From eb4ffceefb236edfef72ffc1c387efb3222da9cd Mon Sep 17 00:00:00 2001
From: Koichi Murase <myoga.murase@gmail.com>
Date: Tue, 14 Feb 2023 20:09:24 +0900
Subject: [PATCH] global: work around bash-4.4 no-argument return in trap

---
 ble.pp                             |  2 +-
 blerc.template                     |  2 +-
 contrib                            |  2 +-
 docs/ChangeLog.md                  |  1 +
 lib/core-complete.sh               |  2 +-
 lib/core-syntax.sh                 |  6 ++--
 make_command.sh                    | 57 ++++++++++++++++++------------
 memo/D1405.extract-man.sh          | 10 +++---
 memo/D1589-ConvertAirlineThemes.sh |  8 ++---
 memo/D1645.check-c2w-table.sh      |  4 +--
 memo/D1782.test.sh                 |  4 +--
 note.txt                           | 11 +++---
 src/canvas.sh                      |  6 ++--
 src/decode.sh                      |  8 ++---
 src/edit.sh                        |  5 +--
 src/util.hook.sh                   |  2 +-
 src/util.sh                        | 10 +++---
 17 files changed, 77 insertions(+), 63 deletions(-)

diff --git a/ble.pp b/ble.pp
index dd0d9009..c933b41e 100644
--- a/ble.pp
+++ b/ble.pp
@@ -2337,7 +2337,7 @@ function ble/base/attach-from-PROMPT_COMMAND {
       # #D1354: 入れ子の ble/base/attach-from-PROMPT_COMMAND の時は一番
       #   外側で ble-attach を実行する様にする。3>&2 2>/dev/null のリダ
       #   イレクトにより stdout.off の効果が巻き戻されるのを防ぐ為。
-      [[ ${ble_base_attach_from_prompt_command-} != processing ]] || return
+      [[ ${ble_base_attach_from_prompt_command-} != processing ]] || return 0
     fi
 
     # 既に attach 状態の時は処理はスキップ
diff --git a/blerc.template b/blerc.template
index 8e2e6db4..9d70bd7e 100644
--- a/blerc.template
+++ b/blerc.template
@@ -932,7 +932,7 @@ function blerc/emacs-load-hook {
   #ble-bind -f 'M-C-h' kill-backward-cword
   #ble-bind -f 'M-BS'  kill-backward-cword
 
-  return
+  return 0
 }
 blehook/eval-after-load keymap_emacs blerc/emacs-load-hook
 
diff --git a/contrib b/contrib
index b365f5dd..1444569b 160000
--- a/contrib
+++ b/contrib
@@ -1 +1 @@
-Subproject commit b365f5dd75121b4259d5080d03a2d868f45305d3
+Subproject commit 1444569b50e150b6101bea578b60895682c53469
diff --git a/docs/ChangeLog.md b/docs/ChangeLog.md
index 161abcf1..4b6303e3 100644
--- a/docs/ChangeLog.md
+++ b/docs/ChangeLog.md
@@ -535,6 +535,7 @@
 - edit: update prompts on g2sgr change `#D1906` 40625ac
 - util, decode, vi: fix leak variables `#D1933` 8d5cab8
 - util: support `bleopt debug_idle` `#D1945` fa10184
+- global: work around bash-4.4 no-argument return in trap `#D1970` xxxxxxx
 
 ## Contrib
 
diff --git a/lib/core-complete.sh b/lib/core-complete.sh
index 78d81df3..39b52bd2 100644
--- a/lib/core-complete.sh
+++ b/lib/core-complete.sh
@@ -4048,7 +4048,7 @@ function ble/complete/mandb/search-file {
 
   local path
   ble/complete/mandb/search-file/.extract-path "$command"
-  ble/complete/mandb/search-file/.check "$path" && return
+  ble/complete/mandb/search-file/.check "$path" && return 0
 
   # Get manpaths
   ble/string#split ret : "$MANPATH"
diff --git a/lib/core-syntax.sh b/lib/core-syntax.sh
index 4503a99e..eb0f14e2 100644
--- a/lib/core-syntax.sh
+++ b/lib/core-syntax.sh
@@ -5584,7 +5584,7 @@ function ble/syntax/completion-context/.check-prefix/ctx:quote/.check-container-
       ble/syntax/completion-context/.add argument "$wbeg2"
     elif ((wt==CTX_CPATI)); then # case pattern の内部
       #ble/syntax/completion-context/.add file "$wbeg2"
-      return
+      return 0
     fi
   fi
 }
@@ -7436,7 +7436,7 @@ function ble/highlight/layer:syntax/update {
       _ble_highlight_layer_syntax_active=
       PREV_UMIN=0 PREV_UMAX=${#1}
     fi
-    return
+    return 0
   fi
 
