1 files changed, 63 insertions, 23 deletions

diff --git a/src/File.zig b/src/File.zig
index 522d4bd6..0f1579b2 100644
--- a/src/File.zig
+++ b/src/File.zig
@@ -32,8 +32,58 @@ pub const Snapshot = struct {
     cur_row: i32,
     cur_col: i32,
     vsel: Text.CharSel,
+    /// The name the text had then (owned), and whether and as what it was
+    /// saved under it: an undo across a load into the pane under another
+    /// name (Get file, Edit's e) puts the name back with the text, and the
+    /// dirty state that went with them, as acme's undo does.
+    path: ?[]u8 = null,
+    clean: bool = false,
+    saved_hash: ?u64 = null,
+    saved_len: ?usize = null,
+
+    fn deinit(s: Snapshot, gpa: std.mem.Allocator) void {
+        gpa.free(s.content);
+        if (s.path) |path| gpa.free(path);
+    }
 };
 
+/// The pane's text, place and name now, for an undo or redo step.
+fn snapshotOf(gpa: std.mem.Allocator, pane: *const Pane, f: *const State) ?Snapshot {
+    const content = gpa.dupe(u8, f.content) catch return null;
+    const path = gpa.dupe(u8, f.path) catch {
+        gpa.free(content);
+        return null;
+    };
+    return .{
+        .content = content,
+        .cur_row = pane.body.cur_row,
+        .cur_col = pane.body.cur_col,
+        .vsel = pane.body.vsel,
+        .path = path,
+        .clean = f.revision == f.saved_revision,
+        .saved_hash = f.saved_hash,
+        .saved_len = f.saved_len,
+    };
+}
+
+/// After a step's text went in: if it was under another name, that name
+/// back, and the step's saved state with it (Get file, Edit's e).
+fn restoreName(p: *Pardes, pane: *Pane, f: *State, snap: Snapshot) void {
+    defer if (snap.path) |path| p.gpa.free(path);
+    const path = snap.path orelse return;
+    if (std.mem.eql(u8, path, f.path)) return;
+    const id = for (p.panes, 0..) |slot, i| {
+        if (slot == pane) break i;
+    } else return;
+    pardes.ctlfs.pane.nameBuffer(p, id, path, false) catch return;
+    f.saved_hash = snap.saved_hash;
+    f.saved_len = snap.saved_len;
+    f.saved_revision = if (snap.clean) f.revision else f.revision -% 1;
+    f.disk_newer = null;
+    f.disk_newer_warned = false;
+    if (filesystem.localPath(path) != null) p.emit(.{ .watch = .{ .pane = @intCast(id), .on = true } });
+}
+
 pub const History = struct {
     undo: [limits.undo_max]Snapshot = undefined,
     undo_len: usize = 0,
@@ -1016,8 +1066,8 @@ pub fn deinit(p: *Pardes, pane: *Pane, file: *State) void {
     for (file.node_history.items) |step| p.gpa.free(step.ranges);
     file.node_history.deinit(p.gpa);
     if (ntwins > 0) return;
-    for (file.history.undo[0..file.history.undo_len]) |snap| p.gpa.free(snap.content);
-    for (file.history.redo[0..file.history.redo_len]) |snap| p.gpa.free(snap.content);
+    for (file.history.undo[0..file.history.undo_len]) |snap| snap.deinit(p.gpa);
+    for (file.history.redo[0..file.history.redo_len]) |snap| snap.deinit(p.gpa);
     p.gpa.destroy(file.history);
 }
 
@@ -1340,7 +1390,7 @@ pub fn restoreSnap(pane: *Pane, f: *State, snap: Snapshot) void {
 
 fn pushHistory(gpa: std.mem.Allocator, slots: []Snapshot, len: *usize, snap: Snapshot) void {
     if (len.* == slots.len) {
-        gpa.free(slots[0].content);
+        slots[0].deinit(gpa);
         std.mem.copyForwards(Snapshot, slots[0 .. slots.len - 1], slots[1..]);
         len.* -= 1;
     }
@@ -1351,15 +1401,13 @@ fn pushHistory(gpa: std.mem.Allocator, slots: []Snapshot, len: *usize, snap: Sna
 pub fn pushUndo(p: *Pardes, pane: *Pane) void {
     const f = if (pane.file) |*file| file else return;
     const history = f.history;
-    if (history.undo_len > 0 and std.mem.eql(u8, history.undo[history.undo_len - 1].content, f.content)) return;
-    const snap: Snapshot = .{
-        .content = p.gpa.dupe(u8, f.content) catch return,
-        .cur_row = pane.body.cur_row,
-        .cur_col = pane.body.cur_col,
-        .vsel = pane.body.vsel,
-    };
+    if (history.undo_len > 0) {
+        const last = history.undo[history.undo_len - 1];
+        if (std.mem.eql(u8, last.content, f.content) and std.mem.eql(u8, last.path orelse f.path, f.path)) return;
+    }
+    const snap = snapshotOf(p.gpa, pane, f) orelse return;
     pushHistory(p.gpa, &history.undo, &history.undo_len, snap);
-    for (history.redo[0..history.redo_len]) |item| p.gpa.free(item.content);
+    for (history.redo[0..history.redo_len]) |item| item.deinit(p.gpa);
     history.redo_len = 0;
 }
 
@@ -1367,16 +1415,12 @@ pub fn undo(p: *Pardes, pane: *Pane) void {
     const f = if (pane.file) |*file| file else return;
     const history = f.history;
     if (history.undo_len == 0) return;
-    const current: Snapshot = .{
-        .content = p.gpa.dupe(u8, f.content) catch return,
-        .cur_row = pane.body.cur_row,
-        .cur_col = pane.body.cur_col,
-        .vsel = pane.body.vsel,
-    };
+    const current = snapshotOf(p.gpa, pane, f) orelse return;
     pushHistory(p.gpa, &history.redo, &history.redo_len, current);
     history.undo_len -= 1;
     const previous = history.undo[history.undo_len];
     setContent(p, f, previous.content);
+    restoreName(p, pane, f, previous);
     restoreSnap(pane, f, previous);
 }
 
@@ -1384,16 +1428,12 @@ pub fn redo(p: *Pardes, pane: *Pane) void {
     const f = if (pane.file) |*file| file else return;
     const history = f.history;
     if (history.redo_len == 0) return;
-    const current: Snapshot = .{
-        .content = p.gpa.dupe(u8, f.content) catch return,
-        .cur_row = pane.body.cur_row,
-        .cur_col = pane.body.cur_col,
-        .vsel = pane.body.vsel,
-    };
+    const current = snapshotOf(p.gpa, pane, f) orelse return;
     pushHistory(p.gpa, &history.undo, &history.undo_len, current);
     history.redo_len -= 1;
     const next = history.redo[history.redo_len];
     setContent(p, f, next.content);
+    restoreName(p, pane, f, next);
     restoreSnap(pane, f, next);
 }