Clear async global variables on successful response

If _ZSH_AUTOSUGGEST_ASYNC_FD is not cleared, something else may open the
file descriptor pointed to by it. And then the next call into
_zsh_autosuggest_async_request will close it causing trouble.

It seems like good practice to clean up _ZSH_AUTOSUGGEST_CHILD_PID as
well, though it's not directly causing any known problems at the moment.

I was able to produce errors with ZSH_AUTOSUGGEST_MANUAL_REBIND active
and sourcing a file async-widget-setup.zsh after the first precmd with
the plugin active. If manual rebind is not active or if the widgets are
created before the first precmd, then zsh-autosuggestions wraps the
widgets and for some reason we don't seem to get any fd conflicts.

The .zshrc:

```
ZSH_AUTOSUGGEST_MANUAL_REBIND=true
source zsh-autosuggestions.zsh
```

and async-widget-setup.zsh:

```
function async-widget-fork() {
	exec {fd}< <(echo foo)
	zle -M "opened: $fd, autosuggest fd: $_ZSH_AUTOSUGGEST_ASYNC_FD"
}

function async-widget-read() {
	zle -M "reading from $fd: $(cat <&$fd)"
}

zle -N async-widget-fork
zle -N async-widget-read

bindkey ^A async-widget-fork
bindkey ^B async-widget-read
```

Then run `ZDOTDIR=$PWD zsh` and run `source async-widget-setup.zsh`. At
the next prompt, type one character e.g. "a" to trigger an async
request/response cycle. This leaves _ZSH_AUTOSUGGEST_ASYNC_FD set to the
stale file descriptor number. Then press ^A to activate the fork. This
will set the fd parameter to the same number as
_ZSH_AUTOSUGGEST_ASYNC_FD. Then type another character e.g. "a" to
trigger an async request. This will print a "No handler installed" error
and close the file descriptor pointed to by both
_ZSH_AUTOSUGGEST_ASYNC_FD and fd. Pressing ^B at this point will fail to
read with a "bad file descriptor" error.

.gitignore

@@ -1,2 +0,0 @@
-# zsh word code files
-*.zwc

CHANGELOG.md

@@ -1,12 +1,5 @@
 # Changelog
 
-## v0.7.1
-- Clear POSTDISPLAY instead of unsetting (#634)
-- Always reset async file descriptor after consuming it (#630)
-- Always use builtin `exec` (#628)
-- Add `history-beginning-search-*-end` widgets to clear widget list (#619)
-- Switch CI from Circle CI to GitHub Actions
-
 ## v0.7.0
 - Enable asynchronous mode by default (#498)
 - No longer wrap user widgets starting with `autosuggest-` prefix (#496)

INSTALL.md

@@ -3,21 +3,19 @@
 * [Packages](#packages)
 * [Antigen](#antigen)
 * [Oh My Zsh](#oh-my-zsh)
-* [HomeBrew](#homebrew)
 * [Manual](#manual-git-clone)
 
 ## Packages
 
 | System  | Package |
 | ------------- | ------------- |
-| Alpine Linux | [zsh-autosuggestions](https://pkgs.alpinelinux.org/packages?name=zsh-autosuggestions) |
 | Debian / Ubuntu | [zsh-autosuggestions OBS repository](https://software.opensuse.org/download.html?project=shells%3Azsh-users%3Azsh-autosuggestions&package=zsh-autosuggestions) |
 | Fedora / CentOS / RHEL / Scientific Linux | [zsh-autosuggestions OBS repository](https://software.opensuse.org/download.html?project=shells%3Azsh-users%3Azsh-autosuggestions&package=zsh-autosuggestions) |
 | OpenSUSE / SLE | [zsh-autosuggestions OBS repository](https://software.opensuse.org/download.html?project=shells%3Azsh-users%3Azsh-autosuggestions&package=zsh-autosuggestions) |
 | Arch Linux / Manjaro / Antergos / Hyperbola | [zsh-autosuggestions](https://www.archlinux.org/packages/zsh-autosuggestions), [zsh-autosuggestions-git](https://aur.archlinux.org/packages/zsh-autosuggestions-git) |
-| NixOS | [zsh-autosuggestions](https://github.com/NixOS/nixpkgs/blob/master/pkgs/by-name/zs/zsh-autosuggestions/package.nix) |
+| NixOS | [zsh-autosuggestions](https://github.com/NixOS/nixpkgs/blob/master/pkgs/shells/zsh/zsh-autosuggestions/default.nix) |
 | Void Linux | [zsh-autosuggestions](https://github.com/void-linux/void-packages/blob/master/srcpkgs/zsh-autosuggestions/template) |
-| Mac OS | [homebrew](https://github.com/Homebrew/homebrew-core/blob/master/Formula/z/zsh-autosuggestions.rb)  |
+| Mac OS | [homebrew](https://github.com/Homebrew/homebrew-core/blob/master/Formula/zsh-autosuggestions.rb)  |
 | NetBSD | [pkgsrc](http://ftp.netbsd.org/pub/pkgsrc/current/pkgsrc/shells/zsh-autosuggestions/README.html)  |
 