   # 前回 layer:syntax が無効だった時
@@ -7532,7 +7532,7 @@ function ble/highlight/layer:syntax/update {
 }
 
 function ble/highlight/layer:syntax/getg {
-  [[ ! $bleopt_highlight_syntax ]] && return
+  [[ $bleopt_highlight_syntax ]] || return 1
   local i=$1
   if [[ ${_ble_highlight_layer_syntax3_table[i]} ]]; then
     g=${_ble_highlight_layer_syntax3_table[i]}
diff --git a/make_command.sh b/make_command.sh
index 92b139e4..dbad1ffc 100755
--- a/make_command.sh
+++ b/make_command.sh
@@ -1074,6 +1074,8 @@ function sub:check-all {
 #------------------------------------------------------------------------------
 # sub:scan
 
+_make_rex_escseq='(\[[ -?]*[@-~])*'
+
 function sub:scan/grc-source {
   local -a options=(--color --exclude=./{test,memo,ext,wiki,contrib,[TD]????.*} --exclude=\*.{md,awk} --exclude=./{GNUmakefile,make_command.sh})
   grc "${options[@]}" "$@"
@@ -1113,12 +1115,12 @@ function sub:scan/list-command {
 
 function sub:scan/builtin {
   echo "--- $FUNCNAME $1 ---"
-  local command=$1 esc='(\[[ -?]*[@-~])*'
+  local command=$1 esc=$_make_rex_escseq
   sub:scan/list-command --exclude-this --exclude={generate-release-note.sh,lib/test-*.sh,make,ext} "$command" "${@:2}" |
     grep -Ev "$rex_grep_head([[:space:]]*|[[:alnum:][:space:]]*[[:space:]])#|(\b|$esc)(builtin|function)$esc([[:space:]]$esc)+$command(\b|$esc)" |
     grep -Ev "$command(\b|$esc)=" |
     grep -Ev "ble\.sh $esc\($esc$command$esc\)$esc" |
-    sed -E 'h;s/'"$esc"'//g;\Z(\.awk|push|load|==) \b'"$command"'\bZd;g'
+    sed -E 'h;s/'"$_make_rex_escseq"'//g;\Z(\.awk|push|load|==) \b'"$command"'\bZd;g'
 }
 
 function sub:scan/check-todo-mark {
@@ -1164,13 +1166,27 @@ function sub:scan/bash501-arith-base {
   grc '\b10#\$' --exclude={test,ChangeLog.md}
 }
 
+function sub:scan/bash404-no-argument-return {
+  echo "--- $FUNCNAME ---"
+  grc --color 'return[[:space:]]*($|[;|&<>])' --exclude={test,wiki,ChangeLog.md,make,docs,make_command.sh} |
+    sed -E 'h;s/'"$_make_rex_escseq"'//g;s/^[^:]*:[0-9]+:[[:space:]]*//
+
+      \Z@returnZd
+      \Z\) return;Zd
+      \Zreturn;[[:space:]]*$Zd
+      \Zif \(REQ == "[A-Z]+"\)Zd
+      \Z\(return\|ret\)Zd
+      \Z_ble_trap_done=return$Zd
+
+      g'
+}
+
 function sub:scan/bash502-patsub_replacement {
   echo "--- $FUNCNAME ---"
   # bash-5.2 patsub_replacement で ${var/pat/string} の string 中の & が特別な
   # 意味を持つ様になったので、特に意識する場合を除いては quote が必要になった。
-  local esc='(\[[ -?]*[@-~])*'
   grc --color '\$\{[[:alnum:]_]+(\[[^][]*\])?//?([^{}]|\{[^{}]*\})+/[^{}"'\'']*([&$]|\\)' --exclude=./test |
-    sed -E 'h;s/'"$esc"'//g;s/^[^:]*:[0-9]+:[[:space:]]*//
+    sed -E 'h;s/'"$_make_rex_escseq"'//g;s/^[^:]*:[0-9]+:[[:space:]]*//
       \Z//?\$q/\$Q\}Zd
       \Z//?\$q/\$qq\}Zd
       \Z//?\$qq/\$q\}Zd
@@ -1187,7 +1203,7 @@ function sub:scan/bash502-patsub_replacement {
       g'
 
