feat: toggle hiding merge commits in revlog

Press Shift+M on the log tab to filter merge commits (like git log
--no-merges). Rebuilds the async log walk with a parent-count filter.

Fixes #2830

Co-authored-by: Cursor <cursoragent@cursor.com>

asyncgit/src/revlog.rs

@@ -145,6 +145,13 @@ impl AsyncLog {
 		Ok(false)
 	}
 
+	///
+	pub fn invalidate(&self) {
+		if let Ok(mut head) = self.current_head.lock() {
+			*head = None;
+		}
+	}
+
 	///
 	pub fn fetch(&self) -> Result<FetchStatus> {
 		self.background.store(false, Ordering::Relaxed);

asyncgit/src/sync/commit_filter.rs

@@ -222,3 +222,15 @@ pub fn filter_commit_by_search(
 		},
 	))
 }
+
+///
+pub fn filter_commits_exclude_merges() -> SharedCommitFilterFn {
+	Arc::new(Box::new(
+		move |repo: &Repository,
+		      commit_id: &CommitId|
+		      -> Result<bool> {
+			let commit = repo.find_commit((*commit_id).into())?;
+			Ok(commit.parent_count() <= 1)
+		},
+	))
+}

asyncgit/src/sync/mod.rs

@@ -51,7 +51,8 @@ pub use commit_details::{
 };
 pub use commit_files::get_commit_files;
 pub use commit_filter::{
-	diff_contains_file, filter_commit_by_search, LogFilterSearch,
+	diff_contains_file, filter_commit_by_search,
+	filter_commits_exclude_merges, LogFilterSearch,
 	LogFilterSearchOptions, SearchFields, SearchOptions,
 	SharedCommitFilterFn,
 };

src/components/commitlist.rs

@@ -62,6 +62,10 @@ pub struct CommitList {
 
 impl CommitList {
 	///
+	pub fn set_title(&mut self, title: impl Into<Box<str>>) {
+		self.title = title.into();
+	}
+
 	pub fn new(env: &Environment, title: &str) -> Self {
 		Self {
 			repo: env.repo.clone(),

src/keys/key_list.rs

@@ -88,6 +88,7 @@ pub struct KeysList {
 	pub log_reset_commit: GituiKeyEvent,
 	pub log_reword_commit: GituiKeyEvent,
 	pub log_find: GituiKeyEvent,
+	pub log_hide_merges: GituiKeyEvent,
 	pub find_commit_sha: GituiKeyEvent,
 	pub commit_amend: GituiKeyEvent,
 	pub toggle_signoff: GituiKeyEvent,
@@ -186,6 +187,7 @@ impl Default for KeysList {
 			log_reset_commit: GituiKeyEvent { code: KeyCode::Char('R'), modifiers: KeyModifiers::SHIFT },
 			log_reword_commit: GituiKeyEvent { code: KeyCode::Char('r'), modifiers: KeyModifiers::empty() },
 			log_find: GituiKeyEvent { code: KeyCode::Char('f'), modifiers: KeyModifiers::empty() },
+			log_hide_merges: GituiKeyEvent::new(KeyCode::Char('M'), KeyModifiers::SHIFT),
 			find_commit_sha: GituiKeyEvent::new(KeyCode::Char('j'), KeyModifiers::CONTROL),
 			commit_amend: GituiKeyEvent::new(KeyCode::Char('a'),  KeyModifiers::CONTROL),
 			toggle_signoff: GituiKeyEvent::new(KeyCode::Char('s'),  KeyModifiers::CONTROL),

src/strings.rs

@@ -300,8 +300,12 @@ pub fn confirm_msg_force_push(
         "Confirm force push to branch '{branch_ref}' ?  This may rewrite history."
     )
 }
-pub fn log_title(_key_config: &SharedKeyConfig) -> String {
-	"Commit".to_string()
+pub fn log_title(hide_merge_commits: bool) -> String {
+	if hide_merge_commits {
+		"Commit (no merges)".to_string()
+	} else {
+		"Commit".to_string()
+	}
 }
 pub fn file_log_title(
 	file_path: &str,
@@ -1576,6 +1580,24 @@ pub mod commands {
 			CMD_GROUP_LOG,
 		)
 	}
+	pub fn log_toggle_hide_merges(
+		key_config: &SharedKeyConfig,
+		hide_merge_commits: bool,
+	) -> CommandText {
+		let action = if hide_merge_commits {
+			"show merge commits"
+		} else {
+			"hide merge commits"
+		};
+		CommandText::new(
+			format!(
+				"No merges [{}]",
+				key_config.get_hint(key_config.keys.log_hide_merges),
+			),
+			action,
+			CMD_GROUP_LOG,
+		)
+	}
 	pub fn log_find_commit(
 		key_config: &SharedKeyConfig,
 	) -> CommandText {

