From: Eric Biggers <ebiggers3@gmail.com>
Date: Wed, 19 Dec 2012 04:24:52 +0000 (-0600)
Subject: Fix xpress_compress() minimum size
X-Git-Tag: v1.2.1~14
X-Git-Url: https://wimlib.net/git/?p=wimlib;a=commitdiff_plain;h=c9812a5d413382b81552979b10e5c478b3721316

Fix xpress_compress() minimum size
---

diff --git a/src/xpress-compress.c b/src/xpress-compress.c
index 77df5279..2b3a6a6e 100644
--- a/src/xpress-compress.c
+++ b/src/xpress-compress.c
@@ -169,8 +169,14 @@ int xpress_compress(const void *__uncompressed_data, unsigned uncompressed_len,
 
 	/* XPRESS requires 256 bytes of overhead for the Huffman tables, so it's
 	 * impossible cannot compress 256 bytes or less of data to less than the
-	 * input size. */
-	if (uncompressed_len <= XPRESS_NUM_SYMBOLS / 2)
+	 * input size.
+	 *
+	 * +1 to take into account that the buffer for compressed data is 1 byte
+	 * smaller than the buffer for uncompressed data.
+	 *
+	 * +4 to take into account that init_output_bitstream() requires at
+	 * least 4 bytes of data. */
+	if (uncompressed_len < XPRESS_NUM_SYMBOLS / 2 + 1 + 4)
 		return 1;
 
 	ZERO_ARRAY(freq_tab);