From 8e074349e47ea6832b8fdf9244e581d453733433 Mon Sep 17 00:00:00 2001
From: Lasse Collin <lasse.collin@tukaani.org>
Date: Wed, 30 Apr 2008 22:16:17 +0300
Subject: [PATCH] Fix a crash with --format=alone if other filters than LZMA
 are specified on the command line.

---
 src/lzma/args.c | 9 +++++++++
 1 file changed, 9 insertions(+)

diff --git a/src/lzma/args.c b/src/lzma/args.c
index 24fc0939..4393a6bd 100644
--- a/src/lzma/args.c
+++ b/src/lzma/args.c
@@ -462,6 +462,15 @@ set_compression_settings(void)
 	// Terminate the filter options array.
 	opt_filters[filter_count].id = LZMA_VLI_VALUE_UNKNOWN;
 
+	// If we are using the LZMA_Alone format, allow exactly one filter
+	// which has to be LZMA.
+	if (opt_header == HEADER_ALONE && (filter_count != 1
+			|| opt_filters[0].id != LZMA_FILTER_LZMA)) {
+		errmsg(V_ERROR, _("With --format=alone only the LZMA filter "
+				"is supported"));
+		my_exit(ERROR);
+	}
+
 	// Optimize the filter chain a little by removing all
 	// Copy filters.
 	for (size_t i = 0; opt_filters[i].id != LZMA_VLI_VALUE_UNKNOWN; ++i) {