master 785a045b86: Ensure that the CAR of 'eshell-last-async-procs' always points to a process

[Lars Ingebrigtsen]

branch: master
commit 785a045b868e0aeef08858e86a9efe48311e8f48
Author: Jim Porter <jporterbugs@gmail.com>
Commit: Lars Ingebrigtsen <larsi@gnus.org>

    Ensure that the CAR of 'eshell-last-async-procs' always points to a process
    
    Previously, if a non-process was piped to a process, this could end up
    being nil, which isn't correct.  'eshell-last-async-procs' should just
    ignore non-process commands in a pipeline.
    
    * lisp/eshell/esh-cmd.el (eshell-do-pipelines): Set 'headproc'
    correctly.
    
    * test/lisp/eshell/eshell-tests.el (eshell-test/pipe-headproc): New test.
---
 lisp/eshell/esh-cmd.el           | 3 +--
 test/lisp/eshell/eshell-tests.el | 7 +++++++
 2 files changed, 8 insertions(+), 2 deletions(-)

diff --git a/lisp/eshell/esh-cmd.el b/lisp/eshell/esh-cmd.el
index e702de03a0..5819506cc0 100644
--- a/lisp/eshell/esh-cmd.el
+++ b/lisp/eshell/esh-cmd.el
@@ -800,8 +800,7 @@ This macro calls itself recursively, with NOTFIRST non-nil."
                      ((cdr pipeline) t)
                      (t (quote 'last)))))
           (let ((proc ,(car pipeline)))
-            ,(unless notfirst
-               '(setq headproc proc))
+            (setq headproc (or proc headproc))
             (setq tailproc (or tailproc proc))
             proc))))))
 
diff --git a/test/lisp/eshell/eshell-tests.el b/test/lisp/eshell/eshell-tests.el
index c5ca0a5485..d6ee1bdb17 100644
--- a/test/lisp/eshell/eshell-tests.el
+++ b/test/lisp/eshell/eshell-tests.el
@@ -123,6 +123,13 @@ e.g. \"{(+ 1 2)} 3\" => 3"
    (eshell-command-result-p "echo ${echo hi}-${*echo there}"
                             "hi-there\n")))
 
+(ert-deftest eshell-test/pipe-headproc ()
+  "Check that piping a non-process to a process command waits for the process"
+  (skip-unless (executable-find "cat"))
+  (with-temp-eshell
+   (eshell-command-result-p "echo hi | *cat"
+                            "hi")))
+
 (ert-deftest eshell-test/pipe-tailproc ()
   "Check that piping a process to a non-process command waits for the process"
   (skip-unless (executable-find "echo"))