rather than relying on literal PIDs, break look if no more children

This is more elegant as PIDs get reused.

1 files changed, 11 insertions, 7 deletions

diff --git a/perl5/Local/Interactive.pm b/perl5/Local/Interactive.pm
index fa66d18e..631e4c6a 100644
--- a/perl5/Local/Interactive.pm
+++ b/perl5/Local/Interactive.pm
@@ -216,11 +216,7 @@ sub _sysptycap_tty {
     }
     $pty->close;
     my $output;
-    # don't continue trying to read if child has died.  This is needed
-    # as the child might die without the pty getting EOF, e.g. if an
-    # SSH control socket is still alive (seems to happen when using
-    # Debian's SSH jump host to SSH to salsa)
-    while (kill 0, $pid) {
+    while (1) {
         my $rin = "";
         vec($rin, fileno $slave, 1) = 1;
         if (select $rin, undef, undef, 1) {
@@ -229,8 +225,16 @@ sub _sysptycap_tty {
             print $chars;
             $output .= $chars;
         } else {
-            # since there was no new output, see if child needs reaping
-            waitpid -1, &WNOHANG;
+            # Since there was no new output, see if child needs
+            # reaping, and end the loop if all children have died.
+            # This is needed as the child might die without the pty
+            # getting EOF, e.g. if an SSH control socket is still
+            # alive (seems to happen when using Debian's SSH jump host
+            # to SSH to salsa).
+            #
+            # An alternative is to make the whole loop 'while (kill 0,
+            # $pid)' but this is more elegant as PIDs get reused
+            last if waitpid(-1, WNOHANG) == -1;
         }
     }
     $slave->close;