1 files changed, 15 insertions, 0 deletions
diff --git a/src/ninep/tree.zig b/src/ninep/tree.zig
index 60778b9c..d6f4211b 100644
--- a/src/ninep/tree.zig
+++ b/src/ninep/tree.zig
@@ -162,6 +162,9 @@ pub const Open = struct {
     /// answered from it again: bash's `read` takes a chunk, keeps a line and
     /// lseeks back to just past it, and a stream has already moved on.
     replay: ?Replay = null,
+    /// A `name` open has named its pane: one name an open, so a second line
+    /// on it (bash writes `printf 'a\nb\n'` a line at a time) is refused.
+    named: bool = false,
 
     pub const Replay = struct { off: u64, bytes: []u8 };
 
@@ -512,6 +515,7 @@ fn attrOf(p: *Pardes, target: Target) ?Reply.Attr {
         .col => |c| {
             if (layout.columnBySerial(p, c.serial) == null) return null;
             return .{
+                // unreachable: a u32 serial fits node_name (16)
                 .name = if (c.file == .dir) (std.fmt.bufPrint(&p.fs.node_name, "{d}", .{c.serial}) catch unreachable) else c.file.fileName(),
                 .node = Node.ofCol(c.serial, c.file),
                 .dir = c.file == .dir,
@@ -534,6 +538,7 @@ fn attrOf(p: *Pardes, target: Target) ?Reply.Attr {
             const pn = p.panes[id].?;
             if (t.file.inPty() and !pn.isTerminal()) return null;
             return .{
+                // unreachable: a u32 serial fits node_name (16)
                 .name = if (t.file == .dir) (std.fmt.bufPrint(&p.fs.node_name, "{d}", .{t.serial}) catch unreachable) else t.file.fileName(),
                 .node = Node.of(t.serial, t.file),
                 .dir = t.file.isDir(),
@@ -579,6 +584,7 @@ fn topSize(p: *Pardes, f: TopFile) u64 {
             if (p.header_focus) break :focus 0;
             const pn = p.panes[p.active] orelse break :focus 0;
             var digits: [16]u8 = undefined;
+            // unreachable: a u32 serial and a newline fit 16
             break :focus (std.fmt.bufPrint(&digits, "{d}\n", .{pn.serial}) catch unreachable).len;
         },
     };
@@ -688,6 +694,7 @@ fn readdir(p: *Pardes, req: Req, target: Target) Reply {
                         continue;
                     }
                     var buf: [16]u8 = undefined;
+                    // unreachable: a u32 serial fits 16
                     const name = std.fmt.bufPrint(&buf, "{d}", .{serial}) catch unreachable;
                     stageDirent(out, p.gpa, Node.of(serial, .dir), true, name);
                 }
@@ -699,6 +706,7 @@ fn readdir(p: *Pardes, req: Req, target: Target) Reply {
                 }
                 var buf: [16]u8 = undefined;
                 const serial = layout.columnSerial(p, c);
+                // unreachable: a u32 serial fits 16
                 stageDirent(out, p.gpa, Node.ofCol(serial, .dir), true, std.fmt.bufPrint(&buf, "{d}", .{serial}) catch unreachable);
             },
             else => return Reply.fail(req.tag, E.NOTDIR),
@@ -1071,6 +1079,13 @@ fn write(p: *Pardes, req: Req, target: Target) Reply {
         o.pending.clearRetainingCapacity();
         return failText(req.tag, E.INVAL, "a line or Edit block over 1 MiB");
     }
+    if (target == .pane and target.pane.file == .name) {
+        if (o.named or std.mem.count(u8, o.pending.items[0..end], "\n") > 1) {
+            o.pending.clearRetainingCapacity();
+            return failText(req.tag, E.INVAL, "invalid file name: one name a write, on one line");
+        }
+        o.named = true;
+    }
     const whole = p.scratch.allocator().dupe(u8, o.pending.items[0..end]) catch return Reply.fail(req.tag, E.NOMEM);
     const rest = o.pending.items.len - end;
     std.mem.copyForwards(u8, o.pending.items[0..rest], o.pending.items[end..]);