   grc --color '"[^"]*\$\{[[:alnum:]_]+(\[[^][]*\])?//?([^{}]|\{[^{}]*\})+/[^{}"'\'']*"[^"]*([&$]|\\)' --exclude=./test |
-    sed -E 'h;s/'"$esc"'//g;s/^[^:]*:[0-9]+:[[:space:]]*//
+    sed -E 'h;s/'"$_make_rex_escseq"'//g;s/^[^:]*:[0-9]+:[[:space:]]*//
       \Z#D1751Zd
       g'
 }
@@ -1250,9 +1266,8 @@ function sub:scan/array-count-in-arithmetic-expression {
 # unset 変数名 としていると誤って関数が消えることがある。
 function sub:scan/unset-variable {
   echo "--- $FUNCNAME ---"
-  local esc='(\[[ -?]*[@-~])*'
   sub:scan/list-command unset --exclude-this |
-    sed -E 'h;s/'"$esc"'//g;s/^[^:]*:[0-9]+:[[:space:]]*//
+    sed -E 'h;s/'"$_make_rex_escseq"'//g;s/^[^:]*:[0-9]+:[[:space:]]*//
       \Zunset[[:space:]]-[vf]Zd
       \Z^[[:space:]]*#Zd
       \Zunset _ble_init_(version|arg|exit|command)\bZd
@@ -1265,9 +1280,8 @@ function sub:scan/unset-variable {
 }
 function sub:scan/eval-literal {
   echo "--- $FUNCNAME ---"
-  local esc='(\[[ -?]*[@-~])*'
   sub:scan/grc-source 'builtin eval "\$' |
-    sed -E 'h;s/'"$esc"'//g;s/^[^:]*:[0-9]+:[[:space:]]*//
+    sed -E 'h;s/'"$_make_rex_escseq"'//g;s/^[^:]*:[0-9]+:[[:space:]]*//
       \Zeval "(\$[[:alnum:]_]+)+(\[[^]["'\''\$`]+\])?\+?=Zd
       g'
 }
@@ -1284,10 +1298,8 @@ function sub:scan/mistake-_ble_bash {
 
 function sub:scan/command-layout {
   echo "--- $FUNCNAME ---"
-  local esc='(\[[ -?]*[@-~])*'
-
   grc '/(enter-command-layout|\.insert-newline|\.newline)([[:space:]]|$)' --exclude=./{text,ext} --exclude=./make_command.sh --exclude=\*.md --color |
-    sed -E 'h;s/'"$esc"'//g;s/^[^:]*:[0-9]+:[[:space:]]*//
+    sed -E 'h;s/'"$_make_rex_escseq"'//g;s/^[^:]*:[0-9]+:[[:space:]]*//
       \Z^[[:space:]]*#Zd
       \Z^[[:space:]]*function [^[:space:]]* \{$Zd
       \Z[: ]keep-infoZd
@@ -1300,7 +1312,7 @@ function sub:scan/word-splitting-number {
   # #D1835 一般には IFS に整数が含まれるている場合もあるので ${#...} や
   # $((...)) や >&$fd であってもちゃんと quote する必要がある。
   grc '[<>]&\$|([[:space:]]|=\()\$(\(\(|\{#|\?)' --exclude={docs,mwg_pp.awk} |
-    sed -E 'h;s/'"$esc"'//g;s/^[^:]*:[0-9]+:[[:space:]]*//
+    sed -E 'h;s/'"$_make_rex_escseq"'//g;s/^[^:]*:[0-9]+:[[:space:]]*//
       \Z^[^#]*(^|[[:space:]])#Zd
       \Z^([^"]|"[^\#]*")*"[^"]*([& (]\$)Zd
       \Z^[^][]*\[\[[^][]*([& (]\$)Zd
@@ -1318,21 +1330,21 @@ function sub:scan {
     exit
   fi
 
-  local esc='(\[[ -?]*[@-~])*'
+  local esc=$_make_rex_escseq
   local rex_grep_head="^$esc[[:graph:]]+$esc:$esc[[:digit:]]*$esc:$esc"
 
