Add support for untaring of GNU tar files.

git-svn-id: https://svn.apache.org/repos/asf/ant/core/trunk@268568 13f79535-47bb-0310-9956-ffa450edef68

src/main/org/apache/tools/tar/TarEntry.java

@@ -454,7 +454,18 @@ public class TarEntry implements TarConstants {
     public void setSize(long size) {
         this.size = size;
     }   
+
         
+    /**
+     * Indicate if this entry is a GNU long name block
+     *
+     * @return true if this is a long name extension provided by GNU tar
+     */
+    public boolean isGNULongNameEntry() {
+        return linkFlag == LF_GNUTYPE_LONGNAME &&
+               name.toString().equals(GNU_LONGLINK);
+    }               
+
     /** 
      * Return whether or not this entry represents a directory.
      *  

src/main/org/apache/tools/tar/TarInputStream.java

@@ -286,6 +286,18 @@ public class TarInputStream extends FilterInputStream {
             this.entrySize = (int) this.currEntry.getSize();
         } 
 
+        if (this.currEntry != null && this.currEntry.isGNULongNameEntry()) {
+            // read in the name
+            StringBuffer longName = new StringBuffer();
+            byte[] buffer = new byte[256];
+            int length = 0;
+            while ((length = read(buffer)) >= 0) {
+                longName.append(new String(buffer, 0, length));
+            }
+            getNextEntry();
+            this.currEntry.setName(longName.toString());
+        }
+
         return this.currEntry;
     }