47873: Improve completion within dynamic directory names

ChangeLog

@@ -1,5 +1,10 @@
 2021-01-27  Peter Stephenson  <p.stephenson@samsung.com>
 
+	* 47873: Completion/Base/Core/_main_complete,
+	Completion/Zsh/Context/_subscript,
+	Functions/Chpwd/zsh_directory_name_cdr: Improve completion
+	within dynamic directory names ~[<here>].
+
 	* GammaFunction@vivaldi.net via Roman: 47744:
 	Src/Zle/zle_main.c: Fix vi-repeat-change when hooks are in use.
 

Completion/Base/Core/_main_complete

@@ -94,8 +94,18 @@ if [[ -z "$compstate[quote]" ]]; then
   if [[ -o equals ]] && compset -P 1 '='; then
     compstate[context]=equal
   elif [[ "$PREFIX" != */* && "$PREFIX[1]" = '~' ]]; then
-    compset -p 1
-    compstate[context]=tilde
+    if [[ "$PREFIX" = '~['[^\]]# ]]; then
+      # Inside ~[...] should be treated as a subscript.
+      compset -p 2
+      # To be consistent, we ignore all but the contents of the square
+      # brackets.
+      compset -S '\]*'
+      compstate[context]=subscript
+      [[ -n $_comps[-subscript-] ]] && $_comps[-subscript-] && return
+    else
+      compset -p 1
+      compstate[context]=tilde
+    fi
   fi
 fi
 

Completion/Zsh/Context/_subscript

@@ -1,6 +1,8 @@
 #compdef -subscript-
 
-local expl ind osuf=']' flags sep
+local expl ind osuf flags sep
+
+[[ $ISUFFIX = *\]* ]] || osuf=\]
 
 if [[ "$1" = -q ]]; then
   compquote osuf

Functions/Chpwd/zsh_directory_name_cdr

@@ -16,8 +16,10 @@ elif [[ $1 = c ]]; then
     typeset -a keys values
     values=(${${(f)"$(cdr -l)"}/ ##/:})
     keys=(${values%%:*})
+    local addsuffix
+    [[ $ISUFFIX = *\]* ]] || addsuffix='-S]'
     _describe -t dir-index 'recent directory index' \
-      values -V unsorted -S']'
+      values -V unsorted $addsuffix
     return
   fi
 fi