problem sourcing GDB script in interactive-mode on

When interactive-mode is not auto, GDB always uses that setting to
determine whether to act as if the input stream is a terminal or not.
However, this setting should only be honored if the input stream is
the standard input stream.  Otherwise, we run into trouble while
source-ing a GDB script, as shown below (on x86_64-linux):

        % cat script
        print 1
        print 2
        % gdb  -q
        (gdb) set interactive-mode on
        (gdb) source script
        (gdb) print 3
        $1 = 3

The lack of output and the fact that the "print 3" command returned
a value saved in $1 (as opposed to $3) indicates that the script was
not even evaluated at all.

gdb/ChangeLog:

        * top.c (input_from_terminal_p): Restrict the use of interactive_mode
        to the case where instream is stdin.

gdb/testsuite/ChangeLog:

        * gdb.base/interact.exp: New testcase.

gdb/ChangeLog

@@ -1,3 +1,8 @@
+2011-01-13  Joel Brobecker  <brobecker@adacore.com>
+
+	* top.c (input_from_terminal_p): Restrict the use of interactive_mode
+	to the case where instream is stdin.
+
 2011-01-13  Joel Brobecker  <brobecker@adacore.com>
 
 	* ia64-tdep.h (struct regcache): Forward declare.

gdb/testsuite/ChangeLog

@@ -1,3 +1,7 @@
+2011-01-13  Joel Brobecker  <brobecker@adacore.com>
+
+	* gdb.base/interact.exp: New testcase.
+
 2011-01-12  Tom Tromey  <tromey@redhat.com>
 
 	* gdb.mi/gdb2549.exp: Update for error message changes.

gdb/testsuite/gdb.base/interact.exp

@@ -0,0 +1,48 @@
+# Copyright 2011 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/>.
+
+# Create a GDB script that we can source.  The script needs to generate
+# some output, to allow us to verify that it is executed properly.
+set fd [open "zzz-gdbscript" "w"]
+puts $fd "print 1"
+puts $fd "print 2"
+close $fd
+
+# The expected output from the script...
+set script_output "\\$\[0-9\]+ = 1\[\r\n\]+\\$\[0-9\]+ = 2.*"
+
+# Start a fresh GDB.  We don't need an executable for this test, so
+# nothing else to do in terms of testcase setup.
+gdb_exit
+gdb_start
+
+# Test sourcing of the script with interactive mode `auto'
+gdb_test_no_output "set interactive-mode auto"
+gdb_test "source zzz-gdbscript" "$script_output" \
+         "source script with interactive-mode auto"
+gdb_test "print 3" "= 3" "sanity check with interactive-mode auto"
+
+# Test sourcing of the script with interactive mode `on'
+gdb_test_no_output "set interactive-mode on"
+gdb_test "source zzz-gdbscript" "$script_output" \
+         "source script with interactive-mode on"
+gdb_test "print 4" "= 4" "sanity check with interactive-mode on"
+
+# Test sourcing of the script with interactive mode `of'
+gdb_test_no_output "set interactive-mode off"
+gdb_test "source zzz-gdbscript" "$script_output" \
+         "source script with interactive-mode off"
+gdb_test "print 5" "= 5" "sanity check with interactive-mode off"
+

gdb/top.c

@@ -1292,7 +1292,7 @@ show_interactive_mode (struct ui_file *file, int from_tty,
 int
 input_from_terminal_p (void)
 {
-  if (interactive_mode != AUTO_BOOLEAN_AUTO)
+  if (interactive_mode != AUTO_BOOLEAN_AUTO && instream == stdin)
     return interactive_mode == AUTO_BOOLEAN_TRUE;
 
   if (batch_flag)