diff --git a/gdb/infcmd.c b/gdb/infcmd.c
index 0374533..d270664 100644
--- a/gdb/infcmd.c
+++ b/gdb/infcmd.c
@@ -735,6 +735,24 @@ continue_1 (int all_threads)
 
       iterate_over_threads (proceed_thread_callback, NULL);
 
+      if (sync_execution)
+	{
+	  /* If all threads in the target were already running,
+	     proceed_thread_callback ends up never calling proceed,
+	     and so nothing calls this to put the inferior's terminal
+	     settings in effect and remove stdin from the event loop,
+	     which we must when running a foreground command.  E.g.:
+
+	      (gdb) c -a&
+	      Continuing.
+	      <all threads are running now>
+	      (gdb) c -a
+	      Continuing.
+	      <no thread was resumed, but the inferior now owns the terminal>
+	  */
+	  target_terminal_inferior ();
+	}
+
       /* Restore selected ptid.  */
       do_cleanups (old_chain);
     }
diff --git a/gdb/testsuite/gdb.base/continue-all-already-running.c b/gdb/testsuite/gdb.base/continue-all-already-running.c
new file mode 100644
index 0000000..a6516d5
--- /dev/null
+++ b/gdb/testsuite/gdb.base/continue-all-already-running.c
@@ -0,0 +1,25 @@
+/* This testcase is part of GDB, the GNU debugger.
+
+   Copyright 2014 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/>.  */
+
+#include <unistd.h>
+
+int
+main (void)
+{
+  sleep (10);
+  return 0; /* set break here */
+}
diff --git a/gdb/testsuite/gdb.base/continue-all-already-running.exp b/gdb/testsuite/gdb.base/continue-all-already-running.exp
new file mode 100644
index 0000000..6dde730
--- /dev/null
+++ b/gdb/testsuite/gdb.base/continue-all-already-running.exp
@@ -0,0 +1,79 @@
+# Copyright (C) 2014 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/>.
+
+# Test that "c -a" doesn't leave GDB processing input, even if all
+# threads were already running.  PR gdb/17300.
+
+standard_testfile
+
+if { [prepare_for_testing ${testfile}.exp ${testfile} $srcfile] } {
+    return -1
+}
+
+gdb_test_no_output "set non-stop on"
+
+if ![runto_main] {
+    return
+}
+
+set linenum [gdb_get_line_number "set break here"]
+gdb_breakpoint "$linenum"
+
+gdb_test "c -a&" "Continuing\\."
+
+set test "no stop"
+gdb_test_multiple "" $test {
+    -timeout 1
+    timeout {
+	pass $test
+    }
+}
+
+# Paranoia.  Check that input works after bg command.
+gdb_test "print 1" " = 1"
+
+# Continue in the foreground, and wait one second to make sure the
+# inferior really starts running.  If we get a prompt to soon (e.g.,
+# the program stops), this issues a fail.
+set saw_continuing 0
+set test "c -a"
+gdb_test_multiple "c -a" $test {
+    -timeout 1
+    -re "Continuing\\." {
+	set saw_continuing 1
+	exp_continue
+    }
+    timeout {
+	gdb_assert $saw_continuing $test
+    }
+}
+
+# Type something while the inferior is running in the foreground.
+send_gdb "print 2\n"
+
+# Poor buggy GDB would crash before the breakpoint was hit.
+set test "breakpoint hit"
+gdb_test_multiple "" $test {
+    -re "set break here ..\r\n$gdb_prompt " {
+	pass $test
+    }
+}
+
+set test "print command result"
+gdb_test_multiple "" $test {
+    -re " = 2\r\n$gdb_prompt $" {
+	pass $test
+    }
+}
