Fix evaluation of asynchronous expansions in Eshell indices

Previously, this code passed the indices to a separate function, which
called 'eval' on them, but it should instead make an S-expr that
'eshell-do-eval' can evaluate (bug#60942).

* lisp/eshell/esh-var.el (eshell-eval-indices): Mark obsolete.
(eshell-prepare-indices): New function...
(eshell-parse-variable): ... use it.  Also, remove irrelevant comment.
(eshell-parse-variable-ref): Fix quoting in docstring.
(eshell-parse-indices): Fix typo in docstring.

* test/lisp/eshell/esh-var-tests.el
(esh-var-test/interp-var-indices-subcommand)
(esh-var-test/quoted-interp-var-indices-subcommand): New tests.

1 files changed, 9 insertions, 5 deletions

diff --git a/lisp/eshell/esh-var.el b/lisp/eshell/esh-var.el
index 27e68138aa2..83dd5cb50f5 100644
--- a/lisp/eshell/esh-var.el
+++ b/lisp/eshell/esh-var.el
@@ -467,9 +467,7 @@ process any indices that come after the variable reference."
 	  indices (and (not (eobp))
 		       (eq (char-after) ?\[)
 		       (eshell-parse-indices))
-          ;; This is an expression that will be evaluated by `eshell-do-eval',
-          ;; which only support let-binding of dynamically-scoped vars
-	  value `(let ((indices (eshell-eval-indices ',indices))) ,value))
+          value `(let ((indices ,(eshell-prepare-indices indices))) ,value))
     (when get-len
       (setq value `(length ,value)))
     (when eshell-current-quoted
@@ -496,7 +494,7 @@ Possible variable references are:
 
   NAME          an environment or Lisp variable value
   \"LONG-NAME\"   disambiguates the length of the name
-  `LONG-NAME'   as above
+  \\='LONG-NAME\\='   as above
   {COMMAND}     result of command is variable's value
   (LISP-FORM)   result of Lisp form is variable's value
   <COMMAND>     write the output of command to a temporary file;
@@ -591,7 +589,7 @@ Possible variable references are:
   "Parse and return a list of index-lists.
 
 For example, \"[0 1][2]\" becomes:
-  ((\"0\" \"1\") (\"2\")."
+  ((\"0\" \"1\") (\"2\"))."
   (let (indices)
     (while (eq (char-after) ?\[)
       (let ((end (eshell-find-delimiter ?\[ ?\])))
@@ -609,8 +607,14 @@ For example, \"[0 1][2]\" becomes:
 
 (defun eshell-eval-indices (indices)
   "Evaluate INDICES, a list of index-lists generated by `eshell-parse-indices'."
+  (declare (obsolete eshell-prepare-indices "30.1"))
   (mapcar (lambda (i) (mapcar #'eval i)) indices))
 
+(defun eshell-prepare-indices (indices)
+  "Prepare INDICES to be evaluated by Eshell.
+INDICES is a list of index-lists generated by `eshell-parse-indices'."
+  `(list ,@(mapcar (lambda (idx-list) (cons 'list idx-list)) indices)))
+
 (defun eshell-get-variable (name &optional indices quoted)
   "Get the value for the variable NAME.
 INDICES is a list of index-lists (see `eshell-parse-indices').