em-extpipe: Catch eshell-incomplete thrown while parsing

* lisp/eshell/em-extpipe.el (em-extpipe--or-with-catch): New macro.
(eshell-parse-external-pipeline): Use new macro to treat
`eshell-incomplete' as a failure of the parse function to move us
forward (Bug#54603).  Thanks to Jim Porter <jporterbugs@gmail.com> for
the report and for help isolating the problem.

* test/lisp/eshell/eshell-tests.el
(eshell-test/lisp-command-with-quote): New test for Bug#54603, thanks
to Jim Porter <jporterbugs@gmail.com> (bug#54603).

1 files changed, 4 insertions, 0 deletions

diff --git a/test/lisp/eshell/eshell-tests.el b/test/lisp/eshell/eshell-tests.el
index e31db07c619..1e303f70e5f 100644
--- a/test/lisp/eshell/eshell-tests.el
+++ b/test/lisp/eshell/eshell-tests.el
@@ -44,6 +44,10 @@
   "Test `eshell-command-result' with an elisp command."
   (should (equal (eshell-test-command-result "(+ 1 2)") 3)))
 
+(ert-deftest eshell-test/lisp-command-with-quote ()
+  "Test `eshell-command-result' with an elisp command containing a quote."
+  (should (equal (eshell-test-command-result "(eq 'foo nil)") nil)))
+
 (ert-deftest eshell-test/for-loop ()
   "Test `eshell-command-result' with a for loop.."
   (let ((process-environment (cons "foo" process-environment)))