1 files changed, 85 insertions, 0 deletions
diff --git a/zlib/uncompr.c b/zlib/uncompr.c
new file mode 100644
index 00000000..5e256663
--- /dev/null
+++ b/zlib/uncompr.c
@@ -0,0 +1,85 @@
+/* uncompr.c -- decompress a memory buffer
+ * Copyright (C) 1995-2003, 2010, 2014, 2016 Jean-loup Gailly, Mark Adler
+ * For conditions of distribution and use, see copyright notice in zlib.h
+ */
+
+/* @(#) $Id$ */
+
+#define ZLIB_INTERNAL
+#include "zlib.h"
+
+/* ===========================================================================
+     Decompresses the source buffer into the destination buffer.  *sourceLen is
+   the byte length of the source buffer. Upon entry, *destLen is the total size
+   of the destination buffer, which must be large enough to hold the entire
+   uncompressed data. (The size of the uncompressed data must have been saved
+   previously by the compressor and transmitted to the decompressor by some
+   mechanism outside the scope of this compression library.) Upon exit,
+   *destLen is the size of the decompressed data and *sourceLen is the number
+   of source bytes consumed. Upon return, source + *sourceLen points to the
+   first unused input byte.
+
+     uncompress returns Z_OK if success, Z_MEM_ERROR if there was not enough
+   memory, Z_BUF_ERROR if there was not enough room in the output buffer, or
+   Z_DATA_ERROR if the input data was corrupted, including if the input data is
+   an incomplete zlib stream.
+*/
+int ZEXPORT uncompress2(Bytef *dest, uLongf *destLen, const Bytef *source,
+                        uLong *sourceLen) {
+    z_stream stream;
+    int err;
+    const uInt max = (uInt)-1;
+    uLong len, left;
+    Byte buf[1];    /* for detection of incomplete stream when *destLen == 0 */
+
+    len = *sourceLen;
+    if (*destLen) {
+        left = *destLen;
+        *destLen = 0;
+    }
+    else {
+        left = 1;
+        dest = buf;
+    }
+
+    stream.next_in = (z_const Bytef *)source;
+    stream.avail_in = 0;
+    stream.zalloc = (alloc_func)0;
+    stream.zfree = (free_func)0;
+    stream.opaque = (voidpf)0;
+
+    err = inflateInit(&stream);
+    if (err != Z_OK) return err;
+
+    stream.next_out = dest;
+    stream.avail_out = 0;
+
+    do {
+        if (stream.avail_out == 0) {
+            stream.avail_out = left > (uLong)max ? max : (uInt)left;
+            left -= stream.avail_out;
+        }
+        if (stream.avail_in == 0) {
+            stream.avail_in = len > (uLong)max ? max : (uInt)len;
+            len -= stream.avail_in;
+        }
+        err = inflate(&stream, Z_NO_FLUSH);
+    } while (err == Z_OK);
+
+    *sourceLen -= len + stream.avail_in;
+    if (dest != buf)
+        *destLen = stream.total_out;
+    else if (stream.total_out && err == Z_BUF_ERROR)
+        left = 1;
+
+    inflateEnd(&stream);
+    return err == Z_STREAM_END ? Z_OK :
+           err == Z_NEED_DICT ? Z_DATA_ERROR  :
+           err == Z_BUF_ERROR && left + stream.avail_out ? Z_DATA_ERROR :
+           err;
+}
+
+int ZEXPORT uncompress(Bytef *dest, uLongf *destLen, const Bytef *source,
+                       uLong sourceLen) {
+    return uncompress2(dest, destLen, source, &sourceLen);
+}