diff --git a/lib/core-complete.sh b/lib/core-complete.sh
index 33c2ce59..60506e27 100644
--- a/lib/core-complete.sh
+++ b/lib/core-complete.sh
@@ -1405,7 +1405,9 @@ function ble/complete/source:argument/.progcomp {
   else
     ble/util/assign compdef 'complete -p -- "$compcmd" 2>/dev/null'
   fi
-  compdef=${compdef%"$compcmd"} # strip -I, -D, or command_name
+  # strip -I, -D, or command_name
+  # #D1579 bash-5.1 では空コマンドに限り '' と出力する様である。
+  compdef=${compdef%"${compcmd:-''}"}
   compdef=${compdef%' '}' '
 
   local comp_prog comp_func compoptions flag_noquote
diff --git a/lib/core-syntax.sh b/lib/core-syntax.sh
index e17011a5..52a0c06e 100644
--- a/lib/core-syntax.sh
+++ b/lib/core-syntax.sh
@@ -4581,9 +4581,18 @@ function ble/syntax/completion-context/.check-prefix/ctx:quote/.check-container-
 
   local wlen2=${nest[1]}; ((wlen2>=0)) || return
   local wbeg2=$((wlen2<0?wlen2:inest-wlen2))
-
   if ble/syntax:bash/simple-word/is-simple-or-open-simple "${text:wbeg2:index-wbeg2}"; then
-    ble/syntax/completion-context/.add argument "$wbeg2"
+    local wt=${nest[2]}
+    [[ ${_ble_syntax_bash_command_EndWtype[wt]} ]] &&
+      wt=${_ble_syntax_bash_command_EndWtype[wt]}
+    if ((wt==CTX_CMDI)); then
+      ble/syntax/completion-context/.add command "$wbeg2"
+    elif ((wt==CTX_ARGI||wt==CTX_ARGVI||wt==CTX_ARGEI||wt==CTX_FARGI2||wt==CTX_CARGI2)); then
+      ble/syntax/completion-context/.add argument "$wbeg2"
+    elif ((wt==CTX_CPATI)); then # case pattern の内部
+      #ble/syntax/completion-context/.add file "$wbeg2"
+      return
+    fi
   fi
 }