Add a pause mechanism for debugging tests.

src/tests/e2e-test-server

@@ -5,6 +5,29 @@
 # then captures screen with `tmux capture-pane`.  Captures exitstatus
 # of both and returns appropriate errors.
 #
+
+# If MOSH_E2E_WAIT is set, then the test will wait for another tmux
+# client to attach to the test session before starting, and will wait
+# for other tmux clients to detach before exiting.
+wait_for_clients()
+{
+    if [ -z "$MOSH_E2E_WAIT" ]; then
+	return
+    fi
+    expected=$1
+    while true; do 
+	n=$(tmux list-clients -F . | wc -l)
+	if [ $expected -eq 1 ]; then
+	    if [ $n -eq 1 ]; then
+		return
+	    fi
+	elif [ $n -ne 1 ]; then
+	    return
+	fi
+	sleep 1
+    done
+}
+
 export MOSH_SERVER_PID=$PPID
 
 if [ $# -lt 2 ]; then
@@ -26,6 +49,7 @@ if [ -z "$TMUX_PANE" ]; then
     printf "not running under tmux\n" >&2
     exit 99
 fi
+wait_for_clients 2
 # run harnessed command
 eval "$@"
 testret=$?
@@ -37,6 +61,7 @@ fi
 # Wait for tmux client screen to become up to date.
 sleep 1
 printf "@@@ server complete @@@" >&2
+wait_for_clients 1
 i=0
 while [ $i -lt 60 ]; do
     if grep -q "@@@ server complete @@@" "$testname.tmux.log"; then