1 files changed, 33 insertions, 23 deletions

diff --git a/inflate.c b/inflate.c
index 478f46d..38d70cc 100644
--- a/inflate.c
+++ b/inflate.c
@@ -25,10 +25,6 @@ struct internal_state {
       ERROR}    /* got an error--stay here */
     mode;               /* current inflate mode */
 
-  int  no_header;
-  uInt w_size;  /* LZ77 window size (32K by default) */
-  uInt w_bits;  /* log2(w_size)  (8..16) */
-
   /* mode dependent information */
   union {
     uInt method;        /* if FLAGS, method byte */
@@ -39,19 +35,26 @@ struct internal_state {
       uLong need;               /* stream check value */
     } check;            /* if CHECK, check values to compare */
   } sub;        /* submode */
+
+  /* mode independent information */
+  int  nowrap;          /* flag for no wrapper */
+  uInt wbits;           /* log2(window size)  (8..15, defaults to 15) */
+
 };
 
 
-int inflateInit (strm)
-z_stream *strm;
+int inflateInit(z)
+z_stream *z;
 {
-    return inflateInit2(strm, WBITS);
+    return inflateInit2(z, WBITS);
 }
 
-int inflateInit2(z, windowBits)
+
+int inflateInit2(z, w)
 z_stream *z;
-int windowBits;
+int w;
 {
+  /* initialize state */
   if (z == Z_NULL)
     return Z_STREAM_ERROR;
   if (z->zalloc == Z_NULL) z->zalloc = zcalloc;
@@ -63,19 +66,22 @@ int windowBits;
     return Z_MEM_ERROR;
   z->state->mode = METHOD;
 
-  z->state->no_header = 0;
-  if (windowBits < 0) { /* undocumented feature: no zlib header */
-    windowBits = - windowBits;
-    z->state->no_header = 1;
-    z->state->sub.method = DEFLATED;
+  /* handle undocumented nowrap option (no zlib header or check) */
+  z->state->nowrap = 0;
+  if (w < 0)
+  {
+    w = - w;
+    z->state->nowrap = 1;
     z->state->mode = START;
   }
-  if (windowBits < 8 || windowBits > 15) {
+
+  /* set window size */
+  if (w < 8 || w > 15)
+  {
     inflateEnd(z);
     return Z_STREAM_ERROR;
   }
-  z->state->w_bits = windowBits;
-  z->state->w_size = 1<<windowBits;
+  z->state->wbits = w;
   return Z_OK;
 }
 
@@ -103,7 +109,7 @@ int f;
         z->msg = "unknown compression method";
         return Z_DATA_ERROR;
       }
-      if ((z->state->sub.method >> 4) > z->state->w_bits)
+      if ((z->state->sub.method >> 4) + 8 > z->state->wbits)
       {
         z->state->mode = ERROR;
         z->msg = "invalid window size";
@@ -126,17 +132,21 @@ int f;
       }
       z->state->mode = START;
     case START:
-      if ((z->state->sub.blocks = inflate_blocks_new(z,z->state->w_size))
-          == Z_NULL)
+      if ((z->state->sub.blocks = inflate_blocks_new(z,
+         z->state->nowrap ? Z_NULL : adler32,
+         1<< z->state->wbits)) == Z_NULL)
         return Z_MEM_ERROR;
       z->state->mode = BLOCKS;
     case BLOCKS:
       if ((r = inflate_blocks(z->state->sub.blocks, z, r)) != Z_STREAM_END)
         return r;
       inflate_blocks_free(z->state->sub.blocks, z, &c, &r);
-      if (z->state->no_header) {
-        z->state->mode = DONE;
-        return Z_STREAM_END;
+      if (z->state->nowrap)
+      {
+        if (r != -1)
+          z->msg = "inflate bug--took one too many bytes";
+        z->state->mode = r == -1 ? DONE : ERROR;
+        break;
       }
       z->state->sub.check.was = c;
       if (r != -1)