X-Git-Url: https://git.mxchange.org/?a=blobdiff_plain;f=zlib%2Fgzio.c;h=f7c336a55a0911bdd45fcd9caa10c8570b3c5d6c;hb=39521df546830fec63ee1847d9e1c13e4cc3150c;hp=e29198ac7afaf76999c0c6e00908005cb12a4d68;hpb=6dd8a1525c2e3981ceaec30982b584d67a21d897;p=simgear.git

diff --git a/zlib/gzio.c b/zlib/gzio.c
index e29198ac..f7c336a5 100644
--- a/zlib/gzio.c
+++ b/zlib/gzio.c
@@ -414,10 +414,14 @@ int ZEXPORT gzread (file, buf, len)
 	    s->crc = crc32(s->crc, start, (uInt)(s->stream.next_out - start));
 	    start = s->stream.next_out;
 
-	    if (getLong(s) != s->crc || getLong(s) != s->stream.total_out) {
+	    if (getLong(s) != s->crc) {
 		s->z_err = Z_DATA_ERROR;
 	    } else {
-		/* Check for concatenated .gz files: */
+	        (void)getLong(s);
+                /* The uncompressed length returned by above getlong() may
+                 * be different from s->stream.total_out) in case of
+		 * concatenated .gz files. Check for such files:
+		 */
 		check_header(s);
 		if (s->z_err == Z_OK) {
 		    uLong total_in = s->stream.total_in;
@@ -670,7 +674,7 @@ z_off_t ZEXPORT gzseek (file, offset, whence)
 	return -1L;
 #else
 	if (whence == SEEK_SET) {
-	    offset -= s->stream.total_out;
+	    offset -= s->stream.total_in;
 	}
 	if (offset < 0) return -1L;
 
@@ -745,6 +749,7 @@ int ZEXPORT gzrewind (file)
     s->z_eof = 0;
     s->stream.avail_in = 0;
     s->stream.next_in = s->inbuf;
+    s->crc = crc32(0L, Z_NULL, 0);
 	
     if (s->startpos == 0) { /* not a compressed file */
 	rewind(s->file);
@@ -793,7 +798,8 @@ local void putLong (file, x)
 }
 
 /* ===========================================================================
-   Reads a long in LSB order from the given gz_stream. Sets 
+   Reads a long in LSB order from the given gz_stream. Sets z_err in case
+   of error.
 */
 local uLong getLong (s)
     gz_stream *s;