Merge remote-tracking branch 'source/master'

2017-02-07 13:58:54 +01:00
parent 70b7a67057 fcd942622d
commit 72435323d0
6 changed files with 450 additions and 178 deletions
--- a/.github/issue_template.md
+++ b/.github/issue_template.md
@@ -0,0 +1,34 @@
+<!-- TIP: Hit 'Preview' for a more readable version of this template --> 
+
+### General information
+
+- Pure version: 1.x.x
+- ZSH version: 5.x.x
+- Terminal program & version: <!-- e.g. Hyper 1.0.0, iTerm 3.0.0, Terminal 2.7.1, xterm 327, other? -->
+- Operating system: <!-- e.g. macOS Sierra 10.12.1 -->
+- ZSH framework: <!-- e.g. oh-my-zsh, prezto, antigen, antibody, zplug, other? -->
+
+I have:
+- [ ] Tested with another terminal program and can reproduce the issue: <!-- e.g. iTerm, etc. -->
+- [ ] Followed the [Integration](https://github.com/sindresorhus/pure#integration) instructions for my framework
+
+### Problem description
+
+
+### Reproduction steps
+
+1.
+2.
+3.
+
+### My `.zshrc`:
+
+<!--
+Please provide a minimal `.zshrc` that reproduces the issue.
+Try to remove everything that that does not affect the issue, the fewer lines, the better.
+-->
+
+```shell
+autoload -U promptinit; promptinit
+prompt pure
+```
--- a/async.zsh
+++ b/async.zsh
@@ -3,96 +3,160 @@
 #
 # zsh-async
 #
-# version: 1.1.0
+# version: 1.5.0
 # author: Mathias Fredriksson
 # url: https://github.com/mafredri/zsh-async
 #

+# Produce debug output from zsh-async when set to 1.
+ASYNC_DEBUG=${ASYNC_DEBUG:-0}
+
 # Wrapper for jobs executed by the async worker, gives output in parseable format with execution time
 _async_job() {
+	# Disable xtrace as it would mangle the output.
+	setopt localoptions noxtrace
+
 	# Store start time as double precision (+E disables scientific notation)
 	float -F duration=$EPOCHREALTIME

-	# Run the command
-	#
-	# What is happening here is that we are assigning stdout, stderr and ret to
-	# variables, and then we are printing out the variable assignment through
-	# typeset -p. This way when we run eval we get something along the lines of:
-	# 	eval "
-	# 		typeset stdout=' M async.test.sh\n M async.zsh'
-	# 		typeset ret=0
-	# 		typeset stderr=''
-	# 	"
-	unset stdout stderr ret
-	eval "$(
-		{
-			stdout=$(eval "$@")
-			ret=$?
-			typeset -p stdout ret
-		} 2> >(stderr=$(cat); typeset -p stderr)
-	)"
+	# Run the command and capture both stdout (`eval`) and stderr (`cat`) in
+	# separate subshells. When the command is complete, we grab write lock
+	# (mutex token) and output everything except stderr inside the command
+	# block, after the command block has completed, the stdin for `cat` is
+	# closed, causing stderr to be appended with a $'\0' at the end to mark the
+	# end of output from this job.
+	local stdout stderr ret tok
+	{
+		stdout=$(eval "$@")
+		ret=$?
+		duration=$(( EPOCHREALTIME - duration ))  # Calculate duration.

-	# Calculate duration
-	duration=$(( EPOCHREALTIME - duration ))
+		# Grab mutex lock, stalls until token is available.
+		read -r -k 1 -p tok || exit 1

-	# stip all null-characters from stdout and stderr
-	stdout=${stdout//$'\0'/}
-	stderr=${stderr//$'\0'/}
+		# Return output (<job_name> <return_code> <stdout> <duration> <stderr>).
+		print -r -n - ${(q)1} $ret ${(q)stdout} $duration
+	} 2> >(stderr=$(cat) && print -r -n - " "${(q)stderr}$'\0')

-	# if ret is missing for some unknown reason, set it to -1 to indicate we
-	# have run into a bug
-	ret=${ret:--1}
-
-	# Grab mutex lock
-	read -ep >/dev/null
-
-	# return output (<job_name> <return_code> <stdout> <duration> <stderr>)
-	print -r -N -n -- "$1" "$ret" "$stdout" "$duration" "$stderr"$'\0'
-
-	# Unlock mutex
-	print -p "t"
+	# Unlock mutex by inserting a token.
+	print -n -p $tok
 }

