From 80725d0e71f4be032e914dc3f34ec8f01489b629 Mon Sep 17 00:00:00 2001
From: Alex Alabuzhev <alabuzhev@gmail.com>
Date: Wed, 27 Nov 2024 17:22:12 +0000
Subject: [PATCH] gh-886: ArcLite crash during an archive update

---
 plugins/arclite/archive.hpp |  2 +-
 plugins/arclite/attr.cpp    | 10 ++++++++--
 plugins/arclite/changelog   |  5 +++++
 plugins/arclite/plugin.cpp  |  4 ++--
 plugins/arclite/update.cpp  |  2 +-
 plugins/arclite/version.hpp |  2 +-
 6 files changed, 18 insertions(+), 7 deletions(-)

diff --git a/plugins/arclite/archive.hpp b/plugins/arclite/archive.hpp
index e5f5f528cd..06e399bff8 100644
--- a/plugins/arclite/archive.hpp
+++ b/plugins/arclite/archive.hpp
@@ -315,7 +315,7 @@ class Archive: public std::enable_shared_from_this<Archive> {
   int m_open_password;
   bool m_update_props_defined;
   bool m_has_crc;
-  void load_update_props();
+  void load_update_props(const ArcType& arc_type);
 public:
   void create(const std::wstring& src_dir, const std::vector<std::wstring>& file_names, const UpdateOptions& options, std::shared_ptr<ErrorLog> error_log);
   void update(const std::wstring& src_dir, const std::vector<std::wstring>& file_names, const std::wstring& dst_dir, const UpdateOptions& options, std::shared_ptr<ErrorLog> error_log);
diff --git a/plugins/arclite/attr.cpp b/plugins/arclite/attr.cpp
index 4708b69d74..066363d6f8 100644
--- a/plugins/arclite/attr.cpp
+++ b/plugins/arclite/attr.cpp
@@ -447,7 +447,7 @@ void Archive::load_arc_attr() {
   }
 }
 
-void Archive::load_update_props() {
+void Archive::load_update_props(const ArcType& arc_type) {
   if (m_update_props_defined) return;
 
   m_encrypted = false;
@@ -463,7 +463,10 @@ void Archive::load_update_props() {
 
   m_level = (unsigned)-1;
   m_method.clear();
-  if ((in_arc->GetArchiveProperty(kpidMethod, prop.ref()) == S_OK && prop.is_str()) || (in_arc->GetProperty(0, kpidMethod, prop.ref()) == S_OK && prop.is_str())) {
+  if (UInt32 NumberOfItems;
+      (in_arc->GetArchiveProperty(kpidMethod, prop.ref()) == S_OK && prop.is_str()) ||
+      (in_arc->GetNumberOfItems(&NumberOfItems) && NumberOfItems && in_arc->GetProperty(0, kpidMethod, prop.ref()) == S_OK && prop.is_str())
+  ) {
     std::list<std::wstring> m_list = split(prop.get_str(), L' ');
 
     static const wchar_t *known_methods[] = { c_method_lzma, c_method_lzma2, c_method_ppmd, c_method_deflate, c_method_deflate64 };
@@ -487,6 +490,9 @@ void Archive::load_update_props() {
         break;
     }
   }
+  else if (arc_type == c_zip) {
+    m_method = c_method_deflate;
+  }
 
   if (m_level == (unsigned)-1)
     m_level = 7; // maximum
diff --git a/plugins/arclite/changelog b/plugins/arclite/changelog
index 1faba2d5bb..9149e7172d 100644
--- a/plugins/arclite/changelog
+++ b/plugins/arclite/changelog
@@ -1,3 +1,8 @@
+drkns 2024-11-27 17:23:01+00:00 - build 346
+
+1. gh-886: ArcLite crash during an archive update.
+   Improve compression method detection when updating empty archives.
+
 drkns 2024-09-15 14:00:02+01:00 - build 345
 
 1. Improve compression method detection when updating archives.
diff --git a/plugins/arclite/plugin.cpp b/plugins/arclite/plugin.cpp
index 11e5fafb6a..a47e26076e 100644
--- a/plugins/arclite/plugin.cpp
+++ b/plugins/arclite/plugin.cpp
@@ -881,7 +881,7 @@ class Plugin
           FAIL_MSG(Far::get_msg(MSG_ERROR_UPDATE_UNSUPPORTED_FOR_SINGLEFILEARCHIVE));
         }
       }
-      archive->load_update_props();
+      archive->load_update_props(options.arc_type);
       options.method = archive->m_method;
       options.solid = archive->m_solid;
       options.encrypt = archive->m_encrypted;
@@ -1127,7 +1127,7 @@ class Plugin
       archive->make_index();
 
       options.arc_type = archive->arc_chain.back().type;
-      archive->load_update_props();
+      archive->load_update_props(options.arc_type);
       if (!cmd.level_defined)
         options.level = archive->m_level;
       if (!cmd.method_defined)
diff --git a/plugins/arclite/update.cpp b/plugins/arclite/update.cpp
index 22c360274b..26e3d5dc90 100644
--- a/plugins/arclite/update.cpp
+++ b/plugins/arclite/update.cpp
@@ -1206,7 +1206,7 @@ void Archive::create_dir(const std::wstring& dir_name, const std::wstring& dst_d
 
   UpdateOptions options;
   options.arc_type = arc_chain.back().type;
-  load_update_props();
+  load_update_props(options.arc_type);
   options.level = m_level;
   options.method = m_method;
   options.solid = m_solid;
diff --git a/plugins/arclite/version.hpp b/plugins/arclite/version.hpp
index 97424e19ff..65c26ed108 100644
--- a/plugins/arclite/version.hpp
+++ b/plugins/arclite/version.hpp
@@ -1,6 +1,6 @@
 #include <farversion.hpp>
 
-#define PLUGIN_BUILD 345
+#define PLUGIN_BUILD 346
 #define PLUGIN_DESC L"Archive support for Far Manager (based on 7-Zip project)"
 #define PLUGIN_NAME L"ArcLite"
 #define PLUGIN_FILENAME L"arclite.dll"