zlib: wrap inflateInit2 used to accept only for gzip format

diff --git a/zlib.c b/zlib.c
index be9d7e963b88ac20cf4639de9dd4ddaaf3ff7a80..b613cbd75085384df2ec87fcf2475f7d154f55ff 100644 (file)
--- a/zlib.c
+++ b/zlib.c
@@ -32,6 +32,21 @@ void git_inflate_init(z_streamp strm)
            strm->msg ? strm->msg : "no message");
 }
 
+void git_inflate_init_gzip_only(z_streamp strm)
+{
+       /*
+        * Use default 15 bits, +16 is to accept only gzip and to
+        * yield Z_DATA_ERROR when fed zlib format.
+        */
+       const int windowBits = 15 + 16;
+       int status = inflateInit2(strm, windowBits);
+
+       if (status == Z_OK)
+               return;
+       die("inflateInit2: %s (%s)", zerr_to_string(status),
+           strm->msg ? strm->msg : "no message");
+}
+
 void git_inflate_end(z_streamp strm)
 {
        int status = inflateEnd(strm);