Fixed several append issues:

- FileChannelImpl.truncate() should not attempt to seek (would throw an exception)
- FileDispatcherImpl.write() doesn't need to seek to EOF
- FileDispatcherImpl.truncate() can't use fd.setLength() to truncate on append FileStream, so we open the file again to truncate it
- NetFileSystemProvider.newFileChannel() should not set FileSystemRights.Write in append mode

2 files changed, 12 insertions, 4 deletions

diff --git a/openjdk/sun/nio/ch/FileChannelImpl.java b/openjdk/sun/nio/ch/FileChannelImpl.java
index 86049d69..160e1f54 100644
--- a/openjdk/sun/nio/ch/FileChannelImpl.java
+++ b/openjdk/sun/nio/ch/FileChannelImpl.java
@@ -343,6 +343,10 @@ public class FileChannelImpl
                 if (!isOpen())
                     return null;
 
+                // [IKVM] in append mode we're not allowed to seek backwards, but the atomic append will honor the new file size
+                if (append)
+                    return this;
+
                 // set position to size if greater than size
                 if (p > size)
                     p = size;
diff --git a/openjdk/sun/nio/ch/FileDispatcherImpl.java b/openjdk/sun/nio/ch/FileDispatcherImpl.java
index e8d4a55b..9d836dfd 100644
--- a/openjdk/sun/nio/ch/FileDispatcherImpl.java
+++ b/openjdk/sun/nio/ch/FileDispatcherImpl.java
@@ -56,9 +56,6 @@ class FileDispatcherImpl extends FileDispatcher
     }
 
     int write(FileDescriptor fd, byte[] buf, int offset, int length) throws IOException {
-        if (append) {
-            fd.seek(fd.length());
-        }
         fd.writeBytes(buf, offset, length);
         return length;
     }
@@ -129,7 +126,14 @@ class FileDispatcherImpl extends FileDispatcher
     }
 
     int truncate(FileDescriptor fd, long size) throws IOException {
-        fd.setLength(size);
+        if (append) {
+            // HACK in append mode we're not allowed to truncate, so we try to reopen the file and truncate that
+            try (FileOutputStream fos = new FileOutputStream(((FileStream)fd.getStream()).get_Name())) {
+                fos.getFD().setLength(size);
+            }
+        } else {
+            fd.setLength(size);
+        }
         return 0;
     }