vim-patch:9.1.0572: cannot specify tab page closing behaviour (#29682)

Problem:  cannot specify tab page closing behaviour
          (Gianluca Pacchiella)
Solution: Add the 'tabclose' option (LemonBoy).

fixes: vim/vim#5967
closes: vim/vim#15204

https://github.com/vim/vim/commit/5247b0b92e191a046b034171a3b34031e317735f

Co-authored-by: LemonBoy <thatlemon@gmail.com>

4 files changed, 61 insertions, 7 deletions

diff --git a/src/nvim/option_vars.h b/src/nvim/option_vars.h
index 3326c0879a..b6b307befb 100644
--- a/src/nvim/option_vars.h
+++ b/src/nvim/option_vars.h
@@ -694,7 +694,6 @@ EXTERN unsigned tpf_flags;      ///< flags from 'termpastefilter'
 EXTERN char *p_tfu;             ///< 'tagfunc'
 EXTERN char *p_spc;             ///< 'spellcapcheck'
 EXTERN char *p_spf;             ///< 'spellfile'
-EXTERN char *p_spk;             ///< 'splitkeep'
 EXTERN char *p_spl;             ///< 'spelllang'
 EXTERN char *p_spo;             ///< 'spelloptions'
 EXTERN unsigned spo_flags;
@@ -711,7 +710,12 @@ EXTERN unsigned swb_flags;
 #define SWB_NEWTAB              0x008
 #define SWB_VSPLIT              0x010
 #define SWB_USELAST             0x020
+EXTERN char *p_spk;             ///< 'splitkeep'
 EXTERN char *p_syn;             ///< 'syntax'
+EXTERN char *p_tcl;             ///< 'tabclose'
+EXTERN unsigned tcl_flags;      ///< flags from 'tabclose'
+#define TCL_LEFT                0x001
+#define TCL_USELAST             0x002
 EXTERN OptInt p_ts;             ///< 'tabstop'
 EXTERN int p_tbs;               ///< 'tagbsearch'
 EXTERN char *p_tc;              ///< 'tagcase'
diff --git a/src/nvim/options.lua b/src/nvim/options.lua
index 6e317a426c..6345ef5ada 100644
--- a/src/nvim/options.lua
+++ b/src/nvim/options.lua
@@ -8507,6 +8507,30 @@ return {
       varname = 'p_syn',
     },
     {
+      abbreviation = 'tcl',
+      cb = 'did_set_tabclose',
+      defaults = { if_true = '' },
+      deny_duplicates = true,
+      desc = [=[
+        This option controls the behavior when closing tab pages (e.g., using
+        |:tabclose|).  When empty Vim goes to the next (right) tab page.
+
+        Possible values (comma-separated list):
+           left		If included, go to the previous tab page instead of
+        		the next one.
+           uselast	If included, go to the previously used tab page if
+        		possible.  This option takes precedence over the
+        		others.
+      ]=],
+      expand_cb = 'expand_set_tabclose',
+      full_name = 'tabclose',
+      list = 'onecomma',
+      scope = { 'global' },
+      short_desc = N_('which tab page to focus when closing a tab'),
+      type = 'string',
+      varname = 'p_tcl',
+    },
+    {
       abbreviation = 'tal',
       cb = 'did_set_tabline',
       defaults = { if_true = '' },
diff --git a/src/nvim/optionstr.c b/src/nvim/optionstr.c
index 1a4c142fdd..8e853b6ee0 100644
--- a/src/nvim/optionstr.c
+++ b/src/nvim/optionstr.c
@@ -98,11 +98,13 @@ static char *(p_ssop_values[]) = { "buffers", "winpos", "resize", "winsize", "lo
                                    "options", "help", "blank", "globals", "slash", "unix", "sesdir",
                                    "curdir", "folds", "cursor", "tabpages", "terminal", "skiprtp",
                                    NULL };
-// Keep in sync with SWB_ flags in option_defs.h
+// Keep in sync with SWB_ flags in option_vars.h
 static char *(p_swb_values[]) = { "useopen", "usetab", "split", "newtab", "vsplit", "uselast",
                                   NULL };
 static char *(p_spk_values[]) = { "cursor", "screen", "topline", NULL };
 static char *(p_tc_values[]) = { "followic", "ignore", "match", "followscs", "smart", NULL };
+// Keep in sync with TCL_ flags in option_vars.h
+static char *(p_tcl_values[]) = { "left", "uselast", NULL };
 static char *(p_ve_values[]) = { "block", "insert", "all", "onemore", "none", "NONE", NULL };
 // Note: Keep this in sync with check_opt_wim()
 static char *(p_wim_values[]) = { "full", "longest", "list", "lastused", NULL };
@@ -169,6 +171,7 @@ void didset_string_options(void)
   opt_strings_flags(p_tpf, p_tpf_values, &tpf_flags, true);
   opt_strings_flags(p_ve, p_ve_values, &ve_flags, true);
   opt_strings_flags(p_swb, p_swb_values, &swb_flags, true);
+  opt_strings_flags(p_tcl, p_tcl_values, &tcl_flags, true);
   opt_strings_flags(p_wop, p_wop_values, &wop_flags, true);
   opt_strings_flags(p_cb, p_cb_values, &cb_flags, true);
 }
@@ -2207,6 +2210,21 @@ int expand_set_switchbuf(optexpand_T *args, int *numMatches, char ***matches)
                                matches);
 }
 
+/// The 'tabclose' option is changed.
+const char *did_set_tabclose(optset_T *args FUNC_ATTR_UNUSED)
+{
+  return did_set_opt_flags(p_tcl, p_tcl_values, &tcl_flags, true);
+}
+
+int expand_set_tabclose(optexpand_T *args, int *numMatches, char ***matches)
+{
+  return expand_set_opt_string(args,
+                               p_tcl_values,
+                               ARRAY_SIZE(p_tcl_values) - 1,
+                               numMatches,
+                               matches);
+}
+
 /// The 'tabline' option is changed.
 const char *did_set_tabline(optset_T *args)
 {
diff --git a/src/nvim/window.c b/src/nvim/window.c
index 9203dd1bdb..132bf9ee60 100644
--- a/src/nvim/window.c
+++ b/src/nvim/window.c
@@ -3456,14 +3456,22 @@ static frame_T *win_altframe(win_T *win, tabpage_T *tp)
 // Return the tabpage that will be used if the current one is closed.
 static tabpage_T *alt_tabpage(void)
 {
-  // Use the next tab page if possible.
-  if (curtab->tp_next != NULL) {
-    return curtab->tp_next;
+  // Use the last accessed tab page, if possible.
+  if ((tcl_flags & TCL_USELAST) && valid_tabpage(lastused_tabpage)) {
+    return lastused_tabpage;
   }
 
-  // Find the last but one tab page.
+  // Use the previous tab page, if possible.
+  bool forward = curtab->tp_next != NULL
+                 && ((tcl_flags & TCL_LEFT) == 0 || curtab == first_tabpage);
+
   tabpage_T *tp;
-  for (tp = first_tabpage; tp->tp_next != curtab; tp = tp->tp_next) {}
+  if (forward) {
+    tp = curtab->tp_next;
+  } else {
+    for (tp = first_tabpage; tp->tp_next != curtab; tp = tp->tp_next) {}
+  }
+
   return tp;
 }