patch 8.2.0077: settagstack() cannot truncate at current indexv8.2.0077

Problem:    settagstack() cannot truncate at current index.
Solution:   Add the "t" action. (Yegappan Lakshmanan, closes #5417)

1 files changed, 25 insertions, 6 deletions

diff --git a/src/tag.c b/src/tag.c
index c00f5fb723..4f897fa607 100644
--- a/src/tag.c
+++ b/src/tag.c
@@ -4224,13 +4224,16 @@ tagstack_set_curidx(win_T *wp, int curidx)
 
 /*
  * Set the tag stack entries of the specified window.
- * 'action' is set to either 'a' for append or 'r' for replace.
+ * 'action' is set to one of:
+ *	'a' for append
+ *	'r' for replace
+ *	't' for truncate
  */
     int
 set_tagstack(win_T *wp, dict_T *d, int action)
 {
     dictitem_T	*di;
-    list_T	*l;
+    list_T	*l = NULL;
 
 #ifdef FEAT_EVAL
     // not allowed to alter the tag stack entries from inside tagfunc
@@ -4249,16 +4252,32 @@ set_tagstack(win_T *wp, dict_T *d, int action)
 	    return FAIL;
 	}
 	l = di->di_tv.vval.v_list;
+    }
 
-	if (action == 'r')
+    if ((di = dict_find(d, (char_u *)"curidx", -1)) != NULL)
+	tagstack_set_curidx(wp, (int)tv_get_number(&di->di_tv) - 1);
+
+    if (action == 't')		    // truncate the stack
+    {
+	taggy_T	*tagstack = wp->w_tagstack;
+	int	tagstackidx = wp->w_tagstackidx;
+	int	tagstacklen = wp->w_tagstacklen;
+	// delete all the tag stack entries above the current entry
+	while (tagstackidx < tagstacklen)
+	    tagstack_clear_entry(&tagstack[--tagstacklen]);
+	wp->w_tagstacklen = tagstacklen;
+    }
+
+    if (l != NULL)
+    {
+	if (action == 'r')		// replace the stack
 	    tagstack_clear(wp);
 
 	tagstack_push_items(wp, l);
+	// set the current index after the last entry
+	wp->w_tagstackidx = wp->w_tagstacklen;
     }
 
-    if ((di = dict_find(d, (char_u *)"curidx", -1)) != NULL)
-	tagstack_set_curidx(wp, (int)tv_get_number(&di->di_tv) - 1);
-
     return OK;
 }
 #endif