   # builtin return break continue : eval echo unset は unset しているので大丈夫のはず
 
   #sub:scan/builtin 'history'
   sub:scan/builtin 'echo' --exclude=./keymap/vi_test.sh --exclude=./ble.pp |
-    sed -E 'h;s/'"$esc"'//g;s/^[^:]*:[0-9]+:[[:space:]]*//
+    sed -E 'h;s/'"$_make_rex_escseq"'//g;s/^[^:]*:[0-9]+:[[:space:]]*//
       \Z\bstty[[:space:]]+echoZd
       \Zecho \$PPIDZd
       \Zmandb-help=%'\''help echo'\''Zd
       g'
   #sub:scan/builtin '(compopt|type|printf)'
   sub:scan/builtin 'bind' |
-    sed -E 'h;s/'"$esc"'//g;s/^[^:]*:[0-9]+:[[:space:]]*//
+    sed -E 'h;s/'"$_make_rex_escseq"'//g;s/^[^:]*:[0-9]+:[[:space:]]*//
       \Zinvalid bind typeZd
       \Zline = "bind"Zd
       \Z'\''  bindZd
@@ -1341,18 +1353,18 @@ function sub:scan {
       \Zoutputs of the "bind" builtinZd
       g'
   sub:scan/builtin 'read' |
-    sed -E 'h;s/'"$esc"'//g;s/^[^:]*:[0-9]+:[[:space:]]*//
+    sed -E 'h;s/'"$_make_rex_escseq"'//g;s/^[^:]*:[0-9]+:[[:space:]]*//
       \ZDo not read Zd
       \Zfailed to read Zd
       g'
   sub:scan/builtin 'exit' |
-    sed -E 'h;s/'"$esc"'//g;s/^[^:]*:[0-9]+:[[:space:]]*//
+    sed -E 'h;s/'"$_make_rex_escseq"'//g;s/^[^:]*:[0-9]+:[[:space:]]*//
       \Zble.pp.*return 1 2>/dev/null || exit 1Zd
       \Z^[-[:space:][:alnum:]_./:=$#*]+('\''[^'\'']*|"[^"()`]*|([[:space:]]|^)#.*)\bexit\bZd
       \Z\(exit\) ;;Zd
       \Zprint NR; exit;Zd;g'
   sub:scan/builtin 'eval' |
-    sed -E 'h;s/'"$esc"'//g;s/^[^:]*:[0-9]+:[[:space:]]*//
+    sed -E 'h;s/'"$_make_rex_escseq"'//g;s/^[^:]*:[0-9]+:[[:space:]]*//
       \Z\('\''eval'\''\)Zd
       \Zbuiltins1=\(.* eval .*\)Zd
       \Z\^eval --Zd
@@ -1364,7 +1376,7 @@ function sub:scan {
       \ZLINENO=\$_ble_edit_LINENO evalZd
       g'
   sub:scan/builtin 'unset' |
-    sed -E 'h;s/'"$esc"'//g;s/^[^:]*:[0-9]+:[[:space:]]*//
+    sed -E 'h;s/'"$_make_rex_escseq"'//g;s/^[^:]*:[0-9]+:[[:space:]]*//
       \Zunset _ble_init_(version|arg|exit|command)\bZd
       \Zreadonly -f unsetZd
       \Zunset -f builtinZd
@@ -1372,13 +1384,13 @@ function sub:scan {
       \Z"\$__ble_proc" "\$__ble_name" unsetZd
       g'
   sub:scan/builtin 'unalias' |
-    sed -E 'h;s/'"$esc"'//g;s/^[^:]*:[0-9]+:[[:space:]]*//
+    sed -E 'h;s/'"$_make_rex_escseq"'//g;s/^[^:]*:[0-9]+:[[:space:]]*//
       \Zbuiltins1=\(.* unalias .*\)Zd
       g'
 
