1 files changed, 35 insertions, 5 deletions

diff --git a/src/File.zig b/src/File.zig
index c738ee58..d41007c3 100644
--- a/src/File.zig
+++ b/src/File.zig
@@ -105,6 +105,7 @@ pub const State = struct {
 pub const NodeStep = struct { ranges: []modal.Selection, primary: usize };
 
 pub fn dumpPane(
+    p: *Pardes,
     arena: std.mem.Allocator,
     pane: *const Pane,
     file: *const State,
@@ -114,6 +115,18 @@ pub fn dumpPane(
     origin: []const u8,
     origin_arg: []const u8,
 ) !dump.Pane {
+    const dirty = file.revision != file.saved_revision;
+    const on_disk = onDisk(file.path);
+    // A clean file's text is its file's: read from disk when restored, so
+    // a change made there since is what comes back. Any other is kept, once.
+    const from_disk = file.output == null and !dirty and on_disk;
+    // What an unsaved pane's text was read against: the disk as it is, or,
+    // when a change there was seen already, something it is not.
+    const disk_hash: ?u64 = if (file.output != null or !dirty or !on_disk) null else if (file.disk_newer) |newer| newer +% 1 else blk: {
+        const bytes = filesystem.read(p, file.path) catch break :blk null;
+        defer p.gpa.free(bytes);
+        break :blk std.hash.Wyhash.hash(0, bytes);
+    };
     return .{
         .kind = .file,
         .tag = tag,
@@ -127,10 +140,10 @@ pub fn dumpPane(
             .tree_context = file.tree_context,
             .location_rows = try dumpLocationRows(arena, file.location_rows),
             .path = file.path,
-            .content = file.content,
-            .content_b64 = try dump.encodeBytes(arena, file.content),
-            .dirty = file.revision != file.saved_revision,
-            .on_disk = onDisk(file.path),
+            .content_b64 = if (from_disk) "" else try dump.encodeBytes(arena, file.content),
+            .dirty = dirty,
+            .disk_hash = disk_hash,
+            .on_disk = on_disk,
             .origin = origin,
             .origin_arg = origin_arg,
             .mini_source = if (file.mini) |mini| mini.source else "",
@@ -855,7 +868,16 @@ pub fn restore(p: *Pardes, id: usize, src: dump.Pane) !*Pane {
             saved.content_b64.len > encoded_limit or saved.mini_colors_b64.len > encoded_limit)
             return error.InvalidMini;
     }
-    const content: []u8 = if (saved.content_b64.len > 0)
+    // A clean file's text is read from its file: one changed on disk since
+    // the dump comes back changed, never as the old text marked clean (and
+    // a dump from before, which kept it, is read so too). Gone from disk, the
+    // dump's text if it kept one.
+    const from_disk: ?[]u8 = if (Output.fromWord(saved.origin) == null and !saved.dirty and saved.on_disk and
+        saved.mini_source.len == 0 and filesystem.localPath(saved.path) != null)
+        filesystem.read(p, saved.path) catch null
+    else
+        null;
+    const content: []u8 = if (from_disk) |bytes| bytes else if (saved.content_b64.len > 0)
         try dump.decodeBytes(p.gpa, saved.content_b64)
     else
         try p.gpa.dupe(u8, saved.content);
@@ -923,6 +945,14 @@ pub fn restore(p: *Pardes, id: usize, src: dump.Pane) !*Pane {
     // One never on disk (Config's new file, a name not yet saved) is
     // restored as it was: clean, and nothing deleted.
     if (output == null and saved.on_disk and !onDisk(path)) deleted(p, @intCast(id));
+    // Unsaved, and its file changed on disk since the text was read: said,
+    // and its first Save asks before overwriting the newer file.
+    if (saved.disk_hash) |read_against| if (output == null and onDisk(path)) {
+        if (filesystem.read(p, path)) |bytes| {
+            defer p.gpa.free(bytes);
+            if (std.hash.Wyhash.hash(0, bytes) != read_against) changed(p, @intCast(id), bytes);
+        } else |_| {}
+    };
     return pane;
 }