1 files changed, 23 insertions, 0 deletions
diff --git a/src/exec.zig b/src/exec.zig
index ca48bed1..080d0aea 100644
--- a/src/exec.zig
+++ b/src/exec.zig
@@ -413,9 +413,28 @@ fn spawnTtyWithMount(p: *Pardes, from: usize, v9fs: bool) ?*Pane {
     nt.v9fs_on_spawn = v9fs;
     nt.body.mode = .tty;
     placeNew(p, from, from, free, .shell);
+    if (refusedPlacement(p, free)) {
+        p.reportError(from, "Tty", error.NoPaneRoom);
+        return null;
+    }
     return nt;
 }
 
+/// A pane placeNew found no room for: taken back now, before anything is
+/// logged of it or answered with its serial (it was never announced), so
+/// no `new`/`del` pair and no serial a script was told of is left behind.
+fn refusedPlacement(p: *Pardes, id: usize) bool {
+    if (!p.unplaced.isSet(id)) return false;
+    p.unplaced.unset(id);
+    p.removePane(id, null) catch {};
+    // As sync does for a refused pane: none it squeezed stays under its
+    // minimum.
+    for (0..p.ncol) |c| if (!layout.columnAtMinimums(p, c)) {
+        _ = layout.shareColumn(p, c);
+    };
+    return true;
+}
+
 /// Whether a shell would be started in `dir` and `dir` is not there: asked
 /// only of a host that starts shells, and only of a local path.
 pub fn missingDir(p: *Pardes, dir: []const u8) bool {
@@ -811,6 +830,10 @@ fn runCommand(p: *Pardes, from: usize, line: []const u8) ?usize {
     pane.command_from = winid(p, src);
     echoCommand(p, pane, line);
     placeNew(p, from, from, free, .command);
+    if (refusedPlacement(p, free)) {
+        p.reportError(from, "exec", error.NoPaneRoom);
+        return null;
+    }
     noteRun(p, pane, "run", line);
     return free;
 }