3 files changed, 49 insertions, 16 deletions

diff --git a/src/nvim/eval.c b/src/nvim/eval.c
index 86333acbef..9f88f1e393 100644
--- a/src/nvim/eval.c
+++ b/src/nvim/eval.c
@@ -10065,7 +10065,7 @@ static void get_qf_loc_list(int is_qf, win_T *wp, typval_T *what_arg,
         dict_T *d = what_arg->vval.v_dict;
 
         if (d != NULL) {
-          get_errorlist_properties(wp, d, rettv->vval.v_dict);
+          qf_get_properties(wp, d, rettv->vval.v_dict);
         }
       } else {
         EMSG(_(e_dictreq));
diff --git a/src/nvim/quickfix.c b/src/nvim/quickfix.c
index 6444661512..bc794addc6 100644
--- a/src/nvim/quickfix.c
+++ b/src/nvim/quickfix.c
@@ -4243,10 +4243,22 @@ static int qf_get_list_from_lines(dict_T *what, dictitem_T *di, dict_T *retdict)
   return status;
 }
 
+// Return the quickfix/location list number with the given identifier.
+// Returns -1 if list is not found.
+static int qf_id2nr(const qf_info_T *const qi, const unsigned qfid)
+{
+  for (int qf_idx = 0; qf_idx < qi->qf_listcount; qf_idx++) {
+    if (qi->qf_lists[qf_idx].qf_id == qfid) {
+      return qf_idx;
+    }
+  }
+  return -1;
+}
+
 /// Return quickfix/location list details (title) as a
 /// dictionary. 'what' contains the details to return. If 'list_idx' is -1,
 /// then current list is used. Otherwise the specified list is used.
-int get_errorlist_properties(win_T *wp, dict_T *what, dict_T *retdict)
+int qf_get_properties(win_T *wp, dict_T *what, dict_T *retdict)
 {
   qf_info_T *qi = &ql_info;
   dictitem_T *di;
@@ -4298,12 +4310,8 @@ int get_errorlist_properties(win_T *wp, dict_T *what, dict_T *retdict)
     if (di->di_tv.v_type == VAR_NUMBER) {
       // For zero, use the current list or the list specifed by 'nr'
       if (di->di_tv.vval.v_number != 0) {
-        for (qf_idx = 0; qf_idx < qi->qf_listcount; qf_idx++) {
-          if (qi->qf_lists[qf_idx].qf_id == di->di_tv.vval.v_number) {
-            break;
-          }
-        }
-        if (qf_idx == qi->qf_listcount) {
+        qf_idx = qf_id2nr(qi, (unsigned)di->di_tv.vval.v_number);
+        if (qf_idx == -1) {
           return FAIL;      // List not found
         }
       }
@@ -4528,12 +4536,8 @@ static int qf_set_properties(qf_info_T *qi, dict_T *what, int action,
   if (!newlist && (di = tv_dict_find(what, S_LEN("id"))) != NULL) {
     // Use the quickfix/location list with the specified id
     if (di->di_tv.v_type == VAR_NUMBER) {
-      for (qf_idx = 0; qf_idx < qi->qf_listcount; qf_idx++) {
-        if (qi->qf_lists[qf_idx].qf_id == di->di_tv.vval.v_number) {
-          break;
-        }
-      }
-      if (qf_idx == qi->qf_listcount) {
+      qf_idx = qf_id2nr(qi, (unsigned)di->di_tv.vval.v_number);
+      if (qf_idx == -1) {
         return FAIL;      // List not found
       }
     } else {
@@ -4565,6 +4569,13 @@ static int qf_set_properties(qf_info_T *qi, dict_T *what, int action,
 
       retval = qf_add_entries(qi, qf_idx, di->di_tv.vval.v_list,
                               title_save, action == ' ' ? 'a' : action);
+      if (action == 'r') {
+        // When replacing the quickfix list entries using
+        // qf_add_entries(), the title is set with a ':' prefix.
+        // Restore the title with the saved title.
+        xfree(qi->qf_lists[qf_idx].qf_title);
+        qi->qf_lists[qf_idx].qf_title = vim_strsave(title_save);
+      }
       xfree(title_save);
     }
   }
diff --git a/src/nvim/testdir/test_quickfix.vim b/src/nvim/testdir/test_quickfix.vim
index 6227095f4f..7c4d1d3b81 100644
--- a/src/nvim/testdir/test_quickfix.vim
+++ b/src/nvim/testdir/test_quickfix.vim
@@ -469,6 +469,19 @@ func s:test_xhelpgrep(cchar)
   " This wipes out the buffer, make sure that doesn't cause trouble.
   Xclose
 
+  if a:cchar == 'l'
+      " When a help window is present, running :lhelpgrep should reuse the
+      " help window and not the current window
+      new | only
+      call g:Xsetlist([], 'f')
+      help index.txt
+      wincmd w
+      lhelpgrep quickfix
+      call assert_equal(1, winnr())
+      call assert_notequal([], getloclist(1))
+      call assert_equal([], getloclist(2))
+  endif
+
   new | only
 
   " Search for non existing help string
@@ -1666,6 +1679,10 @@ func HistoryTest(cchar)
   call assert_equal('  error list 1 of 3; 1 ' . common, res[0])
   call assert_equal('  error list 2 of 3; 2 ' . common, res[1])
   call assert_equal('> error list 3 of 3; 3 ' . common, res[2])
+
+  call g:Xsetlