Change gzip header extra to native array for convenience

lib/utils/common.js

@@ -38,9 +38,7 @@ exports.shrinkBuf = function (buf, size) {
 
 var fnTyped = {
   arraySet: function (dest, src, src_offs, len, dest_offs) {
-    // Suppose, that with typed array support destination is
-    // always typed - don't check it
-    if (src.subarray) {
+    if (src.subarray && dest.subarray) {
       dest.set(src.subarray(src_offs, src_offs+len), dest_offs);
       return;
     }

lib/zlib/gzheader.js

@@ -13,21 +13,24 @@ function GZheader() {
   /* pointer to extra field or Z_NULL if none */
   this.extra      = null;
   /* extra field length (valid if extra != Z_NULL) */
-  this.extra_len  = 0;
+  this.extra_len  = 0; // Actually, we don't need it in JS,
+                       // but leave for few code modifications
 
-  /* setup limits is not necessary because in js we should not preallocate memory */
-  /* for inflate use constant limit in 65536 bytes */
+  //
+  // Setup limits is not necessary because in js we should not preallocate memory 
+  // for inflate use constant limit in 65536 bytes
+  //
 
   /* space at extra (only when reading header) */
-  /*this.extra_max  = 0;*/
+  // this.extra_max  = 0;
   /* pointer to zero-terminated file name or Z_NULL */
   this.name       = '';
   /* space at name (only when reading header) */
-  /*this.name_max   = 0;*/
+  // this.name_max   = 0;
   /* pointer to zero-terminated comment or Z_NULL */
   this.comment    = '';
   /* space at comment (only when reading header) */
-  /*this.comm_max   = 0;*/
+  // this.comm_max   = 0;
   /* true if there was or will be a header crc */
   this.hcrc       = 0;
   /* true when done reading gzip header (not used when writing a gzip file) */

lib/zlib/inflate.js

@@ -603,14 +603,16 @@ function inflate(strm, flush) {
           if (state.head) {
             len = state.head.extra_len - state.length;
             if (!state.head.extra) {
-              state.head.extra = new utils.Buf8(state.head.extra_len);
+              // Use untyped array for more conveniend processing later
+              state.head.extra = new Array(state.head.extra_len);
             }
             utils.arraySet(
               state.head.extra,
               input,
               next,
-              /* use constant limit because of extra field limitation in 65536 bytes */
-              len + copy > 65536 - len ? 65536 : copy,
+              // extra field is limited to 65536 bytes
+              // - no need for additional size check
+              copy,
               /*len + copy > state.head.extra_max - len ? state.head.extra_max : copy,*/
               len
             );