Don't deactivate excess active plugins on load

Otherwise because only the first 255 normal plugins are loaded, if you
move plugins around in the load order, you can change which active
plugins are within the first 255, and so end up deactivating plugins
the game would have loaded.

ffi/src/handle.rs

@@ -227,10 +227,6 @@ pub unsafe extern "C" fn lo_is_ambiguous(handle: lo_game_handle, result: *mut bo
 /// For the case of a plugin appearing multiple times in a load order / active plugin list,
 /// libloadorder discards all but the last instance of that plugin.
 ///
-/// For the case of more than 255 plugins being active, libloadorder deactivates as many plugins as
-/// required to bring the number of plugins active below 256, starting from the end of the load
-/// order and working towards the beginning.
-///
 /// This can be useful for when plugins are uninstalled manually or by a utility that does not also
 /// update the load order / active plugins systems correctly.
 ///

ffi/src/lib.rs

@@ -100,7 +100,11 @@
 //! there may be additional conditions that may be enforced by the game.
 //!
 //! Libloadorder is less strict when loading load orders and will adjust them at load time to be
-//! valid, similar to game behaviour.
+//! valid, similar to game behaviour. The exception to this adjustment is that the set of active
+//! plugins is not reduced in size if too many plugins are active, so that it is preserved when
+//! changing the order in which plugins are loaded. As such, while libloadorder will refuse to
+//! activate too many plugins, it will preserve a load order that already has too many plugins
+//! activated.
 
 use std::cell::RefCell;
 use std::ffi::CString;

src/load_order/asterisk_based.rs

@@ -103,8 +103,6 @@ impl WritableLoadOrder for AsteriskBasedLoadOrder {
 
         self.add_implicitly_active_plugins()?;
 
-        self.deactivate_excess_plugins();
-
         Ok(())
     }
 
@@ -653,21 +651,6 @@ mod tests {
         assert_eq!(1, load_order.active_plugin_names().len());
     }
 
-    #[test]
-    fn load_should_deactivate_excess_normal_plugins_and_light_masters_using_separate_limits() {
-        let tmp_dir = tempdir().unwrap();
-        let mut load_order = prepare(GameId::SkyrimSE, &tmp_dir.path());
-
-        let plugins = prepare_bulk_plugins(load_order.game_settings());
-
-        load_order.load().unwrap();
-        let active_plugin_names = load_order.active_plugin_names();
-
-        assert_eq!(4351, active_plugin_names.len());
-        assert_eq!(plugins[..255], active_plugin_names[..255]);
-        assert_eq!(plugins[261..4357], active_plugin_names[255..]);
-    }
-
     #[test]
     fn load_should_not_duplicate_a_plugin_that_has_a_ghosted_duplicate() {
         let tmp_dir = tempdir().unwrap();

src/load_order/mutable.rs

@@ -107,12 +107,6 @@ pub trait MutableLoadOrder: ReadableLoadOrder + ReadableLoadOrderBase + Sync {
         }
     }
 
-    fn deactivate_excess_plugins(&mut self) {
-        for index in get_excess_active_plugin_indices(self) {
-            self.plugins_mut()[index].deactivate();
-        }
-    }
-
     fn move_or_insert_plugin_with_index(
         &mut self,
         plugin_name: &str,
@@ -310,38 +304,6 @@ fn count_plugins(
         .count()
 }
 
-fn get_excess_active_plugin_indices<T: MutableLoadOrder + ?Sized>(load_order: &T) -> Vec<usize> {
-    let implicitly_active_plugins = load_order.game_settings().implicitly_active_plugins();
-    let mut normal_active_count = load_order.count_active_normal_plugins();
-    let mut light_plugin_active_count = load_order.count_active_light_plugins();
-
-    let mut plugin_indices: Vec<usize> = Vec::new();
-    for (index, plugin) in load_order.plugins().iter().enumerate().rev() {
-        if normal_active_count <= MAX_ACTIVE_NORMAL_PLUGINS
-            && light_plugin_active_count <= MAX_ACTIVE_LIGHT_PLUGINS
-        {
-            break;
-        }
-
-        let can_deactivate = plugin.is_active()
-            && !implicitly_active_plugins
-                .iter()
-                .any(|i| plugin.name_matches(i));
-
-        if can_deactivate {
-            if plugin.is_light_plugin() && light_plugin_active_count > MAX_ACTIVE_LIGHT_PLUGINS {
-                plugin_indices.push(index);
-                light_plugin_active_count -= 1;
-            } else if !plugin.is_light_plugin() && normal_active_count > MAX_ACTIVE_NORMAL_PLUGINS {
-                plugin_indices.push(index);
-                normal_active_count -= 1;
-            }
-        }
-    }
-
-    plugin_indices
-}
-
 fn validate_master_file_index(
     plugins: &[Plugin],
     plugin: &Plugin,

src/load_order/textfile_based.rs

@@ -149,8 +149,6 @@ impl WritableLoadOrder for TextfileBasedLoadOrder {
 
         self.add_implicitly_active_plugins()?;
 
-        self.deactivate_excess_plugins();
-
         Ok(())
     }
 
@@ -696,45 +694,6 @@ mod tests {
         assert_eq!(1, load_order.active_plugin_names().len());
     }
 
-    #[test]
-    fn load_should_deactivate_excess_plugins_not_including_implicitly_active_plugins() {
-        let tmp_dir = tempdir().unwrap();
-        let mut load_order = prepare(GameId::Skyrim, &tmp_dir.path());
-
-        let mut plugins: Vec<String> = Vec::new();
-        plugins.push(load_order.game_settings().master_file().to_string());
-        for i in 0..260 {
-            plugins.push(format!("Blank{}.esm", i));
-            copy_to_test_dir(
-                "Blank - Different.esm",
-                &plugins.last().unwrap(),
-                load_order.game_settings(),
-            );
-        }
-        copy_to_test_dir("Blank.esm", "Update.esm", &load_order.game_settings());
-
-        {
-            let plugins_as_ref: Vec<&str> = plugins.iter().map(AsRef::as_ref).collect();
-            write_active_plugins_file(load_order.game_settings(), &plugins_as_ref);
-            set_timestamps(
-                &load_order.game_settings().plugins_directory(),
-                &plugins_as_ref,
-            );
-        }
-
-        plugins = plugins[0..254].to_vec();
-        plugins.push("Update.esm".to_string());
-
-        load_order.load().unwrap();
-        let active_plugin_names = load_order.active_plugin_names();
-
-        assert_eq!(255, active_plugin_names.len());
-        for i in 0..255 {
-            assert_eq!(plugins[i], active_plugin_names[i]);
-        }
-        assert_eq!(plugins, active_plugin_names);
-    }
-
     #[test]
     fn load_should_not_duplicate_a_plugin_that_is_ghosted_and_in_load_order_file() {
         let tmp_dir = tempdir().unwrap();

src/load_order/timestamp_based.rs

@@ -119,8 +119,6 @@ impl WritableLoadOrder for TimestampBasedLoadOrder {
 
         self.add_implicitly_active_plugins()?;
 
-        self.deactivate_excess_plugins();
-
         Ok(())
     }
 
@@ -547,43 +545,6 @@ mod tests {
         assert_eq!(expected_filenames, load_order.active_plugin_names());
     }
 
-    #[test]
-    fn load_should_deactivate_excess_plugins() {
-        let tmp_dir = tempdir().unwrap();
-        let mut load_order = prepare(GameId::Oblivion, &tmp_dir.path());
-
-        let mut plugins: Vec<String> = Vec::new();
-        plugins.push(load_order.game_settings().master_file().to_string());
-        for i in 0..260 {
-            plugins.push(format!("Blank{}.esm", i));
-            copy_to_test_dir(
-                "Blank.esm",
-                &plugins.last().unwrap(),
-                load_order.game_settings(),
-            );
-        }
-
-        {
-            let plugins_as_ref: Vec<&str> = plugins.iter().map(AsRef::as_ref).collect();
-            write_active_plugins_file(load_order.game_settings(), &plugins_as_ref);
-            set_timestamps(
-                &load_order.game_settings().plugins_directory(),
-                &plugins_as_ref,
-            );
-        }
-
-        plugins = plugins[0..255].to_vec();
-
-        load_order.load().unwrap();
-        let active_plugin_names = load_order.active_plugin_names();
-
-        assert_eq!(255, active_plugin_names.len());
-        for i in 0..255 {
-            assert_eq!(plugins[i], active_plugin_names[i]);
-        }
-        assert_eq!(plugins, active_plugin_names);
-    }
-
     #[test]
     fn save_should_preserve_the_existing_set_of_timestamps() {
         let tmp_dir = tempdir().unwrap();