Description:

The global-mode-string is incorrectly right-aligned in the tab-bar when
global-display-line-numbers-mode is enabled.  The issue actually depends
on the order of execution of global-display-line-numbers-mode.  I could
not find an offending commit, so I am not sure for how long this issue
exists.  I am currently debugging the Emacs internals to find the root
cause.

Steps:

1) emacs -Q (master 690f7ac86ad9a9d714b1107d05c5e856a43bb18d)

2) Eval the following to enable global-display-line-numbers-mode:

(progn
  (global-display-line-numbers-mode 1))

3) Eval the following to enable display-time-mode, which at this moment
will be displayed in the mode-line:

(progn
  (setopt display-time-interval 1
          display-time-string-forms '((format-time-string "%d/%m/%Y %H:%M:%S" now)))
  (display-time-mode 1))

4) Eval the following to add global-mode-line to tab-bar, right-aligned:

(progn
  (setopt tab-bar-format '(tab-bar-format-tabs-groups
                           tab-bar-separator
                           tab-bar-format-align-right
                           tab-bar-format-global))
  (tab-bar-mode 1))

Result: the global-mode-line is displayed in the tab-bar, right-aligned,
as expected.

5) Run step 2) again

Result: the global-mode-line is displayed in the tab-bar, right-aligned,
with an incorrect padding on the right. See attached video.