--- a/jdk/src/jdk.zipfs/share/classes/jdk/nio/zipfs/ZipConstants.java	Wed Mar 25 15:36:43 2015 -0700
+++ b/jdk/src/jdk.zipfs/share/classes/jdk/nio/zipfs/ZipConstants.java	Tue Mar 10 14:23:03 2015 -0700
@@ -184,10 +184,19 @@
         return (LG(b, n)) | (LG(b, n + 4) << 32);
     }
 
-    static final long GETSIG(byte[] b) {
-        return LG(b, 0);
+    static long getSig(byte[] b, int n) { return LG(b, n); }
+
+    private static boolean pkSigAt(byte[] b, int n, int b1, int b2) {
+        return b[n] == 'P' & b[n + 1] == 'K' & b[n + 2] == b1 & b[n + 3] == b2;
     }
 
+    static boolean cenSigAt(byte[] b, int n) { return pkSigAt(b, n, 1, 2); }
+    static boolean locSigAt(byte[] b, int n) { return pkSigAt(b, n, 3, 4); }
+    static boolean endSigAt(byte[] b, int n) { return pkSigAt(b, n, 5, 6); }
+    static boolean extSigAt(byte[] b, int n) { return pkSigAt(b, n, 7, 8); }
+    static boolean end64SigAt(byte[] b, int n) { return pkSigAt(b, n, 6, 6); }
+    static boolean locator64SigAt(byte[] b, int n) { return pkSigAt(b, n, 6, 7); }
+
     // local file (LOC) header fields
     static final long LOCSIG(byte[] b) { return LG(b, 0); } // signature
     static final int  LOCVER(byte[] b) { return SH(b, 4); } // version needed to extract

--- a/jdk/src/jdk.zipfs/share/classes/jdk/nio/zipfs/ZipFileSystem.java	Wed Mar 25 15:36:43 2015 -0700
+++ b/jdk/src/jdk.zipfs/share/classes/jdk/nio/zipfs/ZipFileSystem.java	Tue Mar 10 14:23:03 2015 -0700
@@ -1060,7 +1060,7 @@
         int pos = 0;
         int limit = cen.length - ENDHDR;
         while (pos < limit) {
-            if (CENSIG(cen, pos) != CENSIG)
+            if (!cenSigAt(cen, pos))
                 zerror("invalid CEN header (bad signature)");
             int method = CENHOW(cen, pos);
             int nlen   = CENNAM(cen, pos);
@@ -1894,7 +1894,7 @@
             throws IOException
         {
             byte[] cen = zipfs.cen;
-            if (CENSIG(cen, pos) != CENSIG)
+            if (!cenSigAt(cen, pos))
                 zerror("invalid CEN header (bad signature)");
             versionMade = CENVEM(cen, pos);
             version     = CENVER(cen, pos);
@@ -2057,9 +2057,9 @@
             assert (buf.length >= LOCHDR);
             if (zipfs.readFullyAt(buf, 0, LOCHDR , pos) != LOCHDR)
                 throw new ZipException("loc: reading failed");
-            if (LOCSIG(buf) != LOCSIG)
+            if (!locSigAt(buf, 0))
                 throw new ZipException("loc: wrong sig ->"
-                                       + Long.toString(LOCSIG(buf), 16));
+                                       + Long.toString(getSig(buf, 0), 16));
             //startPos = pos;
             version  = LOCVER(buf);
             flag     = LOCFLG(buf);
@@ -2289,9 +2289,9 @@
                     if (zipfs.readFullyAt(buf, 0, buf.length , locoff)
                         != buf.length)
                         throw new ZipException("loc: reading failed");
-                    if (LOCSIG(buf) != LOCSIG)
+                    if (!locSigAt(buf, 0))
                         throw new ZipException("loc: wrong sig ->"
-                                           + Long.toString(LOCSIG(buf), 16));
+                                           + Long.toString(getSig(buf, 0), 16));
 
                     int locElen = LOCEXT(buf);
                     if (locElen < 9)    // EXTT is at lease 9 bytes