An Edit block cut short through exec is an err, not a msg

An exec write does not fail for what its command says, so an a/c/i text
or { group cut short by a write that ended early was only a msg, easy to
miss. Over 9P, that failure (a truncated write, not a command's) is now
logged as an err record naming exec; the pane still says it.

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

2 files changed, 28 insertions, 1 deletions

diff --git a/src/builtins.zig b/src/builtins.zig
index dfd1e84c..6ca216e3 100644
--- a/src/builtins.zig
+++ b/src/builtins.zig
@@ -946,7 +946,21 @@ pub const Edit = struct {
         var why: sam.Why = .{};
         var said: [260]u8 = undefined;
         const res = sam.run(arena, f.content, ninep_pane.dotOf(c.pane), f.path, c.arg orelse "", &why) catch |err| switch (err) {
-            error.Edit => return c.p.reportFailure(c.id, std.fmt.bufPrint(&said, "Edit: {s}", .{why.text()}) catch "Edit: failed"),
+            error.Edit => {
+                const text = std.fmt.bufPrint(&said, "Edit: {s}", .{why.text()}) catch "Edit: failed";
+                // A block cut short (no `.` line, no `}`) that came over
+                // 9P through an exec, whose write does not fail for what
+                // a command says, is still the write's fault: an err.
+                const cut = std.mem.eql(u8, why.text(), "unmatched `{'") or std.mem.startsWith(u8, why.text(), "a, c or i text not ended");
+                if (cut and c.p.fs.serving and !c.p.fs.no_prompt) {
+                    var rec: [300]u8 = undefined;
+                    pardes.ctlfs.events.notePath(c.p, "err", std.fmt.bufPrint(&rec, "{d} exec: {s}", .{ c.pane.serial, text }) catch "- exec: Edit failed");
+                    c.p.fs.unlogged = true;
+                    defer c.p.fs.unlogged = false;
+                    return c.p.reportFailure(c.id, text);
+                }
+                return c.p.reportFailure(c.id, text);
+            },
             error.OutOfMemory => return c.p.reportError(c.id, "Edit", err),
         };
         if (res.undo != 0) {
diff --git a/src/ninep/tree.zig b/src/ninep/tree.zig
index 54d21da6..27091112 100644
--- a/src/ninep/tree.zig
+++ b/src/ninep/tree.zig
@@ -1547,3 +1547,16 @@ test "an a, c or i text still open when its open closes fails there too and chan
     try testing.expect(th.logHas(p, "not ended by a . line"));
     try testing.expectEqualStrings("abc\n", p.panes[0].?.file.?.content);
 }
+
+test "an a, c or i text cut short through exec is an err in the log, not a msg" {
+    const p = try th.withFile(testing.allocator, "abc\n");
+    defer p.deinit();
+    const exec = Node.of(serialOf(p), .exec);
+    const c = call(p, .{ .tag = 1, .op = .open, .node = exec, .omode = 1 }).reply.handle;
+    _ = call(p, .{ .tag = 2, .op = .write, .node = exec, .handle = c, .data = "Edit $a\nhalf\n" });
+    _ = call(p, .{ .tag = 3, .op = .release, .node = exec, .handle = c, .opened = true });
+    var want: [64]u8 = undefined;
+    try testing.expect(th.logHas(p, try std.fmt.bufPrint(&want, "err {d} exec: Edit: a, c or i text not ended", .{serialOf(p)})));
+    try testing.expect(!th.logHas(p, "msg 1 Edit: a, c or i"));
+    try testing.expectEqualStrings("abc\n", p.panes[0].?.file.?.content);
+}