goto_tab now maps numbers larger than the last tab to the last tab

Fixes #2291

docs/changelog.rst

@@ -33,6 +33,9 @@ To update |kitty|, :doc:`follow the instructions <binary>`.
 
 - Fix a segfault when using :option:`kitty --debug-config` with maps (:iss:`2270`)
 
+- ``goto_tab`` now maps numbers larger than the last tab to the last tab
+  (:iss:`2291`)
+
 
 0.15.1 [2019-12-21]
 --------------------

kitty/config_data.py

@@ -144,7 +144,8 @@ For example::
             _('Tab management'), '',
             _('''\
 You can also create shortcuts to go to specific tabs, with 1 being the first
-tab, 2 the second tab and -1 being the previously active tab::
+tab, 2 the second tab and -1 being the previously active tab, and any number
+larger than the last tab being the last tab::
 
     map ctrl+alt+1 goto_tab 1
     map ctrl+alt+2 goto_tab 2

kitty/tabs.py

@@ -560,9 +560,11 @@ class TabManager:  # {{{
             self.set_active_tab_idx((self.active_tab_idx + len(self.tabs) + delta) % len(self.tabs))
 
     def goto_tab(self, tab_num):
-        if 0 <= tab_num < len(self.tabs):
+        if tab_num >= len(self.tabs):
+            tab_num = max(0, len(self.tabs) - 1)
+        if tab_num >= 0:
             self.set_active_tab_idx(tab_num)
-        elif tab_num < 0:
+        else:
             try:
                 old_active_tab_id = self.active_tab_history[tab_num]
             except IndexError: