Re: master 37940b3: min and max now return one of their arguments

[Paul Eggert <eggert@cs.ucla.edu>]

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Glenn Morris wrote:
> It seems that this change causes a bunch of tests to fail with
>
> (wrong-type-argument numberp #<marker in no buffer>)

Sorry about that. Apparently 'min' and 'max' converted any marker result to an 
integer. I changed them back to do that with the attached patch. This behavior 
is undocumented; I don't know whether it was intended, although it looks like 
some code relies on it now.

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From 79825fd06cfd7140c8d6e25db1c0fdc5a42f6098 Mon Sep 17 00:00:00 2001
From: Paul Eggert <eggert@cs.ucla.edu>
Date: Tue, 7 Mar 2017 21:23:08 -0800
Subject: [PATCH] min and max should not return markers

Problem reported by Glenn Morris in:
http://lists.gnu.org/archive/html/emacs-devel/2017-03/msg00147.html
* src/data.c (minmax_driver): Convert any marker result to an
integer, since some callers assume this.
* test/src/data-tests.el (data-tests-max, data-tests-min):
Test for this.
---
 src/data.c             | 4 ++--
 test/src/data-tests.el | 8 ++++++--
 2 files changed, 8 insertions(+), 4 deletions(-)

diff --git a/src/data.c b/src/data.c
index 29547d8..c480ed2 100644
--- a/src/data.c
+++ b/src/data.c
@@ -2972,9 +2972,9 @@ minmax_driver (ptrdiff_t nargs, Lisp_Object *args,
       if (argnum == 0 || !NILP (arithcompare (val, accum, comparison)))
 	accum = val;
       else if (FLOATP (accum) && isnan (XFLOAT_DATA (accum)))
-	break;
+	return accum;
     }
-  return accum;
+  return MARKERP (accum) ? make_number (marker_position (accum)) : accum;
 }
 
 DEFUN ("max", Fmax, Smax, 1, MANY, 0,
diff --git a/test/src/data-tests.el b/test/src/data-tests.el
index 70ffdab..67d00a7 100644
--- a/test/src/data-tests.el
+++ b/test/src/data-tests.el
@@ -88,7 +88,9 @@
   (should (= (1+ most-negative-fixnum)
              (max (float most-negative-fixnum) (1+ most-negative-fixnum))))
   (should (= 8 (apply #'max '(3 8 3))))
-  (should-error (max 9 8 'foo)))
+  (should-error (max 9 8 'foo))
+  (should-error (max (make-marker)))
+  (should (eql 1 (max (point-min-marker) 1))))
 
 (ert-deftest data-tests-min ()
   (should-error (min))
@@ -98,7 +100,9 @@
   (should (= most-positive-fixnum
              (min (+ 1.0 most-positive-fixnum) most-positive-fixnum)))
   (should (= 3 (apply #'min '(3 8 3))))
-  (should-error (min 9 8 'foo)))
+  (should-error (min 9 8 'foo))
+  (should-error (min (make-marker)))
+  (should (eql 1 (min (point-min-marker) 1))))
 
 ;; Bool vector tests.  Compactly represent bool vectors as hex
 ;; strings.
-- 
2.9.3