Avoid shadowing variables in some Eshell command forms

* lisp/eshell/esh-cmd.el (eshell-rewrite-for-command): Make
'for-items' an uninterned symbol.
(eshell-as-subcommand): Correct docstring.
(eshell-do-command-to-value): Mark obsolete.
(eshell-command-to-value): Move binding of 'value' outside of the
macro's result, and remove call to 'eshell-do-command-to-value'.

* test/lisp/eshell/esh-cmd-tests.el
(esh-cmd-test/subcommand-shadow-value)
(esh-cmd-test/for-loop-for-items-shadow): New tests.
(esh-cmd-test/for-name-loop, esh-cmd-test/for-name-shadow-loop):
Rename to...
(esh-cmd-test/for-loop-name, esh-cmd-test/for-loop-name-shadow):
... these.

1 files changed, 16 insertions, 2 deletions

diff --git a/test/lisp/eshell/esh-cmd-tests.el b/test/lisp/eshell/esh-cmd-tests.el
index 94763954622..a7208eb3a0b 100644
--- a/test/lisp/eshell/esh-cmd-tests.el
+++ b/test/lisp/eshell/esh-cmd-tests.el
@@ -73,6 +73,13 @@ Test that trailing arguments outside the subcommand are ignored.
 e.g. \"{(+ 1 2)} 3\" => 3"
   (eshell-command-result-equal "{(+ 1 2)} 3" 3))
 
+(ert-deftest esh-cmd-test/subcommand-shadow-value ()
+  "Test that the variable `value' isn't shadowed inside subcommands."
+  (with-temp-eshell
+   (with-no-warnings (setq-local value "hello"))
+   (eshell-match-command-output "echo ${echo $value}"
+                                "hello\n")))
+
 (ert-deftest esh-cmd-test/let-rebinds-after-defer ()
   "Test that let-bound values are properly updated after `eshell-defer'.
 When inside a `let' block in an Eshell command form, we need to
@@ -151,13 +158,13 @@ bug#59469."
    (eshell-match-command-output "for i in 1 2 (list 3 4) { echo $i }"
                                 "1\n2\n3\n4\n")))
 
-(ert-deftest esh-cmd-test/for-name-loop () ; bug#15231
+(ert-deftest esh-cmd-test/for-loop-name () ; bug#15231
   "Test invocation of a for loop using `name'."
   (let ((process-environment (cons "name" process-environment)))
     (eshell-command-result-equal "for name in 3 { echo $name }"
                                  3)))
 
-(ert-deftest esh-cmd-test/for-name-shadow-loop () ; bug#15372
+(ert-deftest esh-cmd-test/for-loop-name-shadow () ; bug#15372
   "Test invocation of a for loop using an env-var."
   (let ((process-environment (cons "name=env-value" process-environment)))
     (with-temp-eshell
@@ -165,6 +172,13 @@ bug#59469."
       "echo $name; for name in 3 { echo $name }; echo $name"
       "env-value\n3\nenv-value\n"))))
 
+(ert-deftest esh-cmd-test/for-loop-for-items-shadow ()
+  "Test that the variable `for-items' isn't shadowed inside for loops."
+  (with-temp-eshell
+   (with-no-warnings (setq-local for-items "hello"))
+   (eshell-match-command-output "for i in 1 { echo $for-items }"
+                                "hello\n")))
+
 (ert-deftest esh-cmd-test/for-loop-pipe ()
   "Test invocation of a for loop piped to another command."
   (skip-unless (executable-find "rev"))