 # The background worker manages all tasks and runs them without interfering with other processes
 _async_worker() {
+	# Reset all options to defaults inside async worker.
+	emulate -R zsh
+
+	# Make sure monitor is unset to avoid printing the
+	# pids of child processes.
+	unsetopt monitor
+
+	# Redirect stderr to `/dev/null` in case unforseen errors produced by the
+	# worker. For example: `fork failed: resource temporarily unavailable`.
+	# Some older versions of zsh might also print malloc errors (know to happen
+	# on at least zsh 5.0.2 and 5.0.8) likely due to kill signals.
+	exec 2>/dev/null
+
+	# When a zpty is deleted (using -d) all the zpty instances created before
+	# the one being deleted receive a SIGHUP, unless we catch it, the async
+	# worker would simply exit (stop working) even though visible in the list
+	# of zpty's (zpty -L).
+	TRAPHUP() {
+		return 0  # Return 0, indicating signal was handled.
+	}
+
 	local -A storage
 	local unique=0
+	local notify_parent=0
+	local parent_pid=0
+	local coproc_pid=0
+	local processing=0
+
+	local -a zsh_hooks zsh_hook_functions
+	zsh_hooks=(chpwd periodic precmd preexec zshexit zshaddhistory)
+	zsh_hook_functions=(${^zsh_hooks}_functions)
+	unfunction $zsh_hooks &>/dev/null   # Deactivate all zsh hooks inside the worker.
+	unset $zsh_hook_functions           # And hooks with registered functions.
+	unset zsh_hooks zsh_hook_functions  # Cleanup.
+
+	child_exit() {
+		local -a pids
+		pids=(${${(v)jobstates##*:*:}%\=*})
+
+		# If coproc (cat) is the only child running, we close it to avoid
+		# leaving it running indefinitely and cluttering the process tree.
+		if  (( ! processing )) && [[ $#pids = 1 ]] && [[ $coproc_pid = $pids[1] ]]; then
+			coproc :
+			coproc_pid=0
+		fi
+
+		# On older version of zsh (pre 5.2) we notify the parent through a
+		# SIGWINCH signal because `zpty` did not return a file descriptor (fd)
+		# prior to that.
+		if (( notify_parent )); then
+			# We use SIGWINCH for compatibility with older versions of zsh
+			# (pre 5.1.1) where other signals (INFO, ALRM, USR1, etc.) could
+			# cause a deadlock in the shell under certain circumstances.
+			kill -WINCH $parent_pid
+		fi
+	}
+
+	# Register a SIGCHLD trap to handle the completion of child processes.
+	trap child_exit CHLD

 	# Process option parameters passed to worker
 	while getopts "np:u" opt; do
 		case $opt in
-			# Use SIGWINCH since many others seem to cause zsh to freeze, e.g. ALRM, INFO, etc.
-			n) trap 'kill -WINCH $ASYNC_WORKER_PARENT_PID' CHLD;;
-			p) ASYNC_WORKER_PARENT_PID=$OPTARG;;
+			n) notify_parent=1;;
+			p) parent_pid=$OPTARG;;
 			u) unique=1;;
 		esac
 	done

-	# Create a mutex for writing to the terminal through coproc
-	coproc cat
-	# Insert token into coproc
-	print -p "t"
+	killjobs() {
+		local tok
+		local -a pids
+		pids=(${${(v)jobstates##*:*:}%\=*})

-	while read -r cmd; do
-		# Separate on spaces into an array
-		cmd=(${=cmd})
-		local job=$cmd[1]
+		# No need to send SIGHUP if no jobs are running.
+		(( $#pids == 0 )) && continue
+		(( $#pids == 1 )) && [[ $coproc_pid = $pids[1] ]] && continue
+
+		# Grab lock to prevent half-written output in case a child
+		# process is in the middle of writing to stdin during kill.
+		(( coproc_pid )) && read -r -k 1 -p tok
+
+		kill -HUP -$$  # Send to entire process group.
+		coproc :       # Quit coproc.
+		coproc_pid=0   # Reset pid.
+	}
+
+	local request
+	local -a cmd
+	while :; do
+		# Wait for jobs sent by async_job.
+		read -r -d $'\0' request || {
+			# Since we handle SIGHUP above (and thus do not know when `zpty -d`)
+			# occurs, a failure to read probably indicates that stdin has
+			# closed. This is why we propagate the signal to all children and
+			# exit manually.
+			kill -HUP -$$  # Send SIGHUP to all jobs.
+			exit 0
+		}

 		# Check for non-job commands sent to worker
-		case $job in
-			_unset_trap)
-				trap - CHLD; continue;;
-			_killjobs)
-				# Do nothing in the worker when receiving the TERM signal
-				trap '' TERM
-				# Send TERM to the entire process group (PID and all children)
-				kill -TERM -$$ &>/dev/null
-				# Reset trap
-				trap - TERM
-				continue
-				;;
+		case $request in
+			_unset_trap) notify_parent=0; continue;;
+			_killjobs)   killjobs; continue;;
 		esac

+		# Parse the request using shell parsing (z) to allow commands
+		# to be parsed from single strings and multi-args alike.
+		cmd=("${(z)request}")
+
+		# Name of the job (first argument).
+		local job=$cmd[1]
+
 		# If worker should perform unique jobs
 		if (( unique )); then
 			# Check if a previous job is still running, if yes, let it finnish
@@ -103,10 +167,25 @@ _async_worker() {
 			done
 		fi

-		# Run task in background
+		# Guard against closing coproc from trap before command has started.
+		processing=1
+
+		# Because we close the coproc after the last job has completed, we must
+		# recreate it when there are no other jobs running.
+		if (( ! coproc_pid )); then
+			# Use coproc as a mutex for synchronized output between children.
+			coproc cat
+			coproc_pid="$!"
+			# Insert token into coproc
+			print -n -p "t"
+		fi
+
+		# Run job in background, completed jobs are printed to stdout.
 		_async_job $cmd &
 		# Store pid because zsh job manager is extremely unflexible (show jobname as non-unique '$job')...
-		storage[$job]=$!
+		storage[$job]="$!"
+
+		processing=0  # Disable guard.
 	done
 }

@@ -127,38 +206,55 @@ _async_worker() {
 async_process_results() {
 	setopt localoptions noshwordsplit

