only offer edit on head revision, open older revisions as tempfile

CHANGELOG.md

@@ -15,6 +15,7 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 * open the external editor from the status diff view [[@WaterWhisperer](https://github.com/WaterWhisperer)] ([#2805](https://github.com/gitui-org/gitui/issues/2805))
 * automatically convert spaces to dashes when creating or renaming a branch [[@pbouillon]](https//pbouillon.github.io)] ([#2916](https://github.com/gitui-org/gitui/pull/2916))
 * support rewording non-HEAD commits when `commit.gpgsign` is enabled (gpg format only) [[@guerinoni](https://github.com/guerinoni)] ([#2959](https://github.com/gitui-org/gitui/pull/2959))
+* in the revision file tree `edit [e]` is now only offered on the head revision, older revisions offer `open [o]` which dumps that revision of the file into a temporary file and opens it ([#2147](https://github.com/gitui-org/gitui/issues/2147))
 
 ### Fixes
 * crash when opening submodule ([#2895](https://github.com/gitui-org/gitui/issues/2895))

Cargo.toml

@@ -59,6 +59,7 @@ shellexpand = "3.1"
 simplelog = { version = "0.12", default-features = false }
 struct-patch = "0.10"
 syntect = { version = "5.3", default-features = false, features = ["default-syntaxes", "default-themes", "html", "parsing", "plist-load"] }
+tempfile = "3"
 two-face = { version = "0.4.4", default-features = false }
 unicode-segmentation = "1.12"
 unicode-truncate = "2.0"

src/components/revision_files.rs

@@ -17,7 +17,8 @@ use anyhow::Result;
 use asyncgit::{
 	asyncjob::AsyncSingleJob,
 	sync::{
-		get_commit_info, CommitId, CommitInfo, RepoPathRef, TreeFile,
+		get_commit_info, get_head, tree_file_content, CommitId,
+		CommitInfo, RepoPathRef, TreeFile,
 	},
 	AsyncGitNotification, AsyncTreeFilesJob,
 };
@@ -54,6 +55,7 @@ pub struct RevisionFilesComponent {
 	scroll: VerticalScroll,
 	visible: bool,
 	revision: Option<CommitInfo>,
+	revision_is_head: bool,
 	focus: Focus,
 	key_config: SharedKeyConfig,
 	select_file: Option<PathBuf>,
@@ -76,6 +78,7 @@ impl RevisionFilesComponent {
 				env.sender_git.clone(),
 			),
 			revision: None,
+			revision_is_head: false,
 			focus: Focus::Tree,
 			key_config: env.key_config.clone(),
 			repo: env.repo.clone(),
@@ -100,6 +103,9 @@ impl RevisionFilesComponent {
 				Some(get_commit_info(&self.repo.borrow(), &commit)?);
 		}
 
+		self.revision_is_head = get_head(&self.repo.borrow())
+			.is_ok_and(|head| head == commit);
+
 		Ok(())
 	}
 
