merge revision(s) bf1a6771f305ea286a3ae575676924551c03e857,c1463625555b061a2b94c3b6c5581730b482a285: [Backport #17012] [Backport #17014]

Fix non-numeric exclusive Range#minmax bug

	The implementation of Range#minmax added in d5c60214c4 causes the
	following incorrect behaviour:

	  ('a'...'c').minmax => ["a", ["a", "b"]]

	instead of

	  ('a'...'c').minmax => ["a", "b"]

	This is because the C implementation of Range#minmax (range_minmax)
	directly delegates to the C implementation of Range#min (range_min) and
	Range#max (range_max), without changing the execution context.

	Range#max's C implementation (range_max), when given a non-numeric
	exclusive range, delegates to super, which is meant to call
	Enumerable#max. However, because range_max is called directly by
	range_minmax, super calls Enumerable#minmax instead, causing the
	incorrect nesting.

	Perhaps it is possible to change the execution context in an optimized
	manner, but the simplest solution seems to be to just explicitly
	delegate from Range#minmax to Range#min and Range#max.

	Use static variables in Range#minmax

range.c

@@ -22,6 +22,8 @@ VALUE rb_cRange;
 static ID id_beg, id_end, id_excl;
 #define id_cmp idCmp
 #define id_succ idSucc
+#define id_min idMin
+#define id_max idMax
 
 static VALUE r_cover_p(VALUE, VALUE, VALUE, VALUE);
 
@@ -1236,7 +1238,10 @@ range_minmax(VALUE range)
     if (rb_block_given_p()) {
         return rb_call_super(0, NULL);
     }
-    return rb_assoc_new(range_min(0, NULL, range), range_max(0, NULL, range));
+    return rb_assoc_new(
+        rb_funcall(range, id_min, 0),
+        rb_funcall(range, id_max, 0)
+    );
 }
 
 int

test/ruby/test_range.rb

@@ -146,6 +146,9 @@ class TestRange < Test::Unit::TestCase
     assert_equal([nil, nil], (0...0).minmax)
 
     assert_equal([2, 1], (1..2).minmax{|a, b| b <=> a})
+
+    assert_equal(['a', 'c'], ('a'..'c').minmax)
+    assert_equal(['a', 'b'], ('a'...'c').minmax)
   end
 
   def test_initialize_twice

version.h

@@ -2,7 +2,7 @@
 # define RUBY_VERSION_MINOR RUBY_API_VERSION_MINOR
 #define RUBY_VERSION_TEENY 1
 #define RUBY_RELEASE_DATE RUBY_RELEASE_YEAR_STR"-"RUBY_RELEASE_MONTH_STR"-"RUBY_RELEASE_DAY_STR
-#define RUBY_PATCHLEVEL 96
+#define RUBY_PATCHLEVEL 97
 
 #define RUBY_RELEASE_YEAR 2020
 #define RUBY_RELEASE_MONTH 7