X-Git-Url: https://wimlib.net/git/?p=wimlib;a=blobdiff_plain;f=src%2Flzx-decompress.c;h=96332dd8f40cf6066ed43d19c482d38c7c6e5408;hp=a24b0832e14be6b955499a621b0da710347cb833;hb=926ff6c5ed956b96fcb521b2c20afcf9ac890b14;hpb=6b8d739e7c68237499366546eb41bc4cb3fff9d4

diff --git a/src/lzx-decompress.c b/src/lzx-decompress.c
index a24b0832..96332dd8 100644
--- a/src/lzx-decompress.c
+++ b/src/lzx-decompress.c
@@ -656,8 +656,6 @@ lzx_decode_match(unsigned main_element, int block_type,
 	/* Verify that the match is in the bounds of the part of the window
 	 * currently in use, then copy the source of the match to the current
 	 * position. */
-	match_dest = window + window_pos;
-	match_src = match_dest - match_offset;
 
 	if (match_len > bytes_remaining) {
 		DEBUG("lzx_decode_match(): Match of length %u bytes overflows "
@@ -665,13 +663,16 @@ lzx_decode_match(unsigned main_element, int block_type,
 		return -1;
 	}
 
-	if (match_src < window) {
+	if (match_offset > window_pos) {
 		DEBUG("lzx_decode_match(): Match of length %u bytes references "
 		      "data before window (match_offset = %u, window_pos = %u)",
 		      match_len, match_offset, window_pos);
 		return -1;
 	}
 
+	match_dest = window + window_pos;
+	match_src = match_dest - match_offset;
+
 #if 0
 	printf("Match: src %u, dst %u, len %u\n", match_src - window,
 						match_dest - window,