diff --git a/deps/libz/inflate.c b/deps/libz/inflate.c
index 16c741df26..5403a7bfc0 100644
--- a/deps/libz/inflate.c
+++ b/deps/libz/inflate.c
@@ -276,7 +276,7 @@ int inflatePrime(z_streamp strm, int bits, int value)
       return Z_STREAM_ERROR;
 
    value         &= (1L << bits) - 1;
-   state->hold   += value << state->bits;
+   state->hold   += (unsigned)value << state->bits;
    state->bits   += bits;
 
    return Z_OK;
@@ -603,6 +603,8 @@ int inflate(z_streamp strm, int flush)
             NEEDBITS(16);
 #ifdef GUNZIP
             if ((state->wrap & 2) && hold == 0x8b1f) {  /* gzip header */
+               if (state->wbits == 0)
+                  state->wbits  = 15;
                state->check = crc32(0L, Z_NULL, 0);
                CRC2(state->check, hold);
                INITBITS();
@@ -629,8 +631,8 @@ int inflate(z_streamp strm, int flush)
                   DROPBITS(4);
                   len = BITS(4) + 8;
                   if (state->wbits == 0)
-                  state->wbits = len;
-                  else if (len > state->wbits) {
+                     state->wbits = len;
+                  if (len > 15 || len > state->wbits) {
                   strm->msg = (char *)"invalid window size";
                   state->mode = BAD;
                   break;
@@ -1484,10 +1486,10 @@ long inflateMark(z_streamp strm)
 
    if (  strm        == Z_NULL || 
          strm->state == Z_NULL)
-	   return -1L << 16;
+      return -(1L << 16);
 
    state = (struct inflate_state FAR *)strm->state;
-   return ((long)(state->back) << 16) +
+   return (long)(((unsigned long)((long)state->back)) << 16) +
        (state->mode == COPY  ? state->length :
        (state->mode == MATCH ? state->was - state->length : 0));
 }
diff --git a/deps/libz/trees.c b/deps/libz/trees.c
index 6cae8f3dde..0d609ae15f 100644
--- a/deps/libz/trees.c
+++ b/deps/libz/trees.c
@@ -103,8 +103,6 @@ static int  detect_data_type (deflate_state *s);
 static unsigned bi_reverse (unsigned value, int length);
 static void bi_windup      (deflate_state *s);
 static void bi_flush       (deflate_state *s);
-static void copy_block     (deflate_state *s, charf *buf, unsigned len,
-         int header);
 
 #  define send_code(s, c, tree) send_bits(s, tree[c].Code, tree[c].Len)
 /* Send a code of the given tree. c and tree must not have side effects */
@@ -595,7 +593,11 @@ static void send_all_trees(deflate_state *s, int lcodes, int dcodes, int blcodes
 void ZLIB_INTERNAL _tr_stored_block(deflate_state *s, charf *buf, ulg stored_len, int last)
 {
    send_bits(s, (STORED_BLOCK<<1)+last, 3);    /* send block type */
-   copy_block(s, buf, (unsigned)stored_len, 1); /* with header */
+   bi_windup(s);        /* align on byte boundary */
+   put_short(s, (ush)stored_len);
+   put_short(s, (ush)~stored_len);
+   memcpy(s->pending_buf + s->pending, buf, stored_len);
+   s->pending += stored_len;
 }
 
 /* ===========================================================================
@@ -874,20 +876,3 @@ void ZLIB_INTERNAL _tr_flush_block(deflate_state *s, charf *buf, ulg stored_len,
       s->bi_buf = 0;
       s->bi_valid = 0;
    }
-
-   /* ===========================================================================
-    * Copy a stored block, storing first the length and its
-    * one's complement if requested.
-    */
-   static void copy_block(deflate_state *s, charf *buf, unsigned len, int header)
-   {
-      bi_windup(s);        /* align on byte boundary */
-
-      if (header) {
-         put_short(s, (ush)len);
-         put_short(s, (ush)~len);
-      }
-      while (len--) {
-         put_byte(s, *buf++);
-      }
-   }