Unset attach_flag when running a new process

We currently set attach_flag when attaching to a process, so we should
make sure to unset it when forking a new process.  Otherwise attach_flag
would remain set after forking, if the previous process associated with
the inferior was attached to.

gdb/ChangeLog:

	* target.c (target_pre_inferior): Unset attach_flag.

gdb/testsuite/ChangeLog:

	* gdb.base/run-after-attach.exp: New test file.
	* gdb.base/run-after-attach.c: New test file.

1 files changed, 25 insertions, 0 deletions

diff --git a/gdb/testsuite/gdb.base/run-after-attach.c b/gdb/testsuite/gdb.base/run-after-attach.c
new file mode 100644
index 0000000..2398f00
--- /dev/null
+++ b/gdb/testsuite/gdb.base/run-after-attach.c
@@ -0,0 +1,25 @@
+/* This testcase is part of GDB, the GNU debugger.
+
+   Copyright 2015 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 (600);
+  return 0;
+}