Fix unztell64() in minizip to work past 4GB. (Daniël Hörchner)

[zlib.git] / contrib / minizip / unzip.c

diff --git a/contrib/minizip/unzip.c b/contrib/minizip/unzip.c
index bcfb9416ec356d1016f890b085677e412ba6e9bf..b16a75e834de8674bbb5e5d750b33b95a6fc76f0 100644 (file)
--- a/contrib/minizip/unzip.c
+++ b/contrib/minizip/unzip.c
@@ -1857,6 +1857,9 @@ extern int ZEXPORT unzReadCurrentFile  (unzFile file, voidp buf, unsigned len)
               err = Z_DATA_ERROR;
 
             uTotalOutAfter = pfile_in_zip_read_info->stream.total_out;
+            /* Detect overflow, because z_stream.total_out is uLong (32 bits) */
+            if (uTotalOutAfter<uTotalOutBefore)
+                uTotalOutAfter += 1LL << 32; /* Add maximum value of uLong + 1 */
             uOutThis = uTotalOutAfter-uTotalOutBefore;
 
             pfile_in_zip_read_info->total_out_64 = pfile_in_zip_read_info->total_out_64 + uOutThis;