@@ -265,6 +271,54 @@ impl RevisionFilesComponent {
 		})
 	}
 
+	/// dumps the selected file at the currently viewed revision into a
+	/// temporary file and opens that in the external editor
+	fn open_file_revision(&self) -> Result<()> {
+		let Some(file_path) = self.selected_file_path_with_prefix()
+		else {
+			return Ok(());
+		};
+
+		let path = Path::new(&file_path);
+
+		let Some(file) = self
+			.files
+			.as_ref()
+			.and_then(|files| files.iter().find(|f| f.path == path))
+		else {
+			return Ok(());
+		};
+
+		let content = tree_file_content(&self.repo.borrow(), file)?;
+
+		let file_name = path
+			.file_name()
+			.map(|name| name.to_string_lossy().to_string())
+			.unwrap_or_default();
+
+		let temp_file = tempfile::Builder::new()
+			.prefix(&format!("gitui-{}-", self.revision_short_id()))
+			.suffix(&format!("-{file_name}"))
+			.tempfile()?
+			.into_temp_path()
+			.keep()?;
+
+		std::fs::write(&temp_file, content)?;
+
+		self.queue.push(InternalEvent::OpenExternalEditor(Some(
+			temp_file.to_string_lossy().to_string(),
+		)));
+
+		Ok(())
+	}
+
+	fn revision_short_id(&self) -> String {
+		self.revision
+			.as_ref()
+			.map(|commit| commit.id.get_short_string())
+			.unwrap_or_default()
+	}
+
 	fn selection_changed(&mut self) {
 		//TODO: retrieve TreeFile from tree datastructure
 		if let Some(file) = self.selected_file_path_with_prefix() {
@@ -437,11 +491,21 @@ impl Component for RevisionFilesComponent {
 				)
 				.order(order::NAV),
 			);
-			out.push(CommandInfo::new(
-				strings::commands::edit_item(&self.key_config),
-				self.tree.selected_file().is_some(),
-				true,
-			));
+			if self.revision_is_head {
+				out.push(CommandInfo::new(
+					strings::commands::edit_item(&self.key_config),
+					self.tree.selected_file().is_some(),
+					true,
+				));
+			} else {
+				out.push(CommandInfo::new(
+					strings::commands::open_file_revision(
+						&self.key_config,
+					),
+					self.tree.selected_file().is_some(),
+					true,
+				));
+			}
 			out.push(
 				CommandInfo::new(
 					strings::commands::open_file_history(
@@ -516,9 +580,23 @@ impl Component for RevisionFilesComponent {
 					self.open_finder();
 					return Ok(EventState::Consumed);
 				}
+			} else if key_match(
+				key,
+				self.key_config.keys.open_file_revision,
+			) {
+				if !self.revision_is_head {
+					try_or_popup!(
+						self,
+						"failed to open file revision:",
+						self.open_file_revision()
+					);
+					return Ok(EventState::Consumed);
+				}
 			} else if key_match(key, self.key_config.keys.edit_file) {
-				if let Some(file) =
-					self.selected_file_path_with_prefix()
+				if let Some(file) = self
+					.revision_is_head
+					.then(|| self.selected_file_path_with_prefix())
+					.flatten()
 				{
 					//Note: switch to status tab so its clear we are
 					// not altering a file inside a revision here

src/keys/key_list.rs

@@ -70,6 +70,7 @@ pub struct KeysList {
 	pub blame: GituiKeyEvent,
 	pub file_history: GituiKeyEvent,
 	pub edit_file: GituiKeyEvent,
+	pub open_file_revision: GituiKeyEvent,
 	pub status_stage_all: GituiKeyEvent,
 	pub status_reset_item: GituiKeyEvent,
 	pub status_ignore_file: GituiKeyEvent,
@@ -168,6 +169,7 @@ impl Default for KeysList {
 			blame: GituiKeyEvent::new(KeyCode::Char('B'),  KeyModifiers::SHIFT),
 			file_history: GituiKeyEvent::new(KeyCode::Char('H'),  KeyModifiers::SHIFT),
 			edit_file: GituiKeyEvent::new(KeyCode::Char('e'),  KeyModifiers::empty()),
+			open_file_revision: GituiKeyEvent::new(KeyCode::Char('o'),  KeyModifiers::empty()),
 			status_stage_all: GituiKeyEvent::new(KeyCode::Char('a'),  KeyModifiers::empty()),
 			status_reset_item: GituiKeyEvent::new(KeyCode::Char('D'),  KeyModifiers::SHIFT),
 			diff_reset_lines: GituiKeyEvent::new(KeyCode::Char('d'),  KeyModifiers::empty()),

src/strings.rs

@@ -1232,6 +1232,18 @@ pub mod commands {
 			CMD_GROUP_CHANGES,
 		)
 	}
+	pub fn open_file_revision(
+		key_config: &SharedKeyConfig,
+	) -> CommandText {
+		CommandText::new(
+			format!(
+				"Open [{}]",
+				key_config.get_hint(key_config.keys.open_file_revision),
+			),
+			"open the selected revision of the file in an external editor (as a temporary file)",
+			CMD_GROUP_CHANGES,
+		)
+	}
 	pub fn stage_item(key_config: &SharedKeyConfig) -> CommandText {
 		CommandText::new(
 			format!(