From: Noam Postavsky <npostavs@gmail.com>
Date: Sat, 2 Jun 2018 20:22:17 +0000 (-0400)
Subject: Fix off by one error in python-mode assertion (Bug#30964)
X-Git-Tag: emacs-27.0.90~4825
X-Git-Url: http://git.eshelyaron.com/gitweb/?a=commitdiff_plain;h=05345babc988060cca540770599282102c34f2a7;p=emacs.git

Fix off by one error in python-mode assertion (Bug#30964)

* lisp/progmodes/python.el (python-nav-end-of-statement): Don't assert
that string-start is strictly greater than last-string-end, because
the string end is a position outside of the string and may therefore
be the same as the following string's start.
* test/lisp/progmodes/python-tests.el (python-nav-end-of-statement-2):
New test.
---

diff --git a/lisp/progmodes/python.el b/lisp/progmodes/python.el
index 6f4a343310c..e39ff08739b 100644
--- a/lisp/progmodes/python.el
+++ b/lisp/progmodes/python.el
@@ -1518,7 +1518,7 @@ of the statement."
                        ;; are somehow out of whack.  This has been
                        ;; observed when using `syntax-ppss' during
                        ;; narrowing.
-                       (cl-assert (> string-start last-string-end)
+                       (cl-assert (>= string-start last-string-end)
                                   :show-args
                                   "\
 Overlapping strings detected (start=%d, last-end=%d)")
diff --git a/test/lisp/progmodes/python-tests.el b/test/lisp/progmodes/python-tests.el
index 1c4d22d72fa..0b9f8484c10 100644
--- a/test/lisp/progmodes/python-tests.el
+++ b/test/lisp/progmodes/python-tests.el
@@ -2004,6 +2004,12 @@ string
                 (python-util-forward-comment -1)
                 (point))))))
 
+(ert-deftest python-nav-end-of-statement-2 ()
+  "Test the string overlap assertion (Bug#30964)."
+  (python-tests-with-temp-buffer
+   "'\n''\n"
+   (python-nav-end-of-statement)))
+
 (ert-deftest python-nav-forward-statement-1 ()
   (python-tests-with-temp-buffer
    "