* configure.in (BROKEN_SA_RESTART): Doc fix.

* src/sysdep.c, src/s/irix6-5.h: Related comments.

4 files changed, 12 insertions, 7 deletions

diff --git a/ChangeLog b/ChangeLog
index 1b7fa14edd3..f488b7f3aee 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,5 +1,7 @@
 2012-07-07  Glenn Morris  <rgm@gnu.org>
 
+        * configure.in (BROKEN_SA_RESTART): Doc fix.
+
         * configure.in: Rather than checking for things then undef'ing
         them on some platforms, simply don't check for them.
         (getwd): Don't check for it on unixware.
diff --git a/configure.in b/configure.in
index fdd7ea0156c..59a7130ed49 100644
--- a/configure.in
+++ b/configure.in
@@ -3140,9 +3140,11 @@ case $opsys in
    gnu-kfreebsd) opsysfile="s/gnu-linux.h" ;;
 
    hpux11)
-     dnl SA_RESTART resets the timeout of `select', so don't use it.
-     AC_DEFINE(BROKEN_SA_RESTART, 1, [Define if SA_RESTART should not
-       be used.])
+     dnl See comments in sysdep.c:sys_signal.
+     dnl SA_RESTART resets the timeout of `select' on hpux11.
+     dnl Defining BROKEN_SA_RESTART is not the same as undef'ing SA_RESTART.
+     AC_DEFINE(BROKEN_SA_RESTART, 1, [Define if SA_RESTART should only
+       be used in batch mode.])
      dnl It works to open the pty's tty in the parent (Emacs), then
      dnl close and reopen it in the child.
      AC_DEFINE(USG_SUBTTY_WORKS, 1, [Define for USG systems where it
diff --git a/src/s/irix6-5.h b/src/s/irix6-5.h
index 7e5a5505ee2..30aca2b5416 100644
--- a/src/s/irix6-5.h
+++ b/src/s/irix6-5.h
@@ -80,7 +80,7 @@ char *_getpty();
 
 #define NARROWPROTO 1
 
-#undef SA_RESTART
+#undef SA_RESTART     /* not the same as defining BROKEN_SA_RESTART */
 
 #undef TIOCSIGSEND              /* defined in usg5-4-common.h */
 
diff --git a/src/sysdep.c b/src/sysdep.c
index 475c977044b..0639b72285a 100644
--- a/src/sysdep.c
+++ b/src/sysdep.c
@@ -1484,9 +1484,10 @@ sys_signal (int signal_number, signal_handler_t action)
 #if defined (SA_RESTART)
   /* Emacs mostly works better with restartable system services. If this
      flag exists, we probably want to turn it on here.
-     However, on some systems this resets the timeout of `select'
-     which means that `select' never finishes if it keeps getting signals.
-     BROKEN_SA_RESTART is defined on those systems.  */
+     However, on some systems (only hpux11 at present) this resets the
+     timeout of `select' which means that `select' never finishes if
+     it keeps getting signals.
+     We define BROKEN_SA_RESTART on those systems.  */
   /* It's not clear why the comment above says "mostly works better".  --Stef
      When SYNC_INPUT is set, we don't want SA_RESTART because we need to poll
      for pending input so we need long-running syscalls to be interrupted