More Zip64 fixes.

Author: jfreilly

src/Zip/ZipEntry.cs

@@ -646,7 +646,8 @@ public bool LocalHeaderRequiresZip64
 
 					// TODO: A better estimation of the true limit based on compression overhead should be used
 					// to determine when an entry should use Zip64.
-					result = ((this.size >= uint.MaxValue) || (trueCompressedSize >= uint.MaxValue)) &&
+					result =
+						((this.size >= uint.MaxValue) || (trueCompressedSize >= uint.MaxValue) || (this.offset >= uint.MaxValue)) &&
 						((versionToExtract == 0) || (versionToExtract >= ZipConstants.VersionZip64));
 				}
 
@@ -660,7 +661,7 @@ public bool LocalHeaderRequiresZip64
 		public bool CentralHeaderRequiresZip64
 		{
 			get {
-				return LocalHeaderRequiresZip64 || (offset >= 0xffffffff);
+				return LocalHeaderRequiresZip64;
 			}
 		}
 
@@ -869,6 +870,10 @@ internal void ProcessExtraData(bool localHeader)
 				if ( localHeader || (compressedSize == uint.MaxValue) ) {
 					compressedSize = (ulong)extraData.ReadLong();
 				}
+
+				if ( !localHeader && (offset == -1) ) {
+					offset = extraData.ReadLong();
+				}
 			}
 			else {
 				if ( 

src/Zip/ZipFile.cs

@@ -2910,6 +2910,9 @@ void ReadEntries()
 				entry.CompressedSize = csize & 0xffffffffL;
 				entry.Flags = bitFlags;
 				entry.DosTime = (uint)dostime;
+				entry.ZipFileIndex = (long)i;
+				entry.Offset = offset;
+				entry.ExternalFileAttributes = (int)externalAttributes;
 
 				if ((bitFlags & 8) == 0) {
 					entry.CryptoCheckValue = (byte)(crc >> 24);
@@ -2931,10 +2934,6 @@ void ReadEntries()
 					entry.Comment = ZipConstants.ConvertToStringExt(bitFlags, buffer, commentLen);
 				}
 
-				entry.ZipFileIndex           = (long)i;
-				entry.Offset                 = offset;
-				entry.ExternalFileAttributes = (int)externalAttributes;
-				
 				entries_[i] = entry;
 			}
 		}