-	integer count=0
 	local worker=$1
 	local callback=$2
+	local caller=$3
 	local -a items
-	local IFS=$'\0'
+	local null=$'\0' data
+	integer -l len pos num_processed

 	typeset -gA ASYNC_PROCESS_BUFFER
-	# Read output from zpty and parse it if available
-	while zpty -rt $worker line 2>/dev/null; do
-		# Remove unwanted \r from output
-		ASYNC_PROCESS_BUFFER[$worker]+=${line//$'\r'$'\n'/$'\n'}
-		# Split buffer on null characters, preserve empty elements
-		items=("${(@)=ASYNC_PROCESS_BUFFER[$worker]}")
-		# Remove last element since it's due to the return string separator structure
-		items=("${(@)items[1,${#items}-1]}")

-		# Continue until we receive all information
-		(( ${#items} % 5 )) && continue
+	# Read output from zpty and parse it if available.
+	while zpty -r -t $worker data 2>/dev/null; do
+		ASYNC_PROCESS_BUFFER[$worker]+=$data
+		len=${#ASYNC_PROCESS_BUFFER[$worker]}
+		pos=${ASYNC_PROCESS_BUFFER[$worker][(i)$null]}  # Get index of NULL-character (delimiter).

-		# Work through all results
-		while (( ${#items} > 0 )); do
-			$callback "${(@)=items[1,5]}"
-			shift 5 items
-			count+=1
+		# Keep going until we find a NULL-character.
+		if (( ! len )) || (( pos > len )); then
+			continue
+		fi
+
+		while (( pos <= len )); do
+			# Take the content from the beginning, until the NULL-character and
+			# perform shell parsing (z) and unquoting (Q) as an array (@).
+			items=("${(@Q)${(z)ASYNC_PROCESS_BUFFER[$worker][1,$pos-1]}}")
+
+			# Remove the extracted items from the buffer.
+			ASYNC_PROCESS_BUFFER[$worker]=${ASYNC_PROCESS_BUFFER[$worker][$pos+1,$len]}
+
+			if (( $#items == 5 )); then
+				$callback "${(@)items}"  # Send all parsed items to the callback.
+			else
+				# In case of corrupt data, invoke callback with *async* as job
+				# name, non-zero exit status and an error message on stderr.
+				$callback "async" 1 "" 0 "$0:$LINENO: error: bad format, got ${#items} items (${(@q)items})"
+			fi
+
+			(( num_processed++ ))
+
+			len=${#ASYNC_PROCESS_BUFFER[$worker]}
+			if (( len > 1 )); then
+				pos=${ASYNC_PROCESS_BUFFER[$worker][(i)$null]}  # Get index of NULL-character (delimiter).
+			fi
 		done
-
-		# Empty the buffer
-		unset "ASYNC_PROCESS_BUFFER[$worker]"
 	done

-	# If we processed any results, return success
-	(( count )) && return 0
+	(( num_processed )) && return 0
+
+	# Avoid printing exit value when `setopt printexitvalue` is active.`
+	[[ $caller = trap || $caller = watcher ]] && return 0

 	# No results were processed
 	return 1
@@ -172,7 +268,7 @@ _async_zle_watcher() {
 	local callback=$ASYNC_CALLBACKS[$worker]

 	if [[ -n $callback ]]; then
-		async_process_results $worker $callback
+		async_process_results $worker $callback watcher
 	fi
 }

@@ -186,7 +282,14 @@ async_job() {
 	setopt localoptions noshwordsplit

 	local worker=$1; shift
-	zpty -w $worker $@
+
+	local -a cmd
+	cmd=("$@")
+	if (( $#cmd > 1 )); then
+		cmd=(${(q)cmd})  # Quote special characters in multi argument commands.
+	fi
+
+	zpty -w $worker $cmd$'\0'
 }

 # This function traps notification signals and calls all registered callbacks
@@ -194,7 +297,7 @@ _async_notify_trap() {
 	setopt localoptions noshwordsplit

 	for k in ${(k)ASYNC_CALLBACKS}; do
-		async_process_results $k ${ASYNC_CALLBACKS[$k]}
+		async_process_results $k ${ASYNC_CALLBACKS[$k]} trap
 	done
 }

@@ -213,7 +316,9 @@ async_register_callback() {

 	ASYNC_CALLBACKS[$worker]="$*"

-	if (( ! ASYNC_USE_ZLE_HANDLER )); then
+	# Enable trap when the ZLE watcher is unavailable, allows
+	# workers to notify (via -n) when a job is done.
+	if [[ ! -o interactive ]] || [[ ! -o zle ]]; then
 		trap '_async_notify_trap' WINCH
 	fi
 }
@@ -246,12 +351,19 @@ async_flush_jobs() {
 	zpty -t $worker &>/dev/null || return 1

 	# Send kill command to worker
-	zpty -w $worker "_killjobs"
+	async_job $worker "_killjobs"

-	# Clear all output buffers
-	while zpty -r $worker line; do true; done
+	# Clear the zpty buffer.
+	local junk
+	if zpty -r -t $worker junk '*'; then
+		(( ASYNC_DEBUG )) && print -n "async_flush_jobs $worker: ${(V)junk}"
+		while zpty -r -t $worker junk '*'; do
+			(( ASYNC_DEBUG )) && print -n "${(V)junk}"
+		done
+		(( ASYNC_DEBUG )) && print
+	fi

