vim-patch:8.1.0519: cannot save and restore the tag stack

Problem:    Cannot save and restore the tag stack.
Solution:   Add gettagstack() and settagstack(). (Yegappan Lakshmanan,
            closes vim/vim#3604)
https://github.com/vim/vim/commit/f49cc60aa802862c595ff619dccc11271633a94b

1 files changed, 79 insertions, 1 deletions

diff --git a/src/nvim/eval.c b/src/nvim/eval.c
index c7d4e32739..3fb19ad153 100644
--- a/src/nvim/eval.c
+++ b/src/nvim/eval.c
@@ -10404,6 +10404,26 @@ static void f_gettabwinvar(typval_T *argvars, typval_T *rettv, FunPtr fptr)
   getwinvar(argvars, rettv, 1);
 }
 
+/*
+ * "gettagstack()" function
+ */
+    static void
+f_gettagstack(typval_T *argvars, typval_T *rettv, FunPtr fptr)
+{
+    win_T	*wp = curwin;			// default is current window
+
+    tv_dict_alloc_ret(rettv);
+
+    if (argvars[0].v_type != VAR_UNKNOWN)
+    {
+	wp = find_win_by_nr_or_id(&argvars[0]);
+	if (wp == NULL)
+	    return;
+    }
+
+    get_tagstack(wp, rettv->vval.v_dict);
+}
+
 /// Returns information about a window as a dictionary.
 static dict_T *get_win_info(win_T *wp, int16_t tpnr, int16_t winnr)
 {
@@ -15197,6 +15217,64 @@ static void f_settabwinvar(typval_T *argvars, typval_T *rettv, FunPtr fptr)
 }
 
 /*
+ * "settagstack()" function
+ */
+    static void
+f_settagstack(typval_T *argvars, typval_T *rettv, FunPtr fptr)
+{
+    static char *e_invact2 = N_("E962: Invalid action: '%s'");
+    win_T	*wp;
+    dict_T	*d;
+    int		action = 'r';
+
+    rettv->vval.v_number = -1;
+
+    // first argument: window number or id
+    wp = find_win_by_nr_or_id(&argvars[0]);
+    if (wp == NULL)
+	return;
+
+    // second argument: dict with items to set in the tag stack
+    if (argvars[1].v_type != VAR_DICT)
+    {
+	EMSG(_(e_dictreq));
+	return;
+    }
+    d = argvars[1].vval.v_dict;
+    if (d == NULL)
+	return;
+
+    // third argument: action - 'a' for append and 'r' for replace.
+    // default is to replace the stack.
+    if (argvars[2].v_type == VAR_UNKNOWN)
+	action = 'r';
+    else if (argvars[2].v_type == VAR_STRING)
+    {
+	const char *actstr;
+	actstr = tv_get_string_chk(&argvars[2]);
+	if (actstr == NULL)
+	    return;
+	if ((*actstr == 'r' || *actstr == 'a') && actstr[1] == NUL)
+	    action = *actstr;
+	else
+	{
+	    EMSG2(_(e_invact2), actstr);
+	    return;
+	}
+    }
+    else
+    {
+	EMSG(_(e_stringreq));
+	return;
+    }
+
+    if (set_tagstack(wp, d, action) == OK)
+	rettv->vval.v_number = 0;
+    else
+	EMSG(_(e_listreq));
+}
+
+/*
  * "setwinvar()" function
  */
 static void f_setwinvar(typval_T *argvars, typval_T *rettv, FunPtr fptr)
@@ -18197,7 +18275,7 @@ pos_T *var2fpos(const typval_T *const tv, const int dollar_lnum,
  * Return FAIL when conversion is not possible, doesn't check the position for
  * validity.
  */
-static int list2fpos(typval_T *arg, pos_T *posp, int *fnump, colnr_T *curswantp)
+int list2fpos(typval_T *arg, pos_T *posp, int *fnump, colnr_T *curswantp)
 {
   list_T *l;
   long i = 0;