Check for TMUX only once, check whether $TMUX is writeable

Fixes #801

powerline/bindings/bash/powerline.sh

@@ -9,24 +9,35 @@ if test -z "${POWERLINE_COMMAND}" ; then
 	fi
 fi
 
-_powerline_tmux_setenv() {
+_powerline_init_tmux_support() {
-	if [[ -n "$TMUX" ]]; then
+	# Note: `test -w ""` returns false, so first condition may be removed
-		tmux setenv -g TMUX_"$1"_`tmux display -p "#D" | tr -d %` "$2"
+	if test -n "$TMUX" && test -w "$TMUX" ; then
-		tmux refresh -S
+		# TMUX variable may be unset to create new tmux session inside this one
-	fi
+		_POWERLINE_TMUX="$TMUX"
-}
 
-_POWERLINE_SAVED_PWD=
+		_powerline_tmux_setenv() {
+			TMUX="$_POWERLINE_TMUX" tmux setenv -g TMUX_"$1"_`tmux display -p "#D" | tr -d %` "$2"
+			TMUX="$_POWERLINE_TMUX" tmux refresh -S
+		}
 
-_powerline_tmux_set_pwd() {
+		_powerline_tmux_set_pwd() {
 			if test "x$_POWERLINE_SAVED_PWD" != "x$PWD" ; then
 				_POWERLINE_SAVED_PWD="$PWD"
 				_powerline_tmux_setenv PWD "$PWD"
 			fi
-}
+		}
 
-_powerline_tmux_set_columns() {
+		_powerline_tmux_set_columns() {
 			_powerline_tmux_setenv COLUMNS "$COLUMNS"
+		}
+
+		trap "_powerline_tmux_set_columns" SIGWINCH
+		_powerline_tmux_set_columns
+	else
+		_powerline_tmux_set_pwd() {
+			return 0
+		}
+	fi
 }
 
 _powerline_prompt() {
@@ -36,8 +47,7 @@ _powerline_prompt() {
 	return $last_exit_code
 }
 
-trap "_powerline_tmux_set_columns" SIGWINCH
-_powerline_tmux_set_columns
-
 [[ "$PROMPT_COMMAND" != "${PROMPT_COMMAND/_powerline_prompt/}" ]] ||
 	export PROMPT_COMMAND="${PROMPT_COMMAND}"$'\n'"_powerline_prompt"
+
+_powerline_init_tmux_support

powerline/bindings/fish/powerline-setup.fish

@@ -20,12 +20,11 @@ function powerline-setup
 		"
 	end
 	_powerline_update
+	if test -w "$TMUX"
 		function _powerline_tmux_setenv
-		if test -n "$TMUX"
 			tmux setenv -g TMUX_$argv[1]_(tmux display -p "#D" | tr -d "%") "$argv[2]"
 			tmux refresh -S
 		end
-	end
 		function --on-variable PWD _powerline_tmux_set_pwd
 			_powerline_tmux_setenv PWD "$PWD"
 		end
@@ -34,4 +33,5 @@ function powerline-setup
 		end
 		_powerline_tmux_set_columns
 		_powerline_tmux_set_pwd
+	end
 end

powerline/bindings/tcsh/powerline.tcsh

@@ -14,7 +14,7 @@ if ! $?POWERLINE_COMMAND then
 		setenv POWERLINE_COMMAND $POWERLINE_SOURCED:h:h:h:h:q/scripts/powerline
 	endif
 endif
-alias _powerline_tmux_set_pwd 'if $?TMUX tmux setenv -g TMUX_PWD_`tmux display -p "#D" | tr -d %` $PWD:q ; if $?TMUX tmux refresh -S'
+alias _powerline_tmux_set_pwd 'if ( $?TMUX && { test -w $TMUX:q } ) tmux setenv -g TMUX_PWD_`tmux display -p "#D" | tr -d %` $PWD:q ; if ( $?TMUX && { test -w $TMUX:q } ) tmux refresh -S'
 alias _powerline_set_prompt 'set prompt="`$POWERLINE_COMMAND shell left -r tcsh_prompt --last_exit_code=$?`"'
 alias _powerline_set_rprompt 'set rprompt="`$POWERLINE_COMMAND shell right -r tcsh_prompt --last_exit_code=$?` "'
 alias cwdcmd "`alias cwdcmd` ; _powerline_tmux_set_pwd"

powerline/bindings/zsh/powerline.zsh

@@ -8,20 +8,35 @@ if test -z "${POWERLINE_COMMAND}" ; then
 	fi
 fi
 
-_powerline_tmux_setenv() {
+integer _POWERLINE_JOBNUM
+
+_powerline_init_tmux_support() {
 	emulate -L zsh
-	if [[ -n "$TMUX" ]]; then
+	# Note: `test -w ""` returns false, so first condition may be removed
+	if test -n "$TMUX" && test -w "$TMUX" ; then
+		# TMUX variable may be unset to create new tmux session inside this one
+		typeset -g _POWERLINE_TMUX="$TMUX"
+
+		function -g _powerline_tmux_setenv() {
+			emulate -L zsh
+			local -x TMUX="$_POWERLINE_TMUX"
 			tmux setenv -g TMUX_"$1"_$(tmux display -p "#D" | tr -d %) "$2"
 			tmux refresh -S
-	fi
+		}
-}
 
-_powerline_tmux_set_pwd() {
+		function -g _powerline_tmux_set_pwd() {
 			_powerline_tmux_setenv PWD "$PWD"
-}
+		}
 
-_powerline_tmux_set_columns() {
+		function -g _powerline_tmux_set_columns() {
 			_powerline_tmux_setenv COLUMNS "$COLUMNS"
+		}
+
+		chpwd_functions+=( _powerline_tmux_set_pwd )
+		trap "_powerline_tmux_set_columns" SIGWINCH
+		_powerline_tmux_set_columns
+		_powerline_tmux_set_pwd
+	fi
 }
 
 _powerline_precmd() {
@@ -47,7 +62,6 @@ _powerline_setup_prompt() {
 		fi
 	done
 	precmd_functions+=( _powerline_precmd )
-	chpwd_functions+=( _powerline_tmux_set_pwd )
 	_powerline_set_true_keymap_name "${${(Q)${${(z)${"$(bindkey -lL main)"}}[3]}}:-.safe}"
 	if zmodload zsh/zpython &>/dev/null ; then
 		zpython 'from powerline.bindings.zsh import setup as _powerline_setup'
@@ -106,10 +120,7 @@ if [[ "$_POWERLINE_MODE" != vi* ]] ; then
 	export _POWERLINE_DEFAULT_MODE="$_POWERLINE_MODE"
 fi
 
-trap "_powerline_tmux_set_columns" SIGWINCH
-_powerline_tmux_set_columns
-_powerline_tmux_set_pwd
-
 setopt promptpercent
 setopt promptsubst
 _powerline_setup_prompt
+_powerline_init_tmux_support