merge revision(s) 57187,57234: [Backport #13075]

	pack.c: avoid returning uninitialized String

	Fix unpacking with 'b', 'B', 'h' and 'H' format. Do not return an
	uninitialized String to Ruby before filling the content bytes.
	Fixes r11175 ("pack.c (pack_unpack): execute block if given with
	unpacked value instead of creating an array", 2006-10-15).
	[ruby-core:78841] [Bug #13075]
	test/ruby/test_pack.rb: fix test case added by r57187

	The test case for String#unpack added by r57187 is not properly testing
	because the String will be filled after the block invocation.
	[ruby-core:78841] [Bug #13075]

	Thanks to nagachika for pointing this out:

  http://d.hatena.ne.jp/nagachika/20161226/ruby_trunk_changes_57184_57194#r57187

git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/branches/ruby_2_4@57833 b2dd03c8-39d4-4d8f-98ff-823fe69b080e

3 files changed, 17 insertions, 5 deletions

diff --git a/pack.c b/pack.c
index a8339c7219..d275a286b0 100644
--- a/pack.c
+++ b/pack.c
@@ -1194,13 +1194,14 @@ pack_unpack_internal(VALUE str, VALUE fmt, int mode)
 		if (p[-1] == '*' || len > (send - s) * 8)
 		    len = (send - s) * 8;
 		bits = 0;
-		UNPACK_PUSH(bitstr = rb_usascii_str_new(0, len));
+		bitstr = rb_usascii_str_new(0, len);
 		t = RSTRING_PTR(bitstr);
 		for (i=0; i<len; i++) {
 		    if (i & 7) bits >>= 1;
 		    else bits = (unsigned char)*s++;
 		    *t++ = (bits & 1) ? '1' : '0';
 		}
+		UNPACK_PUSH(bitstr);
 	    }
 	    break;
 
@@ -1214,13 +1215,14 @@ pack_unpack_internal(VALUE str, VALUE fmt, int mode)
 		if (p[-1] == '*' || len > (send - s) * 8)
 		    len = (send - s) * 8;
 		bits = 0;
-		UNPACK_PUSH(bitstr = rb_usascii_str_new(0, len));
+		bitstr = rb_usascii_str_new(0, len);
 		t = RSTRING_PTR(bitstr);
 		for (i=0; i<len; i++) {
 		    if (i & 7) bits <<= 1;
 		    else bits = (unsigned char)*s++;
 		    *t++ = (bits & 128) ? '1' : '0';
 		}
+		UNPACK_PUSH(bitstr);
 	    }
 	    break;
 
@@ -1234,7 +1236,7 @@ pack_unpack_internal(VALUE str, VALUE fmt, int mode)
 		if (p[-1] == '*' || len > (send - s) * 2)
 		    len = (send - s) * 2;
 		bits = 0;
-		UNPACK_PUSH(bitstr = rb_usascii_str_new(0, len));
+		bitstr = rb_usascii_str_new(0, len);
 		t = RSTRING_PTR(bitstr);
 		for (i=0; i<len; i++) {
 		    if (i & 1)
@@ -1243,6 +1245,7 @@ pack_unpack_internal(VALUE str, VALUE fmt, int mode)
 			bits = (unsigned char)*s++;
 		    *t++ = hexdigits[bits & 15];
 		}
+		UNPACK_PUSH(bitstr);
 	    }
 	    break;
 
@@ -1256,7 +1259,7 @@ pack_unpack_internal(VALUE str, VALUE fmt, int mode)
 		if (p[-1] == '*' || len > (send - s) * 2)
 		    len = (send - s) * 2;
 		bits = 0;
-		UNPACK_PUSH(bitstr = rb_usascii_str_new(0, len));
+		bitstr = rb_usascii_str_new(0, len);
 		t = RSTRING_PTR(bitstr);
 		for (i=0; i<len; i++) {
 		    if (i & 1)
@@ -1265,6 +1268,7 @@ pack_unpack_internal(VALUE str, VALUE fmt, int mode)
 			bits = (unsigned char)*s++;
 		    *t++ = hexdigits[(bits >> 4) & 15];
 		}
+		UNPACK_PUSH(bitstr);
 	    }
 	    break;
 
diff --git a/test/ruby/test_pack.rb b/test/ruby/test_pack.rb
index e9267fab1c..6d2eecbc9f 100644
--- a/test/ruby/test_pack.rb
+++ b/test/ruby/test_pack.rb
@@ -838,10 +838,18 @@ EXPECTED
     assert_equal addr, [buf].pack('p')
   end
 
+  def test_unpack_with_block
+    ret = []; "ABCD".unpack("CCCC") {|v| ret << v }
+    assert_equal [65, 66, 67, 68], ret
+    ret = []; "A".unpack("B*") {|v| ret << v.dup }
+    assert_equal ["01000001"], ret
+  end
+
   def test_unpack1
     assert_equal 65, "A".unpack1("C")
     assert_equal 68, "ABCD".unpack1("x3C")
     assert_equal 0x3042, "\u{3042 3044 3046}".unpack1("U*")
     assert_equal "hogefuga", "aG9nZWZ1Z2E=".unpack1("m")
+    assert_equal "01000001", "A".unpack1("B*")
   end
 end
diff --git a/version.h b/version.h
index 6ebeaf7cbb..2297747a00 100644
--- a/version.h
+++ b/version.h
@@ -1,6 +1,6 @@
 #define RUBY_VERSION "2.4.0"
 #define RUBY_RELEASE_DATE "2017-03-11"
-#define RUBY_PATCHLEVEL 3
+#define RUBY_PATCHLEVEL 4
 
 #define RUBY_RELEASE_YEAR 2017
 #define RUBY_RELEASE_MONTH 3