-	# Clear any partial buffers
+	# Finally, clear the process buffer in case of partially parsed responses.
 	typeset -gA ASYNC_PROCESS_BUFFER
 	unset "ASYNC_PROCESS_BUFFER[$worker]"
 }
@@ -276,16 +388,47 @@ async_start_worker() {

 	typeset -gA ASYNC_PTYS
 	typeset -h REPLY
+	typeset has_xtrace=0
+
+	# Make sure async worker is started without xtrace
+	# (the trace output interferes with the worker).
+	[[ -o xtrace ]] && {
+		has_xtrace=1
+		unsetopt xtrace
+	}
+
+	if (( ! ASYNC_ZPTY_RETURNS_FD )) && [[ -o interactive ]] && [[ -o zle ]]; then
+		# When zpty doesn't return a file descriptor (on older versions of zsh)
+		# we try to guess it anyway.
+		integer -l zptyfd
+		exec {zptyfd}>&1  # Open a new file descriptor (above 10).
+		exec {zptyfd}>&-  # Close it so it's free to be used by zpty.
+	fi
+
 	zpty -b $worker _async_worker -p $$ $@ || {
 		async_stop_worker $worker
 		return 1
 	}

-	if (( ASYNC_USE_ZLE_HANDLER )); then
-		ASYNC_PTYS[$REPLY]=$worker
-		zle -F $REPLY _async_zle_watcher
+	# Re-enable it if it was enabled, for debugging.
+	(( has_xtrace )) && setopt xtrace

-		# If worker was called with -n, disable trap in favor of zle handler
+	if [[ $ZSH_VERSION < 5.0.8 ]]; then
+		# For ZSH versions older than 5.0.8 we delay a bit to give
+		# time for the worker to start before issuing commands,
+		# otherwise it will not be ready to receive them.
+		sleep 0.001
+	fi
+
+	if [[ -o interactive ]] && [[ -o zle ]]; then
+		if (( ! ASYNC_ZPTY_RETURNS_FD )); then
+			REPLY=$zptyfd  # Use the guessed value for the file desciptor.
+		fi
+
+		ASYNC_PTYS[$REPLY]=$worker        # Map the file desciptor to the worker.
+		zle -F $REPLY _async_zle_watcher  # Register the ZLE handler.
+
+		# Disable trap in favor of ZLE handler when notify is enabled (-n).
 		async_job $worker _unset_trap
 	fi
 }
@@ -310,6 +453,10 @@ async_stop_worker() {
 		done
 		async_unregister_callback $worker
 		zpty -d $worker 2>/dev/null || ret=$?
+
+		# Clear any partial buffers.
+		typeset -gA ASYNC_PROCESS_BUFFER
+		unset "ASYNC_PROCESS_BUFFER[$worker]"
 	done

 	return $ret
@@ -328,12 +475,13 @@ async_init() {
 	zmodload zsh/zpty
 	zmodload zsh/datetime

-	# Check if zsh/zpty returns a file descriptor or not, shell must also be interactive
-	ASYNC_USE_ZLE_HANDLER=0
-	[[ -o interactive ]] && {
+	# Check if zsh/zpty returns a file descriptor or not,
+	# shell must also be interactive with zle enabled.
+	ASYNC_ZPTY_RETURNS_FD=0
+	[[ -o interactive ]] && [[ -o zle ]] && {
 		typeset -h REPLY
-		zpty _async_test cat
-		(( REPLY )) && ASYNC_USE_ZLE_HANDLER=1
+		zpty _async_test :
+		(( REPLY )) && ASYNC_ZPTY_RETURNS_FD=1
 		zpty -d _async_test
 	}
 }
--- a/package.json
+++ b/package.json
@@ -1,6 +1,6 @@
 {
  "name": "pure-prompt",
-  "version": "1.3.0",
+  "version": "1.5.0",
  "description": "Pretty, minimal and fast ZSH prompt",
  "license": "MIT",
  "repository": "sindresorhus/pure",
@@ -19,7 +19,7 @@
    "node": ">=0.10.0"
  },
  "scripts": {
-    "postinstall": "dest=/usr/local/share/zsh/site-functions/; mkdir -p $dest && ln -sf \"$PWD/pure.zsh\" $dest/prompt_pure_setup && ln -sf \"$PWD/async.zsh\" $dest/async || echo 'Could not automagically symlink the prompt. Check out the readme on how to do it manually: https://github.com/sindresorhus/pure#manually'"
+    "postinstall": "dest=/usr/local/share/zsh/site-functions; mkdir -p $dest && ln -sf \"$PWD/pure.zsh\" $dest/prompt_pure_setup && ln -sf \"$PWD/async.zsh\" $dest/async || echo 'Could not automagically symlink the prompt. Check out the readme on how to do it manually: https://github.com/sindresorhus/pure#manually'"
  },
  "files": [
    "pure.zsh",
--- a/pure.zsh
+++ b/pure.zsh
@@ -61,30 +61,10 @@ prompt_pure_clear_screen() {
 	prompt_pure_preprompt_render precmd
 }

