3 files changed, 3 insertions, 27 deletions

diff --git a/src/ChangeLog b/src/ChangeLog
index eb28180b7c3..de97c08c6fc 100644
--- a/src/ChangeLog
+++ b/src/ChangeLog
@@ -24,6 +24,9 @@
 
 2012-07-11  Glenn Morris  <rgm@gnu.org>
 
+        * s/bsd-common.h, s/cygwin.h: No need to undefine INTERRUPT_INPUT,
+        since nothing has defined it on these platforms.
+
         * s/aix4-2.h, s/bsd-common.h, s/cygwin.h, s/gnu-linux.h:
         * s/irix6-5.h: Move SIGNALS_VIA_CHARACTERS to configure.
 
diff --git a/src/s/bsd-common.h b/src/s/bsd-common.h
index 184ba7d036b..2e25ff63486 100644
--- a/src/s/bsd-common.h
+++ b/src/s/bsd-common.h
@@ -47,10 +47,6 @@ along with GNU Emacs.  If not, see <http://www.gnu.org/licenses/>.  */
    for X functions taking float or double parameters.  */
 #define NARROWPROTO 1
 
-/* Do not use interrupt_input = 1 by default, because in 4.3
-   we can make noninterrupt input work properly.  */
-#undef INTERRUPT_INPUT
-
 /* First pty name is /dev/ptyp0.  */
 #define FIRST_PTY_LETTER 'p'
 
diff --git a/src/s/cygwin.h b/src/s/cygwin.h
index cf418135b8d..282f9523223 100644
--- a/src/s/cygwin.h
+++ b/src/s/cygwin.h
@@ -17,29 +17,6 @@ GNU General Public License for more details.
 You should have received a copy of the GNU General Public License
 along with GNU Emacs.  If not, see <http://www.gnu.org/licenses/>.  */
 
-/* Emacs can read input using SIGIO and buffering characters itself,
-   or using CBREAK mode and making C-g cause SIGINT.
-   The choice is controlled by the variable interrupt_input.
-
-   Define INTERRUPT_INPUT to make interrupt_input = 1 the default (use SIGIO)
-
-   Emacs uses the presence or absence of the SIGIO and BROKEN_SIGIO macros
-   to indicate whether or not signal-driven I/O is possible.  It uses
-   INTERRUPT_INPUT to decide whether to use it by default.
-
-   SIGIO can be used only on systems that implement it (4.2 and 4.3).
-   CBREAK mode has two disadvantages
-     1) At least in 4.2, it is impossible to handle the Meta key properly.
-        I hear that in system V this problem does not exist.
-     2) Control-G causes output to be discarded.
-        I do not know whether this can be fixed in system V.
-
-   Another method of doing input is planned but not implemented.
-   It would have Emacs fork off a separate process
-   to read the input and send it to the true Emacs process
-   through a pipe. */
-#undef INTERRUPT_INPUT
-
 /* Define HAVE_PTYS if the system supports pty devices.  */
 #define HAVE_PTYS
 #define PTY_ITERATION           int i; for (i = 0; i < 1; i++) /* ick */