Support arbitrary Eshell arguments inside special references

* lisp/eshell/esh-arg.el (eshell-current-argument-plain): New variable.
(eshell-parse-special-reference): Use 'eshell-parse-arguments'.
(eshell-get-buffer): New function.
(eshell-insert-buffer-name): Properly quote the buffer name.

* lisp/eshell/esh-proc.el (eshell-read-process-name): Move to "Special
references" section.
(eshell-insert-process): Properly quote the process name.

* lisp/eshell/em-extpipe.el (eshell-parse-external-pipeline):
* lisp/eshell/esh-io.el (eshell-parse-redirection): Don't do anything
when 'eshell-argument-plain' is non-nil.

* test/lisp/eshell/esh-arg-tests.el
(esh-arg-test/special-reference/quoted)
(esh-arg-test/special-reference/var-expansion): New tests.
(esh-arg-test/special-reference/special): Rename to...
(esh-arg-test/special-reference/special-characters): ... this.

* test/lisp/eshell/em-extpipe-tests.el (em-extpipe-tests--deftest):
Properly quote the buffer name.
(em-extpipe-test-4, em-extpipe-test-7): Use 'eshell-get-buffer'.

2 files changed, 29 insertions, 4 deletions

diff --git a/test/lisp/eshell/em-extpipe-tests.el b/test/lisp/eshell/em-extpipe-tests.el
index bdffcd9b320..6984ec2de59 100644
--- a/test/lisp/eshell/em-extpipe-tests.el
+++ b/test/lisp/eshell/em-extpipe-tests.el
@@ -55,7 +55,9 @@
                              "temp\\([^>]\\|\\'\\)" temp
                              (string-replace
                               "#<buffer temp>"
-                              (concat "#<buffer " (buffer-name temp-buffer) ">")
+                              (format "#<buffer %s>"
+                                      (eshell-quote-argument
+                                       (buffer-name temp-buffer)))
                               input))))
                        ,@body)
                    (when (buffer-name temp-buffer)
@@ -110,7 +112,7 @@
    '(progn
       (ignore
        (eshell-set-output-handle 1 'overwrite
-                                 (get-buffer-create "temp")))
+                                 (eshell-get-buffer "temp")))
       (eshell-named-command "sh"
                             (list "-c" "echo \"bar\" | rev"))))
   (with-substitute-for-temp
@@ -133,7 +135,7 @@
    '(progn
       (ignore
        (eshell-set-output-handle 1 'overwrite
-                                 (get-buffer-create "quux")))
+                                 (eshell-get-buffer "quux")))
       (ignore
        (eshell-set-output-handle 1 'append
                                  (get-process "other")))
diff --git a/test/lisp/eshell/esh-arg-tests.el b/test/lisp/eshell/esh-arg-tests.el
index c883db3907f..0e07d107562 100644
--- a/test/lisp/eshell/esh-arg-tests.el
+++ b/test/lisp/eshell/esh-arg-tests.el
@@ -118,7 +118,30 @@ treated literally, as a backslash and a newline."
      (format "echo #<buffer %s>" (buffer-name))
      (current-buffer))))
 
-(ert-deftest esh-arg-test/special-reference/special ()
+(ert-deftest esh-arg-test/special-reference/quoted ()
+  "Test that '#<buffer \"foo bar\">' refers to the buffer \"foo bar\"."
+  (with-temp-buffer
+    (rename-buffer "foo bar" t)
+    (eshell-command-result-equal
+     (format "echo #<buffer \"%s\">" (buffer-name))
+     (current-buffer))
+    (eshell-command-result-equal
+     (format "echo #<buffer '%s'>" (buffer-name))
+     (current-buffer))))
+
+(ert-deftest esh-arg-test/special-reference/var-expansion ()
+  "Test that variable expansion inside special references works."
+  (with-temp-buffer
+    (rename-buffer "my-buffer" t)
+    (let ((eshell-test-value (buffer-name)))
+      (eshell-command-result-equal
+       "echo #<buffer $eshell-test-value>"
+       (current-buffer))
+      (eshell-command-result-equal
+       "echo #<buffer \"$eshell-test-value\">"
+       (current-buffer)))))
+
+(ert-deftest esh-arg-test/special-reference/special-characters ()
   "Test that \"#<...>\" works correctly when escaping special characters."
   (with-temp-buffer
     (rename-buffer "<my buffer>" t)