diff -r b52a38d4536c -r 189b26e3818f src/share/classes/com/sun/tools/javac/file/ZipFileIndex.java
--- a/src/share/classes/com/sun/tools/javac/file/ZipFileIndex.java	Fri Dec 21 08:45:43 2012 -0800
+++ b/src/share/classes/com/sun/tools/javac/file/ZipFileIndex.java	Fri Dec 21 15:27:55 2012 +0000
@@ -548,17 +548,15 @@
                 }
 
                 if (i >= 0) {
-                    zipDir = new byte[get4ByteLittleEndian(endbuf, i + 12) + 2];
-                    zipDir[0] = endbuf[i + 10];
-                    zipDir[1] = endbuf[i + 11];
+                    zipDir = new byte[get4ByteLittleEndian(endbuf, i + 12)];
                     int sz = get4ByteLittleEndian(endbuf, i + 16);
                     // a negative offset or the entries field indicates a
                     // potential zip64 archive
-                    if (sz < 0 || get2ByteLittleEndian(zipDir, 0) == 0xffff) {
+                    if (sz < 0 || get2ByteLittleEndian(endbuf, i + 10) == 0xffff) {
                         throw new ZipFormatException("detected a zip64 archive");
                     }
                     zipRandomFile.seek(start + sz);
-                    zipRandomFile.readFully(zipDir, 2, zipDir.length - 2);
+                    zipRandomFile.readFully(zipDir, 0, zipDir.length);
                     return;
                 } else {
                     endbufend = endbufpos + 21;
@@ -568,14 +566,13 @@
         }
 
         private void buildIndex() throws IOException {
-            int entryCount = get2ByteLittleEndian(zipDir, 0);
+            int len = zipDir.length;
 
             // Add each of the files
-            if (entryCount > 0) {
+            if (len > 0) {
                 directories = new LinkedHashMap<RelativeDirectory, DirectoryEntry>();
                 ArrayList<Entry> entryList = new ArrayList<Entry>();
-                int pos = 2;
-                for (int i = 0; i < entryCount; i++) {
+                for (int pos = 0; pos < len; ) {
                     pos = readEntry(pos, entryList, directories);
                 }