From fb641881c2cc82c71a24d63bdbb8fa032340d0e4 Mon Sep 17 00:00:00 2001
From: Bruno Sutic <bruno.sutic@gmail.com>
Date: Fri, 20 Feb 2015 02:05:58 +0100
Subject: [PATCH] Don't start auto-saving if another tmux server is running

---
 CHANGELOG.md                      |  2 ++
 resurrect_auto.tmux               | 20 +++++++++++++++++---
 scripts/helpers.sh                | 30 ++++++++++++++++++++++++++++++
 scripts/resurrect_auto_restore.sh | 31 +++----------------------------
 4 files changed, 52 insertions(+), 31 deletions(-)

diff --git a/CHANGELOG.md b/CHANGELOG.md
index f7161ba..c2c786b 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -6,6 +6,8 @@
 - bugfixes for 'tmux auto start' OS X Terminal.app and iTerm scripts
 - prevent saving for the first 15 minutes only when plugin is sourced the first
   time (not on subsequent sources or tmux.conf reloads)
+- do not start auto-saving if there's another tmux server running (we don't want
+  for save files from various tmux environments to override each other)
 
 ### v2.1.0, 2015-02-18
 - enable "tmux auto start" for OS X
diff --git a/resurrect_auto.tmux b/resurrect_auto.tmux
index 514ea3c..1535bff 100755
--- a/resurrect_auto.tmux
+++ b/resurrect_auto.tmux
@@ -16,6 +16,15 @@ handle_tmux_automatic_start() {
 	$CURRENT_DIR/scripts/handle_tmux_automatic_start.sh
 }
 
+another_tmux_server_running() {
+	if just_started_tmux_server; then
+		another_tmux_server_running_on_startup
+	else
+		# script loaded after tmux server start can have multiple clients attached
+		[ "$(number_tmux_processes_except_current_server)" -gt "$(number_current_server_client_processes)" ]
+	fi
+}
+
 delay_saving_environment_on_first_plugin_load() {
 	if [ -z "$(get_tmux_option "$last_auto_save_option" "")" ]; then
 		# last save option not set, this is first time plugin load
@@ -44,9 +53,14 @@ main() {
 	if supported_tmux_version_ok; then
 		handle_tmux_automatic_start
 
-		# give user a chance to restore previously saved session
-		delay_saving_environment_on_first_plugin_load
-		add_resurrect_save_interpolation
+		# Advanced edge case handling: start auto-saving only if this is the
+		# only tmux server. We don't want saved files from more environments to
+		# overwrite each other.
+		if ! another_tmux_server_running; then
+			# give user a chance to restore previously saved session
+			delay_saving_environment_on_first_plugin_load
+			add_resurrect_save_interpolation
+		fi
 
 		if just_started_tmux_server; then
 			start_auto_restore_in_background
diff --git a/scripts/helpers.sh b/scripts/helpers.sh
index 206eac1..97c0e4f 100644
--- a/scripts/helpers.sh
+++ b/scripts/helpers.sh
@@ -14,3 +14,33 @@ set_tmux_option() {
 	local value="$2"
 	tmux set-option -gq "$option" "$value"
 }
+
+# multiple tmux server detection helpers
+
+current_tmux_server_pid() {
+	echo "$TMUX" |
+		cut -f2 -d","
+}
+
+all_tmux_processes() {
+	ps -Ao "command pid" |
+		\grep "^tmux"
+}
+
+number_tmux_processes_except_current_server() {
+	all_tmux_processes |
+		\grep -v " $(current_tmux_server_pid)$" |
+		wc -l |
+		sed "s/ //g"
+}
+
+number_current_server_client_processes() {
+	tmux list-clients |
+		wc -l |
+		sed "s/ //g"
+}
+
+another_tmux_server_running_on_startup() {
+	# there are 2 tmux processes (current tmux server + 1) on tmux startup
+	[ "$(number_tmux_processes_except_current_server)" -gt 1 ]
+}
diff --git a/scripts/resurrect_auto_restore.sh b/scripts/resurrect_auto_restore.sh
index 65eba23..27afbc4 100755
--- a/scripts/resurrect_auto_restore.sh
+++ b/scripts/resurrect_auto_restore.sh
@@ -10,33 +10,6 @@ auto_restore_enabled() {
 	[ "$auto_restore_value" == "on" ] && [ ! -f "$auto_restore_halt_file" ]
 }
 
-current_tmux_server_pid() {
-	echo "$TMUX" |
-		cut -f2 -d","
-}
-
-all_tmux_processes() {
-	ps -Ao "command pid" |
-		\grep "^tmux"
-}
-
-tmux_processes_except_current_server() {
-	all_tmux_processes |
-		\grep -v " $(current_tmux_server_pid)$"
-}
-
-number_tmux_processes_except_current_server() {
-	all_tmux_processes |
-		\grep -v " $(current_tmux_server_pid)$" |
-		wc -l |
-		sed "s/ //g"
-}
-
-another_tmux_server_running() {
-	# there are 2 tmux processes (current tmux server + 1) on tmux startup
-	[ "$(number_tmux_processes_except_current_server)" -gt 1 ]
-}
-
 fetch_and_run_tmux_resurrect_restore_script() {
 	# give tmux some time to start and source all the plugins
 	sleep 1
@@ -47,7 +20,9 @@ fetch_and_run_tmux_resurrect_restore_script() {
 }
 
 main() {
-	if auto_restore_enabled && ! another_tmux_server_running; then
+	# Advanced edge case handling: auto restore only if this is the only tmux
+	# server. If another tmux server exists, it is assumed auto-restore is not wanted.
+	if auto_restore_enabled && ! another_tmux_server_running_on_startup; then
 		fetch_and_run_tmux_resurrect_restore_script
 	fi
 }