From: Lasse Collin <lasse.collin@tukaani.org>
Date: Thu, 14 Jan 2021 18:57:11 +0000 (+0200)
Subject: liblzma: Fix missing normalization in rc_encode_dummy().
X-Git-Tag: v5.3.2alpha~23
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=421b0aa352da244075db10205cf33712f91b9835;p=thirdparty%2Fxz.git

liblzma: Fix missing normalization in rc_encode_dummy().

Without this fix it could attempt to create too much output.
---

diff --git a/src/liblzma/rangecoder/range_encoder.h b/src/liblzma/rangecoder/range_encoder.h
index 1bcfd7a5..5e2afafe 100644
--- a/src/liblzma/rangecoder/range_encoder.h
+++ b/src/liblzma/rangecoder/range_encoder.h
@@ -274,7 +274,7 @@ rc_encode_dummy(const lzma_range_encoder *rc, size_t out_size)
 
 	size_t pos = rc->pos;
 
-	while (pos < rc->count) {
+	while (true) {
 		// Normalize
 		if (range < RC_TOP_VALUE) {
 			if (rc_shift_low_dummy(&low, &cache_size, &cache,
@@ -284,6 +284,11 @@ rc_encode_dummy(const lzma_range_encoder *rc, size_t out_size)
 			range <<= RC_SHIFT_BITS;
 		}
 
+		// This check is here because the normalization above must
+		// be done before flushing the last bytes.
+		if (pos == rc->count)
+			break;
+
 		// Encode a bit
 		switch (rc->symbols[pos]) {
 		case RC_BIT_0: {