   #sub:scan/assign
   sub:scan/builtin trap |
-    sed -E 'h;s/'"$esc"'//g;s/^[^:]*:[0-9]+:[[:space:]]*//
+    sed -E 'h;s/'"$_make_rex_escseq"'//g;s/^[^:]*:[0-9]+:[[:space:]]*//
       \Z_ble_trap_handler="trap -- '\''\$\{_ble_trap_handler//\$q/\$Q}'\'' \$nZd
       \Zline = "bind"Zd
       \Ztrap_command=["'\'']trap -- Zd
@@ -1394,6 +1406,7 @@ function sub:scan {
   sub:scan/check-todo-mark
   sub:scan/bash300bug
   sub:scan/bash301bug-array-element-length
+  sub:scan/bash404-no-argument-return
   sub:scan/bash501-arith-base
   sub:scan/bash502-patsub_replacement
   sub:scan/gawk402bug-regex-check
diff --git a/memo/D1405.extract-man.sh b/memo/D1405.extract-man.sh
index b418de4b..162055c8 100755
--- a/memo/D1405.extract-man.sh
+++ b/memo/D1405.extract-man.sh
@@ -13,16 +13,16 @@ function ble/complete/mandb/search-file {
   local command=$1
 
   # Try "man -w" first
-  ble/complete/mandb/search-file/.check "$(man -w "$command" 2>/dev/null)" && return
+  ble/complete/mandb/search-file/.check "$(man -w "$command" 2>/dev/null)" && return 0
 
   local manpath=${MANPATH:-/usr/share/man:/usr/local/share/man:/usr/local/man}
   ble/string#split manpath : "$manpath"
   local path
   for path in "${manpath[@]}"; do
-    ble/complete/mandb/search-file/.check "$path/man1/$man.1.gz" && return
-    ble/complete/mandb/search-file/.check "$path/man1/$man.1" && return
-    ble/complete/mandb/search-file/.check "$path/man1/$man.8.gz" && return
-    ble/complete/mandb/search-file/.check "$path/man1/$man.8" && return
+    ble/complete/mandb/search-file/.check "$path/man1/$man.1.gz" && return 0
+    ble/complete/mandb/search-file/.check "$path/man1/$man.1" && return 0
+    ble/complete/mandb/search-file/.check "$path/man1/$man.8.gz" && return 0
+    ble/complete/mandb/search-file/.check "$path/man1/$man.8" && return 0
   done
   return 1
 }
diff --git a/memo/D1589-ConvertAirlineThemes.sh b/memo/D1589-ConvertAirlineThemes.sh
index b111e009..b50846ac 100644
--- a/memo/D1589-ConvertAirlineThemes.sh
+++ b/memo/D1589-ConvertAirlineThemes.sh
@@ -47,16 +47,16 @@ function face {
   # check mode
   case ${mode%_modified} in
   (normal|insert|replace|visual|commandline|inactive) ;;
-  (accents|tabline|ctrlp|terminal) return ;;
-  (*_paste|insert_replace|normal_error|insert_error) return ;;
+  (accents|tabline|ctrlp|terminal) return 0 ;;
+  (*_paste|insert_replace|normal_error|insert_error) return 0 ;;
   (*) ble/util/print "$theme: Unknown mode '$mode'" >&2
   esac
 
   # check face
   case $face in
   (airline_[abcxyz]|airline_error|airline_term|airline_warning) ;;
-  (airline_*_to_airline_*) return ;;
-  (airline_file) return ;; # ?????? itchyny/landscape.vim で使用
+  (airline_*_to_airline_*) return 0 ;;
+  (airline_file) return 0 ;; # ?????? itchyny/landscape.vim で使用
   (*) ble/util/print "$theme: Unknown face type '$face'" >&2
   esac
 
diff --git a/memo/D1645.check-c2w-table.sh b/memo/D1645.check-c2w-table.sh
index a54502e8..82a85cca 100755
--- a/memo/D1645.check-c2w-table.sh
+++ b/memo/D1645.check-c2w-table.sh
@@ -19,7 +19,7 @@ function dump {
 function c2w.binary {
   local c=$1
   ret=${_ble_unicode_EastAsianWidth_c2w[c]}
-  [[ $ret ]] && return
+  [[ $ret ]] && return 0
 
   local l u m
   ((l=0,u=${#_ble_unicode_EastAsianWidth_c2w_ranges[@]}-1))
@@ -38,7 +38,7 @@ function c2w.binary {
 function c2w.bindex {
   local c=$1
   ret=${_ble_unicode_EastAsianWidth_c2w[c]}
-  [[ $ret ]] && return
+  [[ $ret ]] && return 0
 
