Make uncompressed zip test independent of zlib.

SVN-Revision: 1080

diff --git a/libarchive/test/test_write_format_zip_no_compression.c b/libarchive/test/test_write_format_zip_no_compression.c
index c5facf49f3a0e9941c5d8e7d75884569331e5ebb..fd51030bbbe6e74605de19531b04d9f1cc7cc674 100644 (file)
--- a/libarchive/test/test_write_format_zip_no_compression.c
+++ b/libarchive/test/test_write_format_zip_no_compression.c
@@ -30,20 +30,33 @@
 #include "test.h"
 __FBSDID("$FreeBSD$");
 
-/* #include <zlib.h> */
 static unsigned long
-crc32(unsigned long c, void *p, size_t s)
+bitcrc32(unsigned long c, void *_p, size_t s)
 {
-       /* TODO: drop in a compact (but slow) bitwise CRC here to
-        * break the dependency on zlib.h; libarchive proper should be
-        * able to generate uncompressed zip archives correctly
-        * (including proper CRC even without zlib. */
-       (void)c;
-       (void)p;
-       (void)s;
-       return (0);
-}
+       /* This is a drop-in replacement for crc32() from zlib.
+        * Libarchive should be able to correctly generate
+        * uncompressed zip archives (including correct CRCs) even
+        * when zlib is unavailable, and this function helps us verify
+        * that.  Yes, this is very, very slow and unsuitable for
+        * production use, but it's correct, compact, and works well
+        * enough for this particular usage.  Libarchive internally
+        * uses a much more efficient implementation.  */
+       const unsigned char *p = _p;
+       int bitctr;
+
+       if (p == NULL)
+               return (0);
 
+       for (; s > 0; --s) {
+               c ^= *p++;
+               for (bitctr = 8; bitctr > 0; --bitctr) {
+                       if (c & 1) c = (c >> 1);
+                       else       c = (c >> 1) ^ 0xedb88320;
+                       c ^= 0x80000000;
+               }
+       }
+       return (c);
+}
 
 /* Quick and dirty: Read 2-byte and 4-byte integers from Zip file. */
 static int i2(const char *p) { return ((p[0] & 0xff) | ((p[1] & 0xff) << 8)); }
@@ -158,8 +171,8 @@ DEFINE_TEST(test_write_format_zip_no_compression)
        assertEqualInt(i2(p + 10), 0); /* Compression method */
        assertEqualInt(i2(p + 12), (tm->tm_hour * 2048) + (tm->tm_min * 32) + (tm->tm_sec / 2)); /* File time */
        assertEqualInt(i2(p + 14), ((tm->tm_year - 80) * 512) + ((tm->tm_mon + 1) * 32) + tm->tm_mday); /* File date */
-       crc = crc32(0, (void *)file_data1, sizeof(file_data1));
-       crc = crc32(crc, (void *)file_data2, sizeof(file_data2));
+       crc = bitcrc32(0, (void *)file_data1, sizeof(file_data1));
+       crc = bitcrc32(crc, (void *)file_data2, sizeof(file_data2));
        assertEqualInt(i4(p + 16), crc); /* CRC-32 */
        assertEqualInt(i4(p + 20), sizeof(file_data1) + sizeof(file_data2)); /* Compressed size */
        assertEqualInt(i4(p + 24), sizeof(file_data1) + sizeof(file_data2)); /* Uncompressed size */