fish: Print extended help when the user types an unknown command first.

$ guestfish /tmp/disk.img
/tmp/disk.img: unknown command
Did you mean to open a disk image?  guestfish -a disk.img
For a list of commands:             guestfish -h
For complete documentation:         man guestfish

1 files changed, 2 insertions, 0 deletions

diff --git a/src/generator.ml b/src/generator.ml
index f206be1b..416a66fd 100755
--- a/src/generator.ml
+++ b/src/generator.ml
@@ -7403,6 +7403,8 @@ and generate_fish_cmds () =
   ) all_functions;
   pr "    {\n";
   pr "      fprintf (stderr, _(\"%%s: unknown command\\n\"), cmd);\n";
+  pr "      if (command_num == 1)\n";
+  pr "        extended_help_message ();\n";
   pr "      return -1;\n";
   pr "    }\n";
   pr "  return 0;\n";