   ret=${_ble_unicode_EastAsianWidth_c2w_index[c<0x20000?c>>8:((c>>12)-32+512)]}
   if [[ $ret == *:* ]]; then
diff --git a/memo/D1782.test.sh b/memo/D1782.test.sh
index 9156552a..5be691be 100644
--- a/memo/D1782.test.sh
+++ b/memo/D1782.test.sh
@@ -5,7 +5,7 @@ flag=
 shopt -s extdebug
 
 function set_exit {
-  return $1
+  return "$1"
 }
 function set_trap {
   # DEBUG trap の中で trap や return を実行しても "現在のコマンド" は
@@ -20,7 +20,7 @@ function set_trap {
   # Note: continue や return の前に指定した終了ステータスは DEBUG trap
   # (extdebug) の振る舞いには関係ない。
   #
-  #trap '[[ $flag == 1 ]] && { echo "cmd:$FUNCNAME/$BASH_COMMAND"; set_exit 2; return; }' DEBUG
+  #trap '[[ $flag == 1 ]] && { echo "cmd:$FUNCNAME/$BASH_COMMAND"; set_exit 2; return 2; }' DEBUG
 
   trap '[[ $flag == 1 ]] && { echo "cmd:$FUNCNAME/$BASH_COMMAND"; shopt -s extdebug; set_exit 2; }' DEBUG
 }
diff --git a/note.txt b/note.txt
index e0128cf3..33428be4 100644
--- a/note.txt
+++ b/note.txt
@@ -1935,12 +1935,7 @@ bash_tips
   - todo 項目の整理
   - leakvars
   - keymap の移動 (これは別 commit にする?)
-
-2023-02-14
-
-  * no-argument return がまたある。make scan でチェックするべき。
-
-    $ grc 'return[[:space:]]*($|[;|&])'
+  - make_command.sh の整理 (scan 分離, char_width 分離)
 
 2023-02-12
 
@@ -6657,6 +6652,10 @@ bash_tips
 
 2023-02-14
 
+  * make: no-argument return がまたある。make scan でチェックするべき [#D1970]
+
+    $ grc 'return[[:space:]]*($|[;|&])'
+
   * histdb: git info 等追加情報を user の指定で記録できる様にする [#D1969]
     → "bleopt histdb_remarks" として実装した。
 
diff --git a/src/canvas.sh b/src/canvas.sh
index 36ebee46..dc6611fe 100644
--- a/src/canvas.sh
+++ b/src/canvas.sh
@@ -1391,7 +1391,7 @@ function ble/canvas/trace/.put-atomic.draw {
 }
 function ble/canvas/trace/.put-ascii.draw {
   local value=$1 w=${#1}
-  [[ $value ]] || return
+  [[ $value ]] || return 0
 
   if [[ $flag_clip ]]; then
     local xL=$x xR=$((x+w))
@@ -2898,14 +2898,14 @@ function ble/canvas/goto.draw {
 _ble_canvas_excursion_x=
 _ble_canvas_excursion_y=
 function ble/canvas/excursion-start.draw {
-  [[ $_ble_canvas_excursion ]] && return
+  [[ $_ble_canvas_excursion ]] && return 1
   _ble_canvas_excursion=1
   _ble_canvas_excursion_x=$_ble_canvas_x
   _ble_canvas_excursion_y=$_ble_canvas_y
   ble/canvas/put.draw "$_ble_term_sc"
 }
 function ble/canvas/excursion-end.draw {
-  [[ $_ble_canvas_excursion ]] || return
+  [[ $_ble_canvas_excursion ]] || return 1
   _ble_canvas_excursion=
   ble/canvas/put.draw "$_ble_term_rc"
   _ble_canvas_x=$_ble_canvas_excursion_x
diff --git a/src/decode.sh b/src/decode.sh
index c7127b2c..506eafe2 100644
--- a/src/decode.sh
+++ b/src/decode.sh
@@ -322,24 +322,24 @@ function ble-decode-kbd {
   case $spec in
   (keys:*)
     ret="${spec#*:}"
-    return ;;
+    return 0 ;;
   (chars:*)
     local chars
     ble/string#split-words chars "${spec#*:}"
     ble/decode/cmap/decode-chars "${ret[@]}"
     ret="${keys[*]}"
-    return ;;
+    return 0 ;;
   (keyseq:*) # i.e. untranslated keyseq
     local keys
     ble/util/keyseq2chars "${spec#*:}"
     ble/decode/cmap/decode-chars "${ret[@]}"
     ret="${keys[*]}"
-    return ;;
+    return 0 ;;
   (raw:*) # i.e. translated keyseq
     ble/util/s2chars "${spec#*:}"
     ble/decode/cmap/decode-chars "${ret[@]}"
     ret="${keys[*]}"
-    return ;;
+    return 0 ;;
   (kspecs:*)
     spec=${spec#*:} ;;
   esac
diff --git a/src/edit.sh b/src/edit.sh
index 91add8fe..0656e4e0 100644
--- a/src/edit.sh
+++ b/src/edit.sh
@@ -1268,10 +1268,11 @@ function ble/prompt/.get-keymap-for-current-mode {
   keymap=$_ble_decode_keymap
   local index=${#_ble_decode_keymap_stack[@]}
   while :; do
-    case $keymap in (vi_?map|emacs) return ;; esac
+    case $keymap in (vi_?map|emacs) return 0 ;; esac
     ((--index<0)) && break
     keymap=${_ble_decode_keymap_stack[index]}
   done
+  return 1
 }
 
