get and a deleted file say what happened: the path, changed <serial> deleted, reloaded

get on a file gone from disk failed with a bare ENOENT; it now says get:
<path>: no such file. A watched file deleted on disk was silent; the pane
keeps its text and says <file> deleted on disk (Save writes it again)
once, logged changed <serial> deleted (only a path the watch has read: a
pane renamed to a name never on disk is not deleted). A get that throws a
dirty buffer's
state away logs changed <serial> reloaded, as the watch's reload does.

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

1 files changed, 11 insertions, 1 deletions

diff --git a/src/file_watch.zig b/src/file_watch.zig
index b262e8ce..71a4680d 100644
--- a/src/file_watch.zig
+++ b/src/file_watch.zig
@@ -60,6 +60,10 @@ pub const Watch = struct {
     kq: c_int = -1,
     serial: u32,
     generation: Generation,
+    /// The path last read while watched (its hash): its going away later is
+    /// a deletion to say, where a path never there (a pane renamed to a new
+    /// name) is not.
+    existed: ?u64 = null,
 };
 
 /// The final slot is the one non-pane watched payload: the active ThemeFile.
@@ -440,7 +444,12 @@ pub fn reloadPane(
     }
 
     if (pane.file) |file| {
-        const bytes = filesystem.read(core, file.path) catch return false;
+        const bytes = filesystem.read(core, file.path) catch |err| {
+            // Gone from under the pane: said once, the text kept.
+            if (err == error.FileNotFound and watched.existed == std.hash.Wyhash.hash(0, file.path)) pardes.panes.File.deleted(core, @intCast(id));
+            return false;
+        };
+        if (watches[id]) |*live| live.existed = std.hash.Wyhash.hash(0, file.path);
         defer core.gpa.free(bytes);
         const hash = std.hash.Wyhash.hash(0, bytes);
         switch (watched.generation) {
@@ -517,6 +526,7 @@ pub fn applyEffect(
         const bytes = filesystem.read(core, file.path) catch return false;
         defer core.gpa.free(bytes);
         watched.generation = .{ .text = std.hash.Wyhash.hash(0, bytes) };
+        watched.existed = std.hash.Wyhash.hash(0, file.path);
         return false;
     };
     return on and watches[id] != null and reloadPane(core, io, watches, id, false);