 ## Antigen
@@ -49,21 +47,6 @@
 
 3. Start a new terminal session.
 
-## Homebrew
-
-1. Install command: 
-    ```sh
-    brew install zsh-autosuggestions
-    ```
-
-2. To activate the autosuggestions, add the following at the end of your .zshrc: 
-    
-    ```sh
-    source $(brew --prefix)/share/zsh-autosuggestions/zsh-autosuggestions.zsh
-    ```
-
-3. Start a new terminal session.
-
 ## Manual (Git Clone)
 
 1. Clone this repository somewhere on your machine. This guide will assume `~/.zsh/zsh-autosuggestions`.

Makefile

@@ -1,4 +1,4 @@
-SRC_DIR := ./src
+SRC_DIR    := ./src
 
 SRC_FILES := \
 	$(SRC_DIR)/config.zsh \

README.md

@@ -6,6 +6,7 @@ It suggests commands as you type based on history and completions.
 
 Requirements: Zsh v4.3.11 or later
 
+[![CircleCI](https://img.shields.io/circleci/build/github/zsh-users/zsh-autosuggestions.svg)](https://circleci.com/gh/zsh-users/zsh-autosuggestions)
 [![Chat on Gitter](https://img.shields.io/gitter/room/zsh-users/zsh-autosuggestions.svg)](https://gitter.im/zsh-users/zsh-autosuggestions)
 
 <a href="https://asciinema.org/a/37390" target="_blank"><img src="https://asciinema.org/a/37390.png" width="400" /></a>
@@ -52,7 +53,7 @@ For more info, read the Character Highlighting section of the zsh manual: `man z
 `ZSH_AUTOSUGGEST_STRATEGY` is an array that specifies how suggestions should be generated. The strategies in the array are tried successively until a suggestion is found. There are currently three built-in strategies to choose from:
 
 - `history`: Chooses the most recent match from history.
-- `completion`: Chooses a suggestion based on what tab-completion would suggest. (requires `zpty` module, which is included with zsh since 4.0.1)
+- `completion`: Chooses a suggestion based on what tab-completion would suggest. (requires `zpty` module)
 - `match_prev_cmd`: Like `history`, but chooses the most recent match whose preceding history item matches the most recently executed command ([more info](src/strategies/match_prev_cmd.zsh)). Note that this strategy won't work as expected with ZSH options that don't preserve the history order such as `HIST_IGNORE_ALL_DUPS` or `HIST_EXPIRE_DUPS_FIRST`.
 
 For example, setting `ZSH_AUTOSUGGEST_STRATEGY=(history completion)` will first try to find a suggestion from your history, but, if it can't find a match, will find a suggestion from the completion engine.

VERSION

@@ -1 +1 @@
-v0.7.1
+v0.7.0

src/async.zsh

@@ -11,35 +11,24 @@ _zsh_autosuggest_async_request() {
 	# If we've got a pending request, cancel it
 	if [[ -n "$_ZSH_AUTOSUGGEST_ASYNC_FD" ]] && { true <&$_ZSH_AUTOSUGGEST_ASYNC_FD } 2>/dev/null; then
 		# Close the file descriptor and remove the handler
-		builtin exec {_ZSH_AUTOSUGGEST_ASYNC_FD}<&-
+		exec {_ZSH_AUTOSUGGEST_ASYNC_FD}<&-
 		zle -F $_ZSH_AUTOSUGGEST_ASYNC_FD
 