 function ble/prompt/.uses-builtin-prompt-expansion {
@@ -6874,7 +6875,7 @@ function ble/widget/.insert-newline/trim-prompt {
   local ps1f=$bleopt_prompt_ps1_final
   local ps1t=$bleopt_prompt_ps1_transient
   if [[ ! $ps1f && :$ps1t: == *:trim:* ]]; then
-    [[ :$ps1t: == *:same-dir:* && $PWD != $_ble_prompt_trim_opwd ]] && return
+    [[ :$ps1t: == *:same-dir:* && $PWD != $_ble_prompt_trim_opwd ]] && return 0
     local y=${_ble_prompt_ps1_data[4]}
     if ((y)); then
       ble/canvas/panel#goto.draw "$_ble_textarea_panel" 0 0
diff --git a/src/util.hook.sh b/src/util.hook.sh
index 7f24ab0c..e9f28ff6 100644
--- a/src/util.hook.sh
+++ b/src/util.hook.sh
@@ -6,7 +6,7 @@
 ## @fn blehook/.print
 ##   @var[in] flags
 function blehook/.print {
-  (($#)) || return
+  (($#)) || return 0
 
   local out= q=\' Q="'\''" nl=$'\n'
   local sgr0= sgr1= sgr2= sgr3=
diff --git a/src/util.sh b/src/util.sh
index 09affc98..8c04ffb4 100644
--- a/src/util.sh
+++ b/src/util.sh
@@ -1198,7 +1198,7 @@ else
   function ble/string#quote-command {
     if (($#<=1)); then
       ret=$1
-      return
+      return 0
     fi
     local q=\' Q="'\''" IFS=$_ble_term_IFS
     ret=("${@:2}")
@@ -1228,14 +1228,14 @@ function ble/string#quote-word {
   if [[ ! $ret ]]; then
     [[ :$opts: == *:quote-empty:* ]] &&
       ret=$sgrq\'\'$sgr0
-    return
+    return 0
   fi
 
   local chars=$'\a\b\e\f\n\r\t\v'
   if [[ $ret == *["$chars"]* ]]; then
     ble/string#escape-for-bash-escape-string "$ret"
     ret=$sgrq\$\'$ret\'$sgr0
-    return
+    return 0
   fi
 
   local chars=$_ble_term_IFS'"`$\<>()|&;*?[]!^=:{,}#~' q=\'
@@ -5832,7 +5832,7 @@ _ble_term_TERM_done=
 function ble/term/DA2/initialize-term {
   local depth=$1
   local DA2R=${_ble_term_DA2R[depth]}
-  local rex='^[0-9]*(;[0-9]*)*$'; [[ $DA2R =~ $rex ]] || return
+  local rex='^[0-9]*(;[0-9]*)*$'; [[ $DA2R =~ $rex ]] || return 1
   local da2r
   ble/string#split da2r ';' "$DA2R"
   da2r=("${da2r[@]/#/10#0}") # 0で始まっていても10進数で解釈; WA #D1570 checked (is-array)
@@ -5915,7 +5915,7 @@ function ble/term/DA2/initialize-term {
       ((354<=version&&version<2000))
     else
       false
-    fi && { _ble_term_TERM[depth]=xterm:$version; return; }
+    fi && { _ble_term_TERM[depth]=xterm:$version; return 0; }
   fi
 
   _ble_term_TERM[depth]=unknown:-