1 files changed, 14 insertions, 0 deletions
diff --git a/src/builtins.zig b/src/builtins.zig
index 129dd659..70ca93a1 100644
--- a/src/builtins.zig
+++ b/src/builtins.zig
@@ -1191,6 +1191,20 @@ pub const Incl = struct {
             p.incl.clearRetainingCapacity();
             return p.setMessage(c.id, "Incl: none");
         }
+        // All checked before any is taken: `-` clears, alone; a directory
+        // is absolute (or ~) and there.
+        var check = std.mem.tokenizeAny(u8, typed, " \t");
+        while (check.next()) |dir_word| {
+            var said: [320]u8 = undefined;
+            const shown = dir_word[0..@min(dir_word.len, 200)];
+            if (std.mem.eql(u8, dir_word, "-")) return p.reportFailure(c.id, "Incl: invalid: - clears the list, alone");
+            if (dir_word[0] != '/' and dir_word[0] != '~')
+                return p.reportFailure(c.id, std.fmt.bufPrint(&said, "Incl: invalid directory: {s} is relative", .{shown}) catch "Incl: invalid directory");
+            var home_buf: [4096]u8 = undefined;
+            const expanded = @import("fs.zig").expandHome(dir_word, &home_buf);
+            if (comptime pardes.hosted) if (@import("fs.zig").localPath(expanded)) |local| if (!exec.isDirectory(local))
+                return p.reportFailure(c.id, std.fmt.bufPrint(&said, "Incl: no such directory: {s}", .{shown}) catch "Incl: no such directory");
+        }
         var words = std.mem.tokenizeAny(u8, typed, " \t");
         while (words.next()) |dir_word| {
             var home_buf: [4096]u8 = undefined;