Make ?\LF generate 10, not -1 (bug#55738)

The old -1 value was an artefact of the reader implementation.

* src/lread.c (read_escape): Remove the `stringp` argument; assume
character literal syntax.  Never return -1.
(read_string_literal): Handle string-specific escape semantics here
and simplify.
* test/src/lread-tests.el (lread-escaped-lf): New test.

1 files changed, 5 insertions, 0 deletions

diff --git a/test/src/lread-tests.el b/test/src/lread-tests.el
index 47351c1d116..99eec9d5487 100644
--- a/test/src/lread-tests.el
+++ b/test/src/lread-tests.el
@@ -317,4 +317,9 @@ literals (Bug#20852)."
   (should (equal (read-from-string "#_")
                  '(## . 2))))
 
+(ert-deftest lread-escaped-lf ()
+  ;; ?\LF should produce LF (only inside string literals do we ignore \LF).
+  (should (equal (read-from-string "?\\\n") '(?\n . 3)))
+  (should (equal (read-from-string "\"a\\\nb\"") '("ab" . 6))))
+
 ;;; lread-tests.el ends here