 		# We won't know the pid unless the user has zsh/system module installed
-		if [[ -n "$_ZSH_AUTOSUGGEST_CHILD_PID" ]]; then
-			# Zsh will make a new process group for the child process only if job
-			# control is enabled (MONITOR option)
-			if [[ -o MONITOR ]]; then
-				# Send the signal to the process group to kill any processes that may
-				# have been forked by the suggestion strategy
-				kill -TERM -$_ZSH_AUTOSUGGEST_CHILD_PID 2>/dev/null
-			else
-				# Kill just the child process since it wasn't placed in a new process
-				# group. If the suggestion strategy forked any child processes they may
-				# be orphaned and left behind.
-				kill -TERM $_ZSH_AUTOSUGGEST_CHILD_PID 2>/dev/null
-			fi
+		if (( _ZSH_AUTOSUGGEST_CHILD_PID )); then
+			kill -TERM -- $_ZSH_AUTOSUGGEST_CHILD_PID 2>/dev/null
 		fi
 	fi
 
 	# Fork a process to fetch a suggestion and open a pipe to read from it
-	builtin exec {_ZSH_AUTOSUGGEST_ASYNC_FD}< <(
-		# Tell parent process our pid
-		echo $sysparams[pid]
+	exec {_ZSH_AUTOSUGGEST_ASYNC_FD}< <(
+		# Tell parent process our pid if we can
+		echo ${sysparams[pid]:-}
 
 		# Fetch and print the suggestion
 		local suggestion
 		_zsh_autosuggest_fetch_suggestion "$1"
-		echo -nE "$suggestion"
+		echo -nE - "$suggestion"
 	)
 
 	# There's a weird bug here where ^C stops working unless we force a fork
@@ -50,6 +39,15 @@ _zsh_autosuggest_async_request() {
 	# Read the pid from the child process
 	read _ZSH_AUTOSUGGEST_CHILD_PID <&$_ZSH_AUTOSUGGEST_ASYNC_FD
 
+	# Zsh will make a new process group for the child process only if job
+	# control is enabled (MONITOR option)
+	if [[ -o MONITOR ]]; then
+		# If we need to kill the background process in the future, we'll send
+		# SIGTERM to the process group to kill any processes that may have been
+		# forked by the suggestion strategy
+		_ZSH_AUTOSUGGEST_CHILD_PID=${_ZSH_AUTOSUGGEST_CHILD_PID:+-$_ZSH_AUTOSUGGEST_CHILD_PID}
+	fi
+
 	# When the fd is readable, call the response handler
 	zle -F "$_ZSH_AUTOSUGGEST_ASYNC_FD" _zsh_autosuggest_async_response
 }
@@ -60,18 +58,20 @@ _zsh_autosuggest_async_request() {
 _zsh_autosuggest_async_response() {
 	emulate -L zsh
 
+	typeset -g _ZSH_AUTOSUGGEST_ASYNC_FD _ZSH_AUTOSUGGEST_CHILD_PID
 	local suggestion
 
-	if [[ -z "$2" || "$2" == "hup" ]]; then
+	if [[ $# == 1 || "$2" == "hup" ]]; then
 		# Read everything from the fd and give it as a suggestion
 		IFS='' read -rd '' -u $1 suggestion
 		zle autosuggest-suggest -- "$suggestion"
 
 		# Close the fd
-		builtin exec {1}<&-
+		exec {1}<&-
+		_ZSH_AUTOSUGGEST_ASYNC_FD=
+		_ZSH_AUTOSUGGEST_ASYNC_PID=
 	fi
 
 	# Always remove the handler
-	zle -F "$1"
-	_ZSH_AUTOSUGGEST_ASYNC_FD=
+	zle -F $1
 }

src/config.zsh

@@ -28,8 +28,6 @@ typeset -g ZSH_AUTOSUGGEST_ORIGINAL_WIDGET_PREFIX=autosuggest-orig-
 		history-search-backward
 		history-beginning-search-forward
 		history-beginning-search-backward
-		history-beginning-search-forward-end
-		history-beginning-search-backward-end
 		history-substring-search-up
 		history-substring-search-down
 		up-line-or-beginning-search

src/widgets.zsh

@@ -30,7 +30,7 @@ _zsh_autosuggest_toggle() {
 # Clear the suggestion
 _zsh_autosuggest_clear() {
 	# Remove the suggestion
-	POSTDISPLAY=
+	unset POSTDISPLAY
 
