Add a new variable `inhibit-interaction'

* doc/lispref/elisp.texi (Top): Add a link.
* doc/lispref/errors.texi (Standard Errors): Mention the new error.

* doc/lispref/minibuf.texi (Minibuffers): Add a link.
(Inhibiting Interaction): New node.

* src/data.c (syms_of_data): Define the `inhibited-interaction' error.

* src/lisp.h: Export the barfing function.

* src/lread.c (Fread_char, Fread_event, Fread_char_exclusive):
Barf if inhibited.

* src/minibuf.c (barf_if_interaction_inhibited): New function.
(Fread_from_minibuffer, Fread_no_blanks_input): Barf if inhibited.
(syms_of_minibuf): Define the `inhibit-interaction' variable.

2 files changed, 21 insertions, 0 deletions

diff --git a/test/src/lread-tests.el b/test/src/lread-tests.el
index edf88214f97..f2a60bcf327 100644
--- a/test/src/lread-tests.el
+++ b/test/src/lread-tests.el
@@ -190,4 +190,10 @@ literals (Bug#20852)."
 (ert-deftest lread-circular-hash ()
   (should-error (read "#s(hash-table data #0=(#0# . #0#))")))
 
+(ert-deftest test-inhibit-interaction ()
+  (let ((inhibit-interaction t))
+    (should-error (read-char "foo: "))
+    (should-error (read-event "foo: "))
+    (should-error (read-char-exclusive "foo: "))))
+
 ;;; lread-tests.el ends here
diff --git a/test/src/minibuf-tests.el b/test/src/minibuf-tests.el
index b9cd255462d..28119fc999e 100644
--- a/test/src/minibuf-tests.el
+++ b/test/src/minibuf-tests.el
@@ -410,5 +410,20 @@
     (should (equal (try-completion "baz" '("bAz" "baz"))
                    (try-completion "baz" '("baz" "bAz"))))))
 
+(ert-deftest test-inhibit-interaction ()
+  (let ((inhibit-interaction t))
+    (should-error (read-from-minibuffer "foo: "))
+
+    (should-error (y-or-n-p "foo: "))
+    (should-error (yes-or-no-p "foo: "))
+    (should-error (read-blanks-no-input "foo: "))
+
+    ;; See that we get the expected error.
+    (should (eq (condition-case nil
+                    (read-from-minibuffer "foo: ")
+                  (inhibited-interaction 'inhibit)
+                  (error nil))
+                'inhibit))))
+
 
 ;;; minibuf-tests.el ends here