Hi all,

I came up with two improvements on tab-line-mode:
  1. Suppress-errors...
    It suppresses errors when tab-line-switch-to-prev-tab or
    tab-line-switch-to-next-tab is invoked in the window which has no tabs.
  2. Introduce-a-new-variable... (after #1 patch is applied)
    It introduces a new variable tab-line-switch-cycling which enables cycling tab switch.
These patches are attached.
I sent patches for the first time, any advices, comments, or questions are very welcome.

Best regards,
Katsuyuki