src/tabs/revlog.rs

@@ -16,8 +16,8 @@ use anyhow::Result;
 use asyncgit::{
 	asyncjob::AsyncSingleJob,
 	sync::{
-		self, filter_commit_by_search, CommitId, LogFilterSearch,
-		LogFilterSearchOptions, RepoPathRef,
+		self, filter_commit_by_search, filter_commits_exclude_merges,
+		CommitId, LogFilterSearch, LogFilterSearchOptions, RepoPathRef,
 	},
 	AsyncBranchesJob, AsyncCommitFilterJob, AsyncGitNotification,
 	AsyncLog, AsyncTags, CommitFilesParams, FetchStatus,
@@ -66,6 +66,7 @@ pub struct Revlog {
 	list: CommitList,
 	git_log: AsyncLog,
 	search: LogSearch,
+	hide_merge_commits: bool,
 	git_tags: AsyncTags,
 	git_local_branches: AsyncSingleJob<AsyncBranchesJob>,
 	git_remote_branches: AsyncSingleJob<AsyncBranchesJob>,
@@ -83,16 +84,14 @@ impl Revlog {
 			repo: env.repo.clone(),
 			queue: env.queue.clone(),
 			commit_details: CommitDetailsComponent::new(env),
-			list: CommitList::new(
-				env,
-				&strings::log_title(&env.key_config),
-			),
+			list: CommitList::new(env, &strings::log_title(false)),
 			git_log: AsyncLog::new(
 				env.repo.borrow().clone(),
 				&env.sender_git,
 				None,
 			),
 			search: LogSearch::Off,
+			hide_merge_commits: false,
 			git_tags: AsyncTags::new(
 				env.repo.borrow().clone(),
 				&env.sender_git,
@@ -404,6 +403,34 @@ impl Revlog {
 	fn can_start_search(&self) -> bool {
 		!self.git_log.is_pending() && !self.is_search_pending()
 	}
+
+	fn can_toggle_hide_merges(&self) -> bool {
+		matches!(self.search, LogSearch::Off) && !self.git_log.is_pending()
+	}
+
+	fn toggle_hide_merge_commits(&mut self) {
+		if !self.can_toggle_hide_merges() {
+			return;
+		}
+
+		self.hide_merge_commits = !self.hide_merge_commits;
+		let filter = if self.hide_merge_commits {
+			Some(filter_commits_exclude_merges())
+		} else {
+			None
+		};
+
+		self.git_log = AsyncLog::new(
+			self.repo.borrow().clone(),
+			&self.sender,
+			filter,
+		);
+		self.git_log.invalidate();
+		self.list.clear();
+		self.list
+			.set_title(strings::log_title(self.hide_merge_commits));
+		let _ = self.git_log.fetch();
+	}
 }
 
 impl DrawableComponent for Revlog {
@@ -575,6 +602,13 @@ impl Component for Revlog {
 					self.queue
 						.push(InternalEvent::OpenLogSearchPopup);
 					return Ok(EventState::Consumed);
+				} else if key_match(
+					k,
+					self.key_config.keys.log_hide_merges,
+				) && self.can_toggle_hide_merges()
+				{
+					self.toggle_hide_merge_commits();
+					return Ok(EventState::Consumed);
 				} else if key_match(
 					k,
 					self.key_config.keys.compare_commits,
@@ -729,6 +763,14 @@ impl Component for Revlog {
 			self.can_start_search(),
 			self.visible || force_all,
 		));
+		out.push(CommandInfo::new(
+			strings::commands::log_toggle_hide_merges(
+				&self.key_config,
+				self.hide_merge_commits,
+			),
+			self.can_toggle_hide_merges(),
+			self.visible || force_all,
+		));
 
 		visibility_blocking(self)
 	}