merge revision(s) 62042,62044: [Backport #14380]

	hash.c: support key swapping in Hash#transform_keys!

	* hash.c (rb_hash_transform_keys_bang): support key swapping in
	  Hash#transform_keys!
	  [Bug #14380] [ruby-core:84951]

	* test/ruby/test_hash.rb (test_transform_keys_bang):
	  add assertions for this change

	Fix rubyspec against the change in Hash#transform_keys!

	[Bug #14380] [ruby-core:84951]

git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/branches/ruby_2_5@62889 b2dd03c8-39d4-4d8f-98ff-823fe69b080e

4 files changed, 22 insertions, 10 deletions

diff --git a/hash.c b/hash.c
index 285f6118b1..29b8289c98 100644
--- a/hash.c
+++ b/hash.c
@@ -1910,6 +1910,8 @@ rb_hash_transform_keys(VALUE hash)
     return result;
 }
 
+static VALUE rb_hash_flatten(int argc, VALUE *argv, VALUE hash);
+
 /*
  *  call-seq:
  *     hsh.transform_keys! {|key| block } -> hsh
@@ -1933,12 +1935,14 @@ rb_hash_transform_keys_bang(VALUE hash)
     RETURN_SIZED_ENUMERATOR(hash, 0, 0, hash_enum_size);
     rb_hash_modify_check(hash);
     if (RHASH(hash)->ntbl) {
-	long i;
-	VALUE keys = rb_hash_keys(hash);
-	for (i = 0; i < RARRAY_LEN(keys); ++i) {
-	    VALUE key = RARRAY_AREF(keys, i), new_key = rb_yield(key);
-	    rb_hash_aset(hash, new_key, rb_hash_delete(hash, key));
-	}
+        long i;
+        VALUE pairs = rb_hash_flatten(0, NULL, hash);
+        rb_hash_clear(hash);
+        for (i = 0; i < RARRAY_LEN(pairs); i += 2) {
+            VALUE key = RARRAY_AREF(pairs, i), new_key = rb_yield(key),
+                  val = RARRAY_AREF(pairs, i+1);
+            rb_hash_aset(hash, new_key, val);
+        }
     }
     return hash;
 }
diff --git a/spec/ruby/core/hash/transform_keys_spec.rb b/spec/ruby/core/hash/transform_keys_spec.rb
index 379638bd4b..cf42f17e51 100644
--- a/spec/ruby/core/hash/transform_keys_spec.rb
+++ b/spec/ruby/core/hash/transform_keys_spec.rb
@@ -60,9 +60,9 @@ ruby_version_is "2.5" do
       @hash.should == { 'a' => 1, 'b' => 2, 'c' => 3, 'd' => 4 }
     end
 
-    it "does not prevent conflicts between new keys and old ones" do
+    it "prevents conflicts between new keys and old ones" do
       @hash.transform_keys!(&:succ)
-      @hash.should == { e: 1 }
+      @hash.should == { b: 1, c: 2, d: 3, e: 4 }
     end
 
     it "partially modifies the contents if we broke from the block" do
@@ -70,7 +70,7 @@ ruby_version_is "2.5" do
         break if v == :c
         v.succ
       end
-      @hash.should == { c: 1, d: 4 }
+      @hash.should == { b: 1, c: 2 }
     end
 
     it "keeps later pair if new keys conflict" do
diff --git a/test/ruby/test_hash.rb b/test/ruby/test_hash.rb
index 4223aa8140..bdcf022668 100644
--- a/test/ruby/test_hash.rb
+++ b/test/ruby/test_hash.rb
@@ -1573,6 +1573,14 @@ class TestHash < Test::Unit::TestCase
 
     x.transform_keys!.with_index {|k, i| "#{k}.#{i}" }
     assert_equal(%w(a!.0 b!.1 c!.2), x.keys)
+
+    x = @cls[1 => :a, -1 => :b]
+    x.transform_keys! {|k| -k }
+    assert_equal([-1, :a, 1, :b], x.flatten)
+
+    x = @cls[true => :a, false => :b]
+    x.transform_keys! {|k| !k }
+    assert_equal([false, :a, true, :b], x.flatten)
   end
 
   def test_transform_values
diff --git a/version.h b/version.h
index b28c6461e2..28cff34c19 100644
--- a/version.h
+++ b/version.h
@@ -1,6 +1,6 @@
 #define RUBY_VERSION "2.5.0"
 #define RUBY_RELEASE_DATE "2018-03-20"
-#define RUBY_PATCHLEVEL 47
+#define RUBY_PATCHLEVEL 48
 
 #define RUBY_RELEASE_YEAR 2018
 #define RUBY_RELEASE_MONTH 3