 	_zsh_autosuggest_invoke_original_widget $@
 }
@@ -47,7 +47,7 @@ _zsh_autosuggest_modify() {
 	local orig_postdisplay="$POSTDISPLAY"
 
 	# Clear suggestion while waiting for next one
-	POSTDISPLAY=
+	unset POSTDISPLAY
 
 	# Original widget may modify the buffer
 	_zsh_autosuggest_invoke_original_widget $@
@@ -102,7 +102,7 @@ _zsh_autosuggest_suggest() {
 	if [[ -n "$suggestion" ]] && (( $#BUFFER )); then
 		POSTDISPLAY="${suggestion#$BUFFER}"
 	else
-		POSTDISPLAY=
+		unset POSTDISPLAY
 	fi
 }
 
@@ -128,7 +128,7 @@ _zsh_autosuggest_accept() {
 	BUFFER="$BUFFER$POSTDISPLAY"
 
 	# Remove the suggestion
-	POSTDISPLAY=
+	unset POSTDISPLAY
 
 	# Run the original widget before manually moving the cursor so that the
 	# cursor movement doesn't make the widget do something unexpected
@@ -151,7 +151,7 @@ _zsh_autosuggest_execute() {
 	BUFFER="$BUFFER$POSTDISPLAY"
 
 	# Remove the suggestion
-	POSTDISPLAY=
+	unset POSTDISPLAY
 
 	# Call the original `accept-line` to handle syntax highlighting or
 	# other potential custom behavior

zsh-autosuggestions.zsh

@@ -1,6 +1,6 @@
 # Fish-like fast/unobtrusive autosuggestions for zsh.
 # https://github.com/zsh-users/zsh-autosuggestions
-# v0.7.1
+# v0.7.0
 # Copyright (c) 2013 Thiago de Arruda
 # Copyright (c) 2016-2021 Eric Freese
 # 
@@ -54,8 +54,6 @@ typeset -g ZSH_AUTOSUGGEST_ORIGINAL_WIDGET_PREFIX=autosuggest-orig-
 		history-search-backward
 		history-beginning-search-forward
 		history-beginning-search-backward
-		history-beginning-search-forward-end
-		history-beginning-search-backward-end
 		history-substring-search-up
 		history-substring-search-down
 		up-line-or-beginning-search
@@ -294,7 +292,7 @@ _zsh_autosuggest_toggle() {
 # Clear the suggestion
 _zsh_autosuggest_clear() {
 	# Remove the suggestion
-	POSTDISPLAY=
+	unset POSTDISPLAY
 
 	_zsh_autosuggest_invoke_original_widget $@
 }
@@ -311,7 +309,7 @@ _zsh_autosuggest_modify() {
 	local orig_postdisplay="$POSTDISPLAY"
 
 	# Clear suggestion while waiting for next one
-	POSTDISPLAY=
+	unset POSTDISPLAY
 
 	# Original widget may modify the buffer
 	_zsh_autosuggest_invoke_original_widget $@
@@ -366,7 +364,7 @@ _zsh_autosuggest_suggest() {
 	if [[ -n "$suggestion" ]] && (( $#BUFFER )); then
 		POSTDISPLAY="${suggestion#$BUFFER}"
 	else
-		POSTDISPLAY=
+		unset POSTDISPLAY
 	fi
 }
 
@@ -392,7 +390,7 @@ _zsh_autosuggest_accept() {
 	BUFFER="$BUFFER$POSTDISPLAY"
 
 	# Remove the suggestion
-	POSTDISPLAY=
+	unset POSTDISPLAY
 
 	# Run the original widget before manually moving the cursor so that the
 	# cursor movement doesn't make the widget do something unexpected
@@ -415,7 +413,7 @@ _zsh_autosuggest_execute() {
 	BUFFER="$BUFFER$POSTDISPLAY"
 
