add message to ZStream on deflate error

lib/zlib/deflate.js

@@ -4,6 +4,7 @@ var utils   = require('./utils');
 var trees   = require('./trees');
 var adler32 = require('./adler32');
 var crc32   = require('./crc32');
+var msg   = require('./messages');
 
 /* Public constants ==========================================================*/
 /* ===========================================================================*/
@@ -102,6 +103,10 @@ var BS_FINISH_DONE    = 4; /* finish done, accept no more input or output */
 
 var OS_CODE = 0x03; // Unix :) . Don't detect, use this default.
 
+function err(strm, error) {
+  strm.msg = msg[error];
+  return error;
+}
 
 function rank(f) {
   return ((f) << 1) - ((f) > 4 ? 9 : 0);
@@ -1261,7 +1266,7 @@ function deflateResetKeep(strm) {
   var s;
 
   if (!strm || !strm.state) {
-    return Z_STREAM_ERROR;
+    return err(strm, Z_STREAM_ERROR);
   }
 
   strm.total_in = strm.total_out = 0;
@@ -1295,7 +1300,7 @@ function deflateReset(strm) {
 
 function deflateInit2(strm, level, method, windowBits, memLevel, strategy) {
   if (!strm) { // === Z_NULL
-    return Z_STREAM_ERROR;
+    return err(strm, Z_STREAM_ERROR);
   }
   var wrap = 1;
 
@@ -1317,7 +1322,7 @@ function deflateInit2(strm, level, method, windowBits, memLevel, strategy) {
   if (memLevel < 1 || memLevel > MAX_MEM_LEVEL || method !== Z_DEFLATED ||
     windowBits < 8 || windowBits > 15 || level < 0 || level > 9 ||
     strategy < 0 || strategy > Z_FIXED) {
-    return Z_STREAM_ERROR;
+    return err(strm, Z_STREAM_ERROR);
   }
 
 
@@ -1373,7 +1378,7 @@ function deflate(strm, flush) {
 
   if (!strm || !strm.state ||
     flush > Z_BLOCK || flush < 0) {
-    return Z_STREAM_ERROR;
+    return err(strm, Z_STREAM_ERROR);
   }
 
   s = strm.state;
@@ -1381,7 +1386,7 @@ function deflate(strm, flush) {
   if (!strm.next_out ||
       (!strm.next_in && strm.avail_in !== 0) ||
       (s.status === FINISH_STATE && flush !== Z_FINISH)) {
-    return (strm.avail_out === 0) ? Z_BUF_ERROR : Z_STREAM_ERROR;
+    return err(strm, (strm.avail_out === 0) ? Z_BUF_ERROR : Z_STREAM_ERROR);
   }
 
   s.strm = strm; /* just in case */
@@ -1462,12 +1467,12 @@ function deflate(strm, flush) {
      */
   } else if (strm.avail_in === 0 && rank(flush) <= rank(old_flush) &&
     flush !== Z_FINISH) {
-    return Z_BUF_ERROR;
+    return err(strm, Z_BUF_ERROR);
   }
 
   /* User must not provide more input after the first FINISH: */
   if (s.status === FINISH_STATE && strm.avail_in !== 0) {
-    return Z_BUF_ERROR;
+    return err(strm, Z_BUF_ERROR);
   }
 
   /* Start a new block or continue the current one.
@@ -1565,12 +1570,12 @@ function deflateEnd(strm) {
     status !== BUSY_STATE &&
     status !== FINISH_STATE
   ) {
-    return Z_STREAM_ERROR;
+    return err(strm, Z_STREAM_ERROR);
   }
 
   strm.state = null;
 
-  return status === BUSY_STATE ? Z_DATA_ERROR : Z_OK;
+  return status === BUSY_STATE ? err(strm, Z_DATA_ERROR) : Z_OK;
 }
 
 /* =========================================================================

lib/zlib/zstream.js

@@ -17,7 +17,7 @@ function ZStream() {
   /* total number of bytes output so far */
   this.total_out = 0;
   /* last error message, NULL if no error */
-  this.msg = ''/*Z_NULL*/; // for inflate only
+  this.msg = ''/*Z_NULL*/;
   /* not visible by applications */
   this.state = null;
   /* best guess about the data type: binary or text */