[#3953] Use java.nio for FileTest#symlink?

gerhardgruber · headius · commit 1bcf17174e00 · 2017-11-12T00:44:11.000-06:00
diff --git a/core/src/main/java/org/jruby/RubyFileTest.java b/core/src/main/java/org/jruby/RubyFileTest.java
@@ -36,6 +36,10 @@
 import java.io.File;
 import java.io.IOException;
 import java.io.InputStream;
+import java.nio.file.Files;
+import java.nio.file.LinkOption;
+import java.nio.file.Path;
+import java.nio.file.attribute.BasicFileAttributes;
 
 import jnr.posix.FileStat;
 import org.jruby.anno.JRubyMethod;
@@ -278,21 +282,23 @@ public static IRubyObject sticky_p(IRubyObject recv, IRubyObject filename) {
     @JRubyMethod(name = "symlink?", required = 1, module = true)
     public static RubyBoolean symlink_p(IRubyObject recv, IRubyObject filename) {
         Ruby runtime = recv.getRuntime();
-        IRubyObject oldExc = runtime.getGlobalVariables().get("$!"); // Save $!
-        
+
+        Path p = new File(filename.toString()).toPath();
+
         try {
             // Note: We can't use file.exists() to check whether the symlink
             // exists or not, because that method returns false for existing
             // but broken symlink. So, we try without the existence check,
             // but in the try-catch block.
             // MRI behavior: symlink? on broken symlink should return true.
-            FileStat stat = fileResource(filename).lstat();
+            BasicFileAttributes attrs = Files.readAttributes(p, BasicFileAttributes.class, LinkOption.NOFOLLOW_LINKS);
 
-            return runtime.newBoolean(stat != null && stat.isSymlink());
-        } catch (SecurityException re) {
+            return runtime.newBoolean(attrs != null && attrs.isSymbolicLink());
+        } catch (SecurityException se) {
+            return runtime.getFalse();
+        } catch (IOException ie) {
             return runtime.getFalse();
-        } catch (RaiseException re) {
-            runtime.getGlobalVariables().set("$!", oldExc); // Restore $!
+        } catch (UnsupportedOperationException uoe) {
             return runtime.getFalse();
         }
     }
diff --git a/core/src/main/ruby/jruby/kernel/file.rb b/core/src/main/ruby/jruby/kernel/file.rb
@@ -122,38 +122,6 @@ def self.symlink(target, link)
           0 # Comply with spec
         end
 
-        # Returns whether or not +file+ is a symlink.
-        #
-        def self.symlink?(file)
-          file = string_check(file)
-
-          return false if file =~ /^(classpath:|classloader:|uri:classloader|jar:)/ || !File.exist?(file)
-
-          file.slice!(5..-1) if file =~ /^file:/
-          wfile = file.wincode
-          attrib = GetFileAttributesW(wfile)
-
-          if attrib == INVALID_FILE_ATTRIBUTES
-            raise SystemCallError.new('GetFileAttributes', FFI.errno)
-          end
-
-          if attrib & FILE_ATTRIBUTE_REPARSE_POINT > 0
-            begin
-              find_data = WIN32_FIND_DATA.new
-              handle = FindFirstFileW(wfile, find_data)
-
-              if handle == INVALID_HANDLE_VALUE
-                raise SystemCallError.new('FindFirstFile', FFI.errno)
-              end
-
-              return true if find_data[:dwReserved0] == IO_REPARSE_TAG_SYMLINK
-            ensure
-              CloseHandle(handle)
-            end
-          end
-          false
-        end
-
         private
 
         # Simulate Ruby's string checking
