improve(tab-bar-segment): always use the name

No longer use the tab index if no explicit name was set.

test/whale-line-segments-test.el

@@ -706,14 +706,9 @@
         (tab-bar-mode t))
 
     (bydi ((:mock tab-bar--current-tab :return tab)
-           (:mock tab-bar--current-tab-index :return 42)
            (:risky-mock fboundp :with always))
 
-      (should (string= "test-tab" (whale-line-segments--tab-bar--identifier)))
-
-      (setcdr (assoc 'explicit-name tab) nil)
-
-      (should (string= "42" (whale-line-segments--tab-bar--identifier))))))
+      (should (string= "test-tab" (whale-line-segments--tab-bar--identifier))))))
 
 ;;;; VC
 

whale-line-segments.el

@@ -862,20 +862,17 @@ Only consider Dired buffers and file buffers."
 ;;;;; Tab bar
 
 (defun whale-line-segments--tab-bar--identifier ()
-  "Get the identifier of the current tab.
+  "Get the identifier of the current tab."
+  (when-let* ((tab (tab-bar--current-tab))
+              (name (alist-get 'name tab)))
 
-This is either an explicit name or its index."
-  (if-let* ((tab (tab-bar--current-tab))
-            ((alist-get 'explicit-name tab))
-            (name (alist-get 'name tab)))
-      name
-    (number-to-string (tab-bar--current-tab-index))))
+    name))
 
 (defvar whale-line-segments--tab-bar
   '((tab-bar-mode
      ((:propertize (:eval (format " %s " (whale-line-segments--tab-bar--identifier)))
                    face whale-line-highlight))))
-  "Get the name or number of the tab.")
+  "Get the name of the tab.")
 
 (whale-line-create-stateless-segment tab-bar
   :var whale-line-segments--tab-bar