-prompt_pure_check_git_arrows() {
-	# reset git arrows
-	prompt_pure_git_arrows=
-
-	# check if there is an upstream configured for this branch
-	command git rev-parse --abbrev-ref @'{u}' &>/dev/null || return
-
-	local arrow_status
-	# check git left and right arrow_status
-	arrow_status="$(command git rev-list --left-right --count HEAD...@'{u}' 2>/dev/null)"
-	# exit if the command failed
-	(( !$? )) || return
-
-	# left and right are tab-separated, split on tab and store as array
-	arrow_status=(${(ps:\t:)arrow_status})
-	local arrows left=${arrow_status[1]} right=${arrow_status[2]}
-
-	(( ${right:-0} > 0 )) && arrows+="${PURE_GIT_DOWN_ARROW:-⇣}"
-	(( ${left:-0} > 0 )) && arrows+="${PURE_GIT_UP_ARROW:-⇡}"
-
-	[[ -n $arrows ]] && prompt_pure_git_arrows=" ${arrows}"
-}
-
 prompt_pure_set_title() {
+	# emacs terminal does not support settings the title
+	(( ${+EMACS} )) && return
+
 	# tell the terminal we are setting the title
 	print -n '\e]0;'
 	# show hostname if connected through ssh
@@ -120,6 +100,12 @@ prompt_pure_string_length_to_var() {
 }

 prompt_pure_preprompt_render() {
+	# store the current prompt_subst setting so that it can be restored later
+	local prompt_subst_status=$options[prompt_subst]
+
+	# make sure prompt_subst is unset to prevent parameter expansion in preprompt
+	setopt local_options no_prompt_subst
+
 	# check that no command is currently running, the preprompt will otherwise be rendered in the wrong place
 	[[ -n ${prompt_pure_cmd_timestamp+x} && "$1" != "precmd" ]] && return

@@ -138,12 +124,15 @@ prompt_pure_preprompt_render() {
 	# execution time
 	preprompt+="%F{yellow}${prompt_pure_cmd_exec_time}%f"

+	# make sure prompt_pure_last_preprompt is a global array
+	typeset -g -a prompt_pure_last_preprompt
+
 	# if executing through precmd, do not perform fancy terminal editing
 	if [[ "$1" == "precmd" ]]; then
 		print -P "${preprompt}"
 	else
-		# only redraw if preprompt has changed
-		[[ "${prompt_pure_last_preprompt}" != "${preprompt}" ]] || return
+		# only redraw if the expanded preprompt has changed
+		[[ "${prompt_pure_last_preprompt[2]}" != "${(S%%)preprompt}" ]] || return

 		# calculate length of preprompt and store it locally in preprompt_length
 		integer preprompt_length lines
@@ -154,7 +143,7 @@ prompt_pure_preprompt_render() {

 		# calculate previous preprompt lines to figure out how the new preprompt should behave
 		integer last_preprompt_length last_lines
-		prompt_pure_string_length_to_var "${prompt_pure_last_preprompt}" "last_preprompt_length"
+		prompt_pure_string_length_to_var "${prompt_pure_last_preprompt[1]}" "last_preprompt_length"
 		(( last_lines = ( last_preprompt_length - 1 ) / COLUMNS + 1 ))

 		# clr_prev_preprompt erases visual artifacts from previous preprompt
@@ -174,9 +163,6 @@ prompt_pure_preprompt_render() {
 		elif (( last_lines < lines )); then
 			# move cursor using newlines because ansi cursor movement can't push the cursor beyond the last line
 			printf $'\n'%.0s {1..$(( lines - last_lines ))}
-
-			# redraw the prompt since it has been moved by print
-			zle && zle .reset-prompt
 		fi

 		# disable clearing of line if last char of preprompt is last column of terminal
@@ -184,11 +170,19 @@ prompt_pure_preprompt_render() {
 		(( COLUMNS * lines == preprompt_length )) && clr=

 		# modify previous preprompt
-		print -Pn "\e7${clr_prev_preprompt}\e[${lines}A\e[1G${preprompt}${clr}\e8"
+		print -Pn "${clr_prev_preprompt}\e[${lines}A\e[${COLUMNS}D${preprompt}${clr}\n"
+
+		if [[ $prompt_subst_status = 'on' ]]; then
+			# re-eanble prompt_subst for expansion on PS1
+			setopt prompt_subst
+		fi
+
+		# redraw prompt (also resets cursor position)
+		zle && zle .reset-prompt
 	fi

-	# store previous preprompt for comparison
-	prompt_pure_last_preprompt=$preprompt
+	# store both unexpanded and expanded preprompt for comparison
+	prompt_pure_last_preprompt=("$preprompt" "${(S%%)preprompt}")
 }

 prompt_pure_precmd() {
@@ -199,9 +193,6 @@ prompt_pure_precmd() {
 	# with the initial preprompt rendering
 	prompt_pure_cmd_timestamp=

-	# check for git arrows
-	prompt_pure_check_git_arrows
-
 	# shows the full path in the title
 	prompt_pure_set_title 'expand-prompt' '%~'

@@ -220,29 +211,46 @@ prompt_pure_precmd() {

 # fastest possible way to check if repo is dirty
 prompt_pure_async_git_dirty() {
-	local untracked_dirty=$1; shift
+	setopt localoptions noshwordsplit
+	local untracked_dirty=$1 dir=$2

 	# use cd -q to avoid side effects of changing directory, e.g. chpwd hooks
-	cd -q "$*"
+	builtin cd -q $dir

-	if [[ "$untracked_dirty" == "0" ]]; then
+	if [[ $untracked_dirty = 0 ]]; then
 		command git diff --no-ext-diff --quiet --exit-code
 	else
 		test -z "$(command git status --porcelain --ignore-submodules -unormal)"
 	fi

