2 files changed, 29 insertions, 0 deletions
diff --git a/src/File.zig b/src/File.zig
index d41007c3..4fac0073 100644
--- a/src/File.zig
+++ b/src/File.zig
@@ -953,6 +953,16 @@ pub fn restore(p: *Pardes, id: usize, src: dump.Pane) !*Pane {
             if (std.hash.Wyhash.hash(0, bytes) != read_against) changed(p, @intCast(id), bytes);
         } else |_| {}
     };
+    // An older dump says nothing of what the text was read against: its
+    // first Save asks, as for a file changed on disk, rather than guess.
+    if (saved.dirty and saved.disk_hash == null and output == null and onDisk(path)) {
+        if (filesystem.read(p, path)) |bytes| {
+            defer p.gpa.free(bytes);
+            const f = &pane.file.?;
+            f.disk_newer = std.hash.Wyhash.hash(0, bytes);
+            f.disk_newer_warned = false;
+        } else |_| {}
+    }
     return pane;
 }
 
diff --git a/src/ninep/ctl.zig b/src/ninep/ctl.zig
index 16fbabb4..554333bb 100644
--- a/src/ninep/ctl.zig
+++ b/src/ninep/ctl.zig
@@ -4409,3 +4409,22 @@ test "a command or a terminal refused for room is refused before anything is log
         p.update(.{ .resize = .{ .cols = 80, .rows = 24 } });
     }
 }
+
+test "an unsaved pane from a dump that says nothing of its disk asks at its first Save" {
+    if (comptime !pardes.hosted) return;
+    const gpa = testing.allocator;
+    var tmp = testing.tmpDir(.{});
+    defer tmp.cleanup();
+    try tmp.dir.writeFile(testing.io, .{ .sub_path = "old.txt", .data = "disk\n" });
+    var dir_buf: [4096]u8 = undefined;
+    const dir = dir_buf[0..try tmp.dir.realPath(testing.io, &dir_buf)];
+    var path_buf: [4200]u8 = undefined;
+    const path = try std.fmt.bufPrint(&path_buf, "{s}/old.txt", .{dir});
+    const p = try withFile(gpa, "x\n");
+    defer p.deinit();
+    const id = p.freeSlot().?;
+    const pane = try pardes.panes.File.restore(p, id, .{ .kind = .file, .tag = "", .body = "", .file = .{ .path = path, .content = "unsaved\n", .dirty = true } });
+    try testing.expect(pane.file.?.disk_newer != null);
+    pardes.exec.saveFile(p, id);
+    try testing.expect(th.logHas(p, "modified on disk since read (Save again to overwrite)"));
+}