Merge branch 'master' of https://github.com/sorin-ionescu/prezto into…

… HEAD

* 'master' of https://github.com/sorin-ionescu/prezto:
  [Fix sorin-ionescu#479] Start only one ssh-agent instance
  [Fix sorin-ionescu#477] Add instructions for updating Prezto

README.md

@@ -39,6 +39,13 @@ If you are not able to find certain commands after switching to *Prezto*,
 modify the `PATH` variable in *~/.zshenv* then open a new Zsh terminal
 window or tab.
 
+Updating
+--------
+
+Pull the latest changes and update submodules.
+
+    git pull && git submodule update --init --recursive
+
 Usage
 -----
 

modules/ssh/init.zsh

@@ -21,10 +21,13 @@ _ssh_agent_sock="$TMPDIR/ssh-agent.sock"
 
 # Start ssh-agent if not started.
 if [[ ! -S "$SSH_AUTH_SOCK" ]]; then
-  eval "$(ssh-agent | sed '/^echo /d' | tee "$_ssh_agent_env")"
-else
   # Export environment variables.
   source "$_ssh_agent_env" 2> /dev/null
+
+  # Start ssh-agent if not started.
+  if ! ps -U "$USER" -o pid,ucomm | grep -q "${SSH_AGENT_PID} ssh-agent"; then
+    eval "$(ssh-agent | sed '/^echo /d' | tee "$_ssh_agent_env")"
+  fi
 fi
 
 # Create a persistent SSH authentication socket.