-	(( $? )) && echo "%F{red}*%f"
+	return $?
 }

 prompt_pure_async_git_fetch() {
+	setopt localoptions noshwordsplit
 	# use cd -q to avoid side effects of changing directory, e.g. chpwd hooks
-	cd -q "$*"
+	builtin cd -q $1

 	# set GIT_TERMINAL_PROMPT=0 to disable auth prompting for git fetch (git 2.3+)
-	GIT_TERMINAL_PROMPT=0 command git -c gc.auto=0 fetch
+	export GIT_TERMINAL_PROMPT=0
+	# set ssh BachMode to disable all interactive ssh password prompting
+	export GIT_SSH_COMMAND=${GIT_SSH_COMMAND:-"ssh -o BatchMode=yes"}
+
+	command git -c gc.auto=0 fetch &>/dev/null || return 1
+
+	# check arrow status after a successful git fetch
+	prompt_pure_async_git_arrows $1
+}
+
+prompt_pure_async_git_arrows() {
+	setopt localoptions noshwordsplit
+	builtin cd -q $1
+	command git rev-list --left-right --count HEAD...@'{u}'
 }

 prompt_pure_async_tasks() {
+	setopt localoptions noshwordsplit
+
 	# initialize async worker
 	((!${prompt_pure_async_init:-0})) && {
 		async_start_worker "prompt_pure" -u -n
@@ -261,6 +269,7 @@ prompt_pure_async_tasks() {
 		# reset git preprompt variables, switching working tree
 		unset prompt_pure_git_dirty
 		unset prompt_pure_git_last_dirty_check_timestamp
+		prompt_pure_git_arrows=

 		# set the new working tree and prefix with "x" to prevent the creation of a named path by AUTO_NAME_DIRS
 		prompt_pure_current_working_tree="x${working_tree}"
@@ -269,10 +278,12 @@ prompt_pure_async_tasks() {
 	# only perform tasks inside git working tree
 	[[ -n $working_tree ]] || return

+	async_job "prompt_pure" prompt_pure_async_git_arrows $working_tree
+
 	# do not preform git fetch if it is disabled or working_tree == HOME
 	if (( ${PURE_GIT_PULL:-1} )) && [[ $working_tree != $HOME ]]; then
 		# tell worker to do a git fetch
-		async_job "prompt_pure" prompt_pure_async_git_fetch "${working_tree}"
+		async_job "prompt_pure" prompt_pure_async_git_fetch $working_tree
 	fi

 	# if dirty checking is sufficiently fast, tell worker to check it again, or wait for timeout
@@ -280,41 +291,76 @@ prompt_pure_async_tasks() {
 	if (( time_since_last_dirty_check > ${PURE_GIT_DELAY_DIRTY_CHECK:-1800} )); then
 		unset prompt_pure_git_last_dirty_check_timestamp
 		# check check if there is anything to pull
-		async_job "prompt_pure" prompt_pure_async_git_dirty "${PURE_GIT_UNTRACKED_DIRTY:-1}" "${working_tree}"
+		async_job "prompt_pure" prompt_pure_async_git_dirty ${PURE_GIT_UNTRACKED_DIRTY:-1} $working_tree
 	fi
 }

-prompt_pure_async_callback() {
-	local job=$1
-	local output=$3
-	local exec_time=$4
+prompt_pure_check_git_arrows() {
+	setopt localoptions noshwordsplit
+	local arrows left=${1:-0} right=${2:-0}

-	case "${job}" in
+	(( right > 0 )) && arrows+=${PURE_GIT_DOWN_ARROW:-⇣}
+	(( left > 0 )) && arrows+=${PURE_GIT_UP_ARROW:-⇡}
+
+	[[ -n $arrows ]] || return
+	typeset -g REPLY=" $arrows"
+}
+
+prompt_pure_async_callback() {
+	setopt localoptions noshwordsplit
+	local job=$1 code=$2 output=$3 exec_time=$4
+
+	case $job in
 		prompt_pure_async_git_dirty)
-			prompt_pure_git_dirty=$output
-			prompt_pure_preprompt_render
+			local prev_dirty=$prompt_pure_git_dirty
+			if (( code == 0 )); then
+				prompt_pure_git_dirty=
+			else
+				prompt_pure_git_dirty="%F{red}*%f"
+			fi
+
+			[[ $prev_dirty != $prompt_pure_git_dirty ]] && prompt_pure_preprompt_render

 			# When prompt_pure_git_last_dirty_check_timestamp is set, the git info is displayed in a different color.
 			# To distinguish between a "fresh" and a "cached" result, the preprompt is rendered before setting this
 			# variable. Thus, only upon next rendering of the preprompt will the result appear in a different color.
 			(( $exec_time > 2 )) && prompt_pure_git_last_dirty_check_timestamp=$EPOCHSECONDS
 			;;
-		prompt_pure_async_git_fetch)
-			prompt_pure_check_git_arrows
-			prompt_pure_preprompt_render
+		prompt_pure_async_git_fetch|prompt_pure_async_git_arrows)
+			# prompt_pure_async_git_fetch executes prompt_pure_async_git_arrows
+			# after a successful fetch.
+			if (( code == 0 )); then
+				local REPLY
+				prompt_pure_check_git_arrows ${(ps:\t:)output}
+				if [[ $prompt_pure_git_arrows != $REPLY ]]; then
+					prompt_pure_git_arrows=$REPLY
+					prompt_pure_preprompt_render
+				fi
+			fi
 			;;
 	esac
 }

 prompt_pure_setup() {
+	local autoload_name=$1; shift
+
 	# prevent percentage showing up
 	# if output doesn't end with a newline
 	export PROMPT_EOL_MARK=''

 	prompt_opts=(subst percent)

