Make sure GPG-agent does not mess up the TTY (#645)

Co-authored-by: Sindre Sorhus <[email protected]>

Author: sheeviZi

pure.zsh

@@ -324,6 +324,13 @@ prompt_pure_async_git_fetch() {
 	# Set SSH `BachMode` to disable all interactive SSH password prompting.
 	export GIT_SSH_COMMAND="${GIT_SSH_COMMAND:-"ssh"} -o BatchMode=yes"
 
+	# If gpg-agent is set to handle SSH keys for `git fetch`, make
+	# sure it uses this zpty instead of corrupting the parent TTY.
+	export GPG_TTY=$TTY
+
+	# Tell the child process to not expect any input from this zpty.
+	exec /dev/null > $TTY
+
 	local -a remote
 	if ((only_upstream)); then
 		local ref