Allow splitting strings in Eshell expansions with "plain" strings

Since '$var[hello 0]' doesn't make sense when 'var' is a string, the
previous restriction was unnecessary.

* lisp/eshell/esh-var.el (Commentary): Update documentation.
(eshell-apply-indices): Allow "plain" strings to split strings.

* test/lisp/eshell/esh-var-test.el
(esh-var-test/interp-var-string-split-indices)
(esh-var-test/quoted-interp-var-string-split-indices): Update tests.

* doc/misc/eshell.texi (Dollars expansion): Update documentation.

1 files changed, 12 insertions, 0 deletions

diff --git a/test/lisp/eshell/esh-var-tests.el b/test/lisp/eshell/esh-var-tests.el
index e679174939b..d09dd614de8 100644
--- a/test/lisp/eshell/esh-var-tests.el
+++ b/test/lisp/eshell/esh-var-tests.el
@@ -84,6 +84,11 @@
     (should (equal (eshell-test-command-result "echo $eshell-test-value[: 0]")
                    "zero"))
     (should (equal (eshell-test-command-result "echo $eshell-test-value[: 0 2]")
+                   '("zero" "two"))))
+  (let ((eshell-test-value "zeroXoneXtwoXthreeXfour"))
+    (should (equal (eshell-test-command-result "echo $eshell-test-value[X 0]")
+                   "zero"))
+    (should (equal (eshell-test-command-result "echo $eshell-test-value[X 0 2]")
                    '("zero" "two")))))
 
 (ert-deftest esh-var-test/interp-var-regexp-split-indices ()
@@ -216,6 +221,13 @@ inside double-quotes"
                    "zero"))
     (should (equal (eshell-test-command-result
                     "echo \"$eshell-test-value[: 0 2]\"")
+                   '("zero" "two"))))
+  (let ((eshell-test-value "zeroXoneXtwoXthreeXfour"))
+    (should (equal (eshell-test-command-result
+                    "echo \"$eshell-test-value[X 0]\"")
+                   "zero"))
+    (should (equal (eshell-test-command-result
+                    "echo \"$eshell-test-value[X 0 2]\"")
                    '("zero" "two")))))
 
 (ert-deftest esh-var-test/quoted-interp-var-regexp-split-indices ()