Merge pull request ibmruntimes#154 from Danja-Papajani/path-file-1-in…

…ter-patch

Port PathFileObject.java from Java 11 z/OS

src/jdk.compiler/share/classes/com/sun/tools/javac/file/PathFileObject.java

@@ -23,8 +23,15 @@
  * questions.
  */
 
+/*
+ * ===========================================================================
+ * (c) Copyright IBM Corp. 2019, 2019 All Rights Reserved
+ * ===========================================================================
+ */
+
 package com.sun.tools.javac.file;
 
+import java.io.FileInputStream;
 import java.io.IOException;
 import java.io.InputStream;
 import java.io.InputStreamReader;
@@ -47,6 +54,7 @@
 
 import javax.lang.model.element.Modifier;
 import javax.lang.model.element.NestingKind;
+import java.lang.UnsupportedOperationException;
 import javax.tools.FileObject;
 import javax.tools.JavaFileObject;
 
@@ -458,7 +466,30 @@ public URI toUri() {
     @Override @DefinedBy(Api.COMPILER)
     public InputStream openInputStream() throws IOException {
         fileManager.updateLastUsedTime();
-        return Files.newInputStream(path);
+        if (System.getProperty("os.name").equals("z/OS")) {
+            // Files.newInputStream(path) creates a ChannelInputStream
+            // and this seems to do auto-conversion based on the tagged
+            // codepage (Enhanced ASCII support) on zOS. This causes
+            // issue when the '-encoding' option is set on javac command
+            // To stop this we will create the FileInputStream directly
+            InputStream is;
+            try {
+                // if the encoding is set on the command line then use
+                // a FileInputStream otherwise use the Files.newInputStream
+                if (fileManager.getRawEncodingName() != null) {
+                    is = new FileInputStream(path.toFile());
+                } else {
+                    is = Files.newInputStream(path);
+                }
+            } catch (UnsupportedOperationException usoe ) {
+                // Some Path objects do not support the toFile() operation
+                // so in this case we will revert to using the original method
+                is = Files.newInputStream(path);
+            }
+            return is;
+        } else {
+           return Files.newInputStream(path);
+        }
     }
 
     @Override @DefinedBy(Api.COMPILER)