A rename alone does not make a pane dirty

Any rename marked the pane dirty (saved revision one back), while the
guards ask only whether its text was ever edited: /index said dirty for a
pane Exit let go without asking. The name is no edit now, so /index, the
guards and Restore agree; Save writes under the new name all the same.

Co-Authored-By: Claude Opus 5.5 <[email protected]>

5 files changed, 15 insertions, 8 deletions

diff --git a/docs/fs.md b/docs/fs.md
index bcf5dd5b..df1b128c 100644
--- a/docs/fs.md
+++ b/docs/fs.md
@@ -504,7 +504,10 @@ selection, and leaves `look` reading back empty.
 
 `/pane/<n>/name` reads the pane's file name (a terminal's directory) and
 writing it renames the buffer; a relative name resolves against the pane's
-directory. The write is the name and its newline, nothing trimmed: a blank
+directory. A name alone is no edit: the pane's `dirty` stays what its text made it
+(a renamed clean file is still 0, and nothing asks about it at Exit,
+Restore or Del, which ask only about text edited), and `Save` writes it
+under the new name all the same. The write is the name and its newline, nothing trimmed: a blank
 inside a name is taken (`two words.zig`), but one at either end, or a
 control character, is refused, `bad character in file name` (EINVAL), as
 acme refuses a blank (xfid.c:650), rather than quietly cut off. `body` appends on write and replaces on truncating open. A
diff --git a/src/ninep/ctl.zig b/src/ninep/ctl.zig
index 0b1ec194..8cf4f0a8 100644
--- a/src/ninep/ctl.zig
+++ b/src/ninep/ctl.zig
@@ -1417,9 +1417,10 @@ test "get reloads the pane from disk and reports a missing file without losing d
     try testing.expectEqualStrings("from disk\n", pane.file.?.content);
     try testing.expect(!pane_files.dirtyOf(pane));
     try testing.expect(pane.file.?.history.undo_len > 0);
-    // What it had (renamed, so dirty) was thrown away for it: logged.
+    // Renamed but never edited, it was clean: nothing thrown away, nothing
+    // logged as reloaded over edits.
     var reloaded: [32]u8 = undefined;
-    try testing.expect(th.logHas(p, try std.fmt.bufPrint(&reloaded, "changed {d} reloaded\n", .{serial})));
+    try testing.expect(!th.logHas(p, try std.fmt.bufPrint(&reloaded, "changed {d} reloaded\n", .{serial})));
 
     _ = wr(p, Node.of(serial, .name), try std.fmt.bufPrint(&name, "{s}/missing.txt\n", .{directory}));
     _ = wr(p, Node.of(serial, .body), "unsaved\n");
@@ -1440,7 +1441,7 @@ test "exec Save writes the named file through the host" {
     const serial = serialOf(p);
     const pane = p.panes[0].?;
     try testing.expectEqual(Status.ok, wr(p, Node.of(serial, .name), "/tmp/renamed.txt\n").reply.status);
-    try testing.expect(pane_files.dirtyOf(pane));
+    try testing.expect(!pane_files.dirtyOf(pane)); // a name alone is no edit; Save writes all the same
     const saved = wr(p, Node.of(serial, .exec), "Save\n");
     try testing.expectEqual(Status.ok, saved.reply.status);
     try testing.expect(saved.saved);
diff --git a/src/ninep/pane.zig b/src/ninep/pane.zig
index d8329ccc..5f8fc00a 100644
--- a/src/ninep/pane.zig
+++ b/src/ninep/pane.zig
@@ -636,7 +636,9 @@ pub fn nameBuffer(p: *Pardes, id: usize, full: []const u8, preserve_tag: bool) !
             if (pane.tag.own) |own| p.gpa.free(own);
             pane.tag.own = null;
         }
-        f.saved_revision = f.revision -% 1;
+        // A name alone is no edit: dirty stays what the text made it, as
+        // the guards ask only whether it was ever edited, so /index, Exit
+        // and Restore agree. Save writes it under the new name all the same.
         f.watch_after_save = fs.localPath(full) != null;
     }
     if (f.highlights.len > 0) p.tree_sitter_gpa.free(f.highlights);
@@ -1151,7 +1153,7 @@ test "relative names use the file directory and can name a new target" {
     var expected_buf: [4096]u8 = undefined;
     const expected = try std.fmt.bufPrint(&expected_buf, "{s}/created.txt", .{directory});
     try testing.expectEqualStrings(expected, pane.file.?.path);
-    try testing.expect(dirtyOf(pane));
+    try testing.expect(!dirtyOf(pane)); // a name alone is no edit
 }
 
 test "relative names follow a pane/new scratch's session directory and virtual directories" {
diff --git a/test/gui-goldens.txt b/test/gui-goldens.txt
index 01bdfc7c..93e77764 100644
--- a/test/gui-goldens.txt
+++ b/test/gui-goldens.txt
@@ -5,7 +5,7 @@
 05-body-selection 96a158adac982f4141526d10956e19828632edc0f6f60d1161d1353e34797118
 06-tag-focus-selection 94aff8499a6e6f399761ffdd56369d526fbe65232eb21c88addd12973af611aa
 07-prompt-notice 041603b841605b0a9456cbbb9b3e06e219b0a08a58e2d38229e1c81366577a87
-08-wide-glyph-edges 94b0beb7cc2f2a09259f4f7d57999001ef75ed53ea210a65a1510404bd161af9
+08-wide-glyph-edges 4f15245cb2e14f4190940a79c61751bbb6efbf21c1e3ab423fb1469e0466697e
 09-collapsed-focus-tint 1d0e6e4b371bc3b2bba96d9177b91f240fa4bef38c62470dc078fa9feed119ac
 10-tagbottom f7175dfb338b75c5ac3457c8422dc0e352c46d51b2c52533ce32ef143fcf6c6b
 12-multiline-tag ddd7d775a246e91b88f0eff98b6f9bea8aa5d63dbfbe931bd830ccb9086bd5c4
diff --git a/test/panes.zig b/test/panes.zig
index 1988fe16..1ca33053 100644
--- a/test/panes.zig
+++ b/test/panes.zig
@@ -1622,7 +1622,8 @@ test "pane filename drafts commit and cancel without changing body or command ta
         try std.testing.expectEqualStrings(tail, pardes.tagline.curTail(pane));
         while (p.nextEffect()) |effect| try std.testing.expect(std.meta.activeTag(effect) != .save_file);
     }
-    try std.testing.expect(pane.file.?.revision != pane.file.?.saved_revision);
+    // A name alone is no edit: the pane stays clean.
+    try std.testing.expect(pane.file.?.revision == pane.file.?.saved_revision);
 }
 
 test "pane filename grapheme edits and invalid empty commits preserve the buffer" {