+	# if autoload_name or eval context differ, pure wasn't autoloaded via
+	# promptinit and we need to take care of setting the options ourselves
+	if [[ $autoload_name != prompt_pure_setup ]] || [[ $zsh_eval_context[-2] != loadautofunc ]]; then
+		# borrowed from `promptinit`, set the pure prompt options
+		setopt noprompt{bang,cr,percent,subst} "prompt${^prompt_opts[@]}"
+	fi
+
 	zmodload zsh/datetime
 	zmodload zsh/zle
+	zmodload zsh/parameter
+
 	autoload -Uz add-zsh-hook
 	autoload -Uz vcs_info
 	autoload -Uz async && async
@@ -345,7 +391,7 @@ prompt_pure_setup() {
 	[[ $UID -eq 0 ]] && prompt_pure_username=' %F{white}%n%f%F{242}@%m%f'

 	# prompt turns red if the previous command didn't exit with 0
-	PROMPT="%(?.%F{magenta}.%F{red})${PURE_PROMPT_SYMBOL:-❯}%f "
+	PROMPT='%(?.%F{magenta}.%F{red})${PURE_PROMPT_SYMBOL:-❯}%f '
 }

-prompt_pure_setup "$@"
+prompt_pure_setup "$0" "$@"
--- a/readme.md
+++ b/readme.md
@@ -2,7 +2,7 @@

 > Pretty, minimal and fast ZSH prompt

-![](screenshot.png)
+<img src="screenshot.png" width="864">


 ## Overview
@@ -11,10 +11,10 @@ Most prompts are cluttered, ugly and slow. I wanted something visually pleasing

 ### Why?

- Comes with the perfect prompt character.  
+- Comes with the perfect prompt character.
  Author went through the whole Unicode range to find it.
 - Shows `git` branch and whether it's dirty (with a `*`).
- Indicates when you have unpushed/unpulled `git` commits with up/down arrows.
+- Indicates when you have unpushed/unpulled `git` commits with up/down arrows. *(Check is done asynchronously!)*
 - Prompt character turns red if the last command didn't exit with `0`.
 - Command execution time will be displayed if it exceeds the set threshold.
 - Username and host only displayed when in an SSH session.
@@ -24,11 +24,11 @@ Most prompts are cluttered, ugly and slow. I wanted something visually pleasing

 ## Install

-Can be installed with `npm` or manually. Requires git 2.0.0+ and ZSH 5.0.0+.
+Can be installed with `npm` or manually. Requires Git 2.0.0+ and ZSH 5.2+. Older versions of ZSH are known to work, but they are **not** recommended.

 ### npm

-```
+```console
 $ npm install --global pure-prompt
 ```

@@ -39,7 +39,7 @@ That's it. Skip to [Getting started](#getting-started).
 1. Either…
  - Clone this repo
  - add it as a submodule, or
-  - just download `pure.zsh`
+  - just download `pure.zsh` and `async.zsh`

 2. Symlink `pure.zsh` to somewhere in [`$fpath`](http://www.refining-linux.org/archives/46/ZSH-Gem-12-Autoloading-functions/) with the name `prompt_pure_setup`.

@@ -47,7 +47,7 @@ That's it. Skip to [Getting started](#getting-started).

 #### Example

-```
+```console
 $ ln -s "$PWD/pure.zsh" /usr/local/share/zsh/site-functions/prompt_pure_setup
 $ ln -s "$PWD/async.zsh" /usr/local/share/zsh/site-functions/async
 ```
@@ -62,7 +62,7 @@ fpath=( "$HOME/.zfunctions" $fpath )

 Then install the theme there:

-```sh
+```console
 $ ln -s "$PWD/pure.zsh" "$HOME/.zfunctions/prompt_pure_setup"
 $ ln -s "$PWD/async.zsh" "$HOME/.zfunctions/async"
 ```
@@ -74,7 +74,7 @@ Initialize the prompt system (if not so already) and choose `pure`:

 ```sh
 # .zshrc
-autoload -U promptinit && promptinit
+autoload -U promptinit; promptinit
 prompt pure
 ```

@@ -114,7 +114,7 @@ Defines the git up arrow symbol. The default value is `⇡`.
 ```sh
 # .zshrc

-autoload -U promptinit && promptinit
+autoload -U promptinit; promptinit

 # optionally define some options
 PURE_CMD_MAX_EXEC_TIME=10
@@ -125,33 +125,66 @@ prompt pure

 ## Tips

-[Tomorrow Night Eighties](https://github.com/chriskempson/tomorrow-theme) theme with the [Droid Sans Mono](http://www.google.com/webfonts/specimen/Droid+Sans+Mono) font (15pt) is a beautiful combination, as seen in the screenshot above. Just make sure you have anti-aliasing enabled in your Terminal.
+In the screenshot you see Pure running in [Hyper](https://hyper.is) with the [hyper-snazzy](https://github.com/sindresorhus/hyper-snazzy) theme and Menlo font.

