# HG changeset patch
# User rubidium <rubidium@openttd.org>
# Date 1315590381 0
# Node ID 3fae8f4b982066734c952554e47d902c5617e30c
# Parent  791e9ba0a44ab48003175b343933757cf5bb4719
(svn r22912) -Fix [FS#4753]: another attempt at fixing a related crash (can't reproduce it though)

diff --git a/src/ai/ai_scanner.cpp b/src/ai/ai_scanner.cpp
--- a/src/ai/ai_scanner.cpp
+++ b/src/ai/ai_scanner.cpp
@@ -424,8 +424,8 @@
 
 	AIFileChecksumCreator checksum;
 	const char *tar_filename = info->GetTarFile();
-	TarList::iterator iter = _tar_list.find(tar_filename);
-	if (iter != _tar_list.end()) {
+	TarList::iterator iter;
+	if (tar_filename != NULL && (iter = _tar_list.find(tar_filename)) != _tar_list.end()) {
 		/* The main script is in a tar file, so find all files that
 		 * are in the same tar and add them to the MD5 checksumming. */
 		TarFileList::iterator tar;