merge revision(s) 62607: [Backport #14557]

	file.c: realpath on special symlink

	* file.c (realpath_rec): fallback to symlink path when it is
	  accessible but the link target is not actual entry on file
	  systems.  [ruby-dev:50487] [Bug #14557]

git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/branches/ruby_2_4@62903 b2dd03c8-39d4-4d8f-98ff-823fe69b080e

3 files changed, 22 insertions, 8 deletions

diff --git a/file.c b/file.c
index 0e67654da2..f321b57f08 100644
--- a/file.c
+++ b/file.c
@@ -3778,7 +3778,7 @@ enum rb_realpath_mode {
 };
 
 static int
-realpath_rec(long *prefixlenp, VALUE *resolvedp, const char *unresolved,
+realpath_rec(long *prefixlenp, VALUE *resolvedp, const char *unresolved, VALUE fallback,
 	     VALUE loopcheck, enum rb_realpath_mode mode, int last)
 {
     const char *pend = unresolved + strlen(unresolved);
@@ -3841,6 +3841,12 @@ realpath_rec(long *prefixlenp, VALUE *resolvedp, const char *unresolved,
 #endif
                 if (ret == -1) {
 		    int e = errno;
+		    if (e == ENOENT && !NIL_P(fallback)) {
+			if (rb_stat(fallback, &sbuf) == 0) {
+			    rb_str_replace(*resolvedp, fallback);
+			    return 0;
+			}
+		    }
 		    if (mode == RB_REALPATH_CHECK) return -1;
 		    if (e == ENOENT) {
 			if (mode == RB_REALPATH_STRICT || !last || *unresolved_firstsep)
@@ -3872,7 +3878,7 @@ realpath_rec(long *prefixlenp, VALUE *resolvedp, const char *unresolved,
 			*resolvedp = link;
 			*prefixlenp = link_prefixlen;
 		    }
-		    if (realpath_rec(prefixlenp, resolvedp, link_names,
+		    if (realpath_rec(prefixlenp, resolvedp, link_names, testpath,
 				     loopcheck, mode, !*unresolved_firstsep))
 			return -1;
 		    RB_GC_GUARD(link_orig);
@@ -3960,14 +3966,14 @@ rb_check_realpath_internal(VALUE basedir, VALUE path, enum rb_realpath_mode mode
 
     loopcheck = rb_hash_new();
     if (curdir_names) {
-	if (realpath_rec(&prefixlen, &resolved, curdir_names, loopcheck, mode, 0))
+	if (realpath_rec(&prefixlen, &resolved, curdir_names, Qnil, loopcheck, mode, 0))
 	    return Qnil;
     }
     if (basedir_names) {
-	if (realpath_rec(&prefixlen, &resolved, basedir_names, loopcheck, mode, 0))
+	if (realpath_rec(&prefixlen, &resolved, basedir_names, Qnil, loopcheck, mode, 0))
 	    return Qnil;
     }
-    if (realpath_rec(&prefixlen, &resolved, path_names, loopcheck, mode, 1))
+    if (realpath_rec(&prefixlen, &resolved, path_names, Qnil, loopcheck, mode, 1))
 	return Qnil;
 
     if (origenc != enc && rb_enc_str_asciionly_p(resolved))
diff --git a/test/ruby/test_file.rb b/test/ruby/test_file.rb
index 58a4240391..d0d6a0ebe2 100644
--- a/test/ruby/test_file.rb
+++ b/test/ruby/test_file.rb
@@ -284,6 +284,14 @@ class TestFile < Test::Unit::TestCase
     }
   end
 
+  def test_realpath_special_symlink
+    IO.pipe do |r, w|
+      if File.pipe?(path = "/dev/fd/#{r.fileno}")
+        assert_file.identical?(File.realpath(path), path)
+      end
+    end
+  end
+
   def test_realdirpath
     Dir.mktmpdir('rubytest-realdirpath') {|tmpdir|
       realdir = File.realpath(tmpdir)
diff --git a/version.h b/version.h
index 82cdb46aa8..1455401a54 100644
--- a/version.h
+++ b/version.h
@@ -1,10 +1,10 @@
 #define RUBY_VERSION "2.4.4"
-#define RUBY_RELEASE_DATE "2018-03-22"
-#define RUBY_PATCHLEVEL 282
+#define RUBY_RELEASE_DATE "2018-03-23"
+#define RUBY_PATCHLEVEL 283
 
 #define RUBY_RELEASE_YEAR 2018
 #define RUBY_RELEASE_MONTH 3
-#define RUBY_RELEASE_DAY 22
+#define RUBY_RELEASE_DAY 23
 
 #include "ruby/version.h"