merge revision(s) 58561: [Backport #13540]

	parse.y: make shared string modifiable

	* parse.y (dedent_string): ensure that the string is modifiable,
	  not to set the length of shared string.
	  [ruby-core:80987] [Bug #13540]

git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/branches/ruby_2_4@59513 b2dd03c8-39d4-4d8f-98ff-823fe69b080e

3 files changed, 16 insertions, 2 deletions

diff --git a/parse.y b/parse.y
index 13823c42ee..9160fcc576 100644
--- a/parse.y
+++ b/parse.y
@@ -6529,6 +6529,11 @@ dedent_string(VALUE string, int width)
 	    break;
 	}
     }
+    if (!i) return 0;
+    rb_str_modify(string);
+    str = RSTRING_PTR(string);
+    if (RSTRING_LEN(string) != len)
+	rb_fatal("literal string changed: %+"PRIsVALUE, string);
     MEMMOVE(str, str + i, char, len - i);
     rb_str_set_len(string, len - i);
     return i;
@@ -6585,7 +6590,6 @@ parser_dedent_string(VALUE self, VALUE input, VALUE width)
 
     StringValue(input);
     wid = NUM2UINT(width);
-    rb_str_modify(input);
     col = dedent_string(input, wid);
     return INT2NUM(col);
 }
diff --git a/test/ruby/test_parse.rb b/test/ruby/test_parse.rb
index ebdb2451a7..18e7d8f87c 100644
--- a/test/ruby/test_parse.rb
+++ b/test/ruby/test_parse.rb
@@ -970,6 +970,16 @@ x = __ENCODING__
     assert_equal(-100, e.backtrace_locations.first.lineno, bug)
   end
 
+  def test_file_in_indented_heredoc
+    name = '[ruby-core:80987] [Bug #13540]' # long enough to be shared
+    assert_equal(name+"\n", eval("#{<<-"begin;"}\n#{<<-'end;'}", nil, name))
+    begin;
+      <<~HEREDOC
+        #{__FILE__}
+      HEREDOC
+    end;
+  end
+
 =begin
   def test_past_scope_variable
     assert_warning(/past scope/) {catch {|tag| eval("BEGIN{throw tag}; tap {a = 1}; a")}}
diff --git a/version.h b/version.h
index 879d6891a0..5fd749fada 100644
--- a/version.h
+++ b/version.h
@@ -1,6 +1,6 @@
 #define RUBY_VERSION "2.4.2"
 #define RUBY_RELEASE_DATE "2017-08-05"
-#define RUBY_PATCHLEVEL 176
+#define RUBY_PATCHLEVEL 177
 
 #define RUBY_RELEASE_YEAR 2017
 #define RUBY_RELEASE_MONTH 8