fix Bug #43793: zlib filter is unable to auto-detect gzip/zlib file headers

Author: Greg Beaver

ext/zlib/tests/zlib_filter_inflate2.phpt

@@ -0,0 +1,41 @@
+--TEST--
+zlib.inflate of gzip-encoded stream
+--SKIPIF--
+<?php if (!extension_loaded("zlib")) print "skip"; ?>
+--FILE--
+<?php /* $Id$ */
+
+$a = gzopen(dirname(__FILE__) . '/test.txt.gz', 'w');
+fwrite($a, "This is quite the thing ain't it\n");
+fclose($a);
+
+$fp = fopen(dirname(__FILE__) . '/test.txt.gz', 'r');
+stream_filter_append($fp, 'zlib.inflate', STREAM_FILTER_READ);
+echo fread($fp, 2000);
+fclose($fp);
+echo "1\n";
+$fp = fopen(dirname(__FILE__) . '/test.txt.gz', 'r');
+// zlib format
+$fp = fopen(dirname(__FILE__) . '/test.txt.gz', 'r');
+stream_filter_append($fp, 'zlib.inflate', STREAM_FILTER_READ, array('window' => 15+16));
+echo "2\n";
+echo fread($fp, 2000);
+fclose($fp);
+// auto-detect
+$fp = fopen(dirname(__FILE__) . '/test.txt.gz', 'r');
+stream_filter_append($fp, 'zlib.inflate', STREAM_FILTER_READ, array('window' => 15+32));
+echo "3\n";
+echo fread($fp, 2000);
+fclose($fp);
+
+?>
+--CLEAN--
+<?php
+@unlink(dirname(__FILE__) . '/test.txt.gz');
+?>
+--EXPECT--
+1
+2
+This is quite the thing ain't it
+3
+This is quite the thing ain't it

ext/zlib/zlib_filter.c

@@ -323,7 +323,7 @@ static php_stream_filter *php_zlib_filter_create(const char *filtername, zval *f
 				/* log-2 base of history window (9 - 15) */
 				SEPARATE_ZVAL(tmpzval);
 				convert_to_long_ex(tmpzval);
-				if (Z_LVAL_PP(tmpzval) < -MAX_WBITS || Z_LVAL_PP(tmpzval) > MAX_WBITS) {
+				if (Z_LVAL_PP(tmpzval) < -MAX_WBITS || Z_LVAL_PP(tmpzval) > MAX_WBITS + 32) {
 					php_error_docref(NULL TSRMLS_CC, E_WARNING, "Invalid parameter give for window size. (%ld)", Z_LVAL_PP(tmpzval));
 				} else {
 					windowBits = Z_LVAL_PP(tmpzval);