[elpa] externals/m-buffer 3702262fbc 092/115: m-buffer was not stateless at all!

[ELPA Syncer]

branch: externals/m-buffer
commit 3702262fbc7b4eaa625f99162eba8c46fb612c74
Author: Phillip Lord <phillip.lord@newcastle.ac.uk>
Commit: Phillip Lord <phillip.lord@newcastle.ac.uk>

    m-buffer was not stateless at all!
    
    A bug in m-buffer-match meant that the m-buffer-match-* functions was
    not at all stateless. The bug was caused because m-buffer-match saved
    all the various states before setting the current buffer.
---
 m-buffer.el           | 12 ++++++------
 test/m-buffer-test.el | 26 ++++++++++++++++++++++++++
 2 files changed, 32 insertions(+), 6 deletions(-)

diff --git a/m-buffer.el b/m-buffer.el
index dadd538c23..769e4e30b3 100644
--- a/m-buffer.el
+++ b/m-buffer.el
@@ -11,7 +11,7 @@
 
 ;; The contents of this file are subject to the GPL License, Version 3.0.
 
-;; Copyright (C) 2014, Phillip Lord, Newcastle University
+;; Copyright (C) 2014, 2015, Phillip Lord, Newcastle University
 
 ;; This program is free software: you can redistribute it and/or modify
 ;; it under the terms of the GNU General Public License as published by
@@ -139,11 +139,11 @@ NUMERIC -- Non-nil if we should return integers not 
markers."
 ;; this is all the global state that exists and that we are changing.
 
 ;; #+begin_src emacs-lisp
-  (save-match-data
-    (save-excursion
-      (save-restriction
-        (with-current-buffer
-            buffer
+  (with-current-buffer
+      buffer
+    (save-match-data
+      (save-excursion
+        (save-restriction
           (when widen (widen))
 ;; #+end_src
 
diff --git a/test/m-buffer-test.el b/test/m-buffer-test.el
index afe828374b..029f5a1c51 100644
--- a/test/m-buffer-test.el
+++ b/test/m-buffer-test.el
@@ -421,4 +421,30 @@ should not have moved."
      ))))
 
 
+(ert-deftest point-stationionary-with-current ()
+  "This test addresses a bug where m-buffer did not correctly
+protect global state when the buffer being operated on was not
+current -- in this case, a match could move point.
+
+The two clauses are identical, one changing the current buffer
+and one changing a buffer which is not current."
+  (should
+   (let ((out) (out-point))
+     (with-temp-buffer
+       (insert "one\ntwo\nthree\n")
+       (setq out (current-buffer))
+       (setq out-point (point))
+       (m-buffer-match-first-line out)
+       (= (point) out-point))))
+
+   (should
+    (let ((out) (out-point))
+      (with-temp-buffer
+        (insert "one\ntwo\nthree\n")
+        (setq out (current-buffer))
+        (setq out-point (point))
+        (with-temp-buffer
+          (m-buffer-match-first-line out))
+        (= (point) out-point)))))
+
 ;;; m-buffer-test.el ends here