-To have commands colorized as seen in the screenshot install [zsh-syntax-highlighting](https://github.com/zsh-users/zsh-syntax-highlighting).
+The [Tomorrow Night Eighties](https://github.com/chriskempson/tomorrow-theme) theme with the [Droid Sans Mono](https://fonts.google.com/specimen/Droid+Sans+Mono) font (15pt) is also a [nice combination](https://github.com/sindresorhus/pure/blob/95ee3e7618c6e2162a1e3cdac2a88a20ac3beb27/screenshot.png).<br>
+*Just make sure you have anti-aliasing enabled in your terminal.*
+
+To have commands colorized as seen in the screenshot, install [zsh-syntax-highlighting](https://github.com/zsh-users/zsh-syntax-highlighting).


 ## Integration

 ### [oh-my-zsh](https://github.com/robbyrussell/oh-my-zsh)

-1. Remove competing theme included in oh-my-zsh `~/.oh-my-zsh/themes/pure.zsh-theme`
-2. Symlink (or copy) `pure.zsh` to `~/.oh-my-zsh/custom/pure.zsh-theme`
-3. Symlink (or copy) `async.zsh` to `~/.oh-my-zsh/custom/async.zsh`
-4. Add `ZSH_THEME="pure"` to your `.zshrc` file.
+1. Symlink (or copy) `pure.zsh` to `~/.oh-my-zsh/custom/pure.zsh-theme`.
+2. Symlink (or copy) `async.zsh` to `~/.oh-my-zsh/custom/async.zsh`.
+3. Set `ZSH_THEME="pure"` in your `.zshrc` file.

-### [prezto](https://github.com/sorin-ionescu/prezto)
+Or skip the `oh-my-zsh` integration above and simply:
+
+1. Set `ZSH_THEME=""` in your `.zshrc` to disable oh-my-zsh themes.
+2. Follow the Pure [Install](#install) instructions.
+
+### [prezto](https://github.com/zsh-users/prezto)
+
+Pure is bundled with Prezto. No need to install it.

 Set `zstyle ':prezto:module:prompt' theme 'pure'` in `~/.zpreztorc`.

+### [zim](https://github.com/Eriner/zim)
+
+Pure is bundled with Zim. No need to install it.
+
+Set `zprompt_theme='pure'` in `~/.zimrc`.
+
 ### [antigen](https://github.com/zsh-users/antigen)

 Update your `.zshrc` file with the following two lines (order matters). Do not use the `antigen theme` function.

-```
+```sh
 antigen bundle mafredri/zsh-async
 antigen bundle sindresorhus/pure
 ```

+### [antibody](https://github.com/getantibody/antibody)
+
+Update your `.zshrc` file with the following two lines (order matters):
+
+```sh
+antibody bundle mafredri/zsh-async
+antibody bundle sindresorhus/pure
+```
+
+### [zplug](https://github.com/zplug/zplug)
+
+Update your `.zshrc` file with the following two lines:
+
+```sh
+zplug mafredri/zsh-async, from:github
+zplug sindresorhus/pure, use:pure.zsh, from:github, as:theme
+```
+
 ## FAQ

 ### My preprompt is missing when I clear the screen with Ctrl+L
@@ -171,15 +204,26 @@ Using `git pull` when you get the username prompt should help you to break the l

 #### Gentoo

-```
-sudo sh -c "echo 'SANDBOX_WRITE=\"/dev/ptmx\"' > /etc/sandbox.d/10zsh"
-sudo emerge -1 zsh
+```console
+$ sudo sh -c "echo 'SANDBOX_WRITE=\"/dev/ptmx\"' > /etc/sandbox.d/10zsh"
+$ sudo emerge -1 zsh
 ```

 #### FreeBSD 10.1

 On a default setup, running the command `kldload pty` should do the trick. If you have a custom kernel, you might need to add `device pty` to the configuration file ([example](https://github.com/nbari/freebsd/blob/58646a9c3c4aaabf6f6467ff505f27f09e29dc75/kernels/xen.kernel#L188)).

+## Ports
+
+* **Bash**
+	* [sapegin/dotfiles](https://github.com/sapegin/dotfiles)’s [prompt](https://github.com/sapegin/dotfiles/blob/dd063f9c30de7d2234e8accdb5272a5cc0a3388b/includes/bash_prompt.bash) and [color theme](https://github.com/sapegin/dotfiles/tree/master/color) for `Terminal.app`.
+* **Fish**
+	* [brandonweiss/pure.fish](https://github.com/brandonweiss/pure.fish): a Pure-inspired prompt for Fish, not intended to have feature parity.
+	* [rafaelrinaldi/pure](https://github.com/rafaelrinaldi/pure), support for bare Fish and various framework ([Oh-My-Fish](https://github.com//oh-my-fish/oh-my-fish), [Fisherman](https://github.com//fisherman/fisherman) and [Wahoo](https://github.com//bucaran/wahoo)).
+* **Zsh**
+  * [therealklanni/purity](https://github.com/therealklanni/purity): a more compact current working directory, important details on the main prompt line, and extra Git indicators.
+  * [intelfx/pure](https://github.com/intelfx/pure): Solarized-friendly colors, highly verbose and fully async Git integration
+
 ## Team

 [![Sindre Sorhus](https://avatars.githubusercontent.com/u/170270?v=3&s=100)](http://sindresorhus.com) | [![Mathias Fredriksson](https://avatars.githubusercontent.com/u/147409?v=3&s=100)](https://github.com/mafredri)
--- a/screenshot.png
+++ b/screenshot.png