 	# Remove the suggestion
-	POSTDISPLAY=
+	unset POSTDISPLAY
 
 	# Call the original `accept-line` to handle syntax highlighting or
 	# other potential custom behavior
@@ -768,35 +766,24 @@ _zsh_autosuggest_async_request() {
 	# If we've got a pending request, cancel it
 	if [[ -n "$_ZSH_AUTOSUGGEST_ASYNC_FD" ]] && { true <&$_ZSH_AUTOSUGGEST_ASYNC_FD } 2>/dev/null; then
 		# Close the file descriptor and remove the handler
-		builtin exec {_ZSH_AUTOSUGGEST_ASYNC_FD}<&-
+		exec {_ZSH_AUTOSUGGEST_ASYNC_FD}<&-
 		zle -F $_ZSH_AUTOSUGGEST_ASYNC_FD
 
 		# We won't know the pid unless the user has zsh/system module installed
-		if [[ -n "$_ZSH_AUTOSUGGEST_CHILD_PID" ]]; then
-			# Zsh will make a new process group for the child process only if job
-			# control is enabled (MONITOR option)
-			if [[ -o MONITOR ]]; then
-				# Send the signal to the process group to kill any processes that may
-				# have been forked by the suggestion strategy
-				kill -TERM -$_ZSH_AUTOSUGGEST_CHILD_PID 2>/dev/null
-			else
-				# Kill just the child process since it wasn't placed in a new process
-				# group. If the suggestion strategy forked any child processes they may
-				# be orphaned and left behind.
-				kill -TERM $_ZSH_AUTOSUGGEST_CHILD_PID 2>/dev/null
-			fi
+		if (( _ZSH_AUTOSUGGEST_CHILD_PID )); then
+			kill -TERM -- $_ZSH_AUTOSUGGEST_CHILD_PID 2>/dev/null
 		fi
 	fi
 
 	# Fork a process to fetch a suggestion and open a pipe to read from it
-	builtin exec {_ZSH_AUTOSUGGEST_ASYNC_FD}< <(
-		# Tell parent process our pid
-		echo $sysparams[pid]
+	exec {_ZSH_AUTOSUGGEST_ASYNC_FD}< <(
+		# Tell parent process our pid if we can
+		echo ${sysparams[pid]:-}
 
 		# Fetch and print the suggestion
 		local suggestion
 		_zsh_autosuggest_fetch_suggestion "$1"
-		echo -nE "$suggestion"
+		echo -nE - "$suggestion"
 	)
 
 	# There's a weird bug here where ^C stops working unless we force a fork
@@ -807,6 +794,15 @@ _zsh_autosuggest_async_request() {
 	# Read the pid from the child process
 	read _ZSH_AUTOSUGGEST_CHILD_PID <&$_ZSH_AUTOSUGGEST_ASYNC_FD
 
+	# Zsh will make a new process group for the child process only if job
+	# control is enabled (MONITOR option)
+	if [[ -o MONITOR ]]; then
+		# If we need to kill the background process in the future, we'll send
+		# SIGTERM to the process group to kill any processes that may have been
+		# forked by the suggestion strategy
+		_ZSH_AUTOSUGGEST_CHILD_PID=${_ZSH_AUTOSUGGEST_CHILD_PID:+-$_ZSH_AUTOSUGGEST_CHILD_PID}
+	fi
+
 	# When the fd is readable, call the response handler
 	zle -F "$_ZSH_AUTOSUGGEST_ASYNC_FD" _zsh_autosuggest_async_response
 }
@@ -817,20 +813,22 @@ _zsh_autosuggest_async_request() {
 _zsh_autosuggest_async_response() {
 	emulate -L zsh
 
+	typeset -g _ZSH_AUTOSUGGEST_ASYNC_FD _ZSH_AUTOSUGGEST_CHILD_PID
 	local suggestion
 
-	if [[ -z "$2" || "$2" == "hup" ]]; then
+	if [[ $# == 1 || "$2" == "hup" ]]; then
 		# Read everything from the fd and give it as a suggestion
 		IFS='' read -rd '' -u $1 suggestion
 		zle autosuggest-suggest -- "$suggestion"
 
 		# Close the fd
-		builtin exec {1}<&-
+		exec {1}<&-
+		_ZSH_AUTOSUGGEST_ASYNC_FD=
+		_ZSH_AUTOSUGGEST_ASYNC_PID=
 	fi
 
 	# Always remove the handler
-	zle -F "$1"
-	_ZSH_AUTOSUGGEST_ASYNC_FD=
+	zle -F $1
 }
 
 #--------------------------------------------------------------------#