3 of the License, or
+# (at your option) any later version.
+#
+# This program is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+# GNU General Public License for more details.
+#
+# You should have received a copy of the GNU General Public License
+# along with this program.  If not, see <http://www.gnu.org/licenses/>.
+
+standard_testfile
+
+set compile_options "debug"
+if {[build_executable $testfile.exp $testfile ${srcfile} ${compile_options}] == -1} {
+    untested "failed to compile $testfile"
+    return -1
+}
+
+proc test_set_inferior_tty { } {
+    global binfile
+
+    clean_restart ${binfile}
+
+    gdb_test_no_output "set inferior-tty hello" "set inferior-tty to hello"
+    gdb_test "show inferior-tty" \
+	     "Terminal for future runs of program being debugged is \"hello\"." \
+	     "show inferior-tty shows hello"
+
+    gdb_test_no_output "set inferior-tty" "set inferior-tty to empty"
+    gdb_test "show inferior-tty" \
+	     "Terminal for future runs of program being debugged is \"\"." \
+	     "show inferior-tty shows empty"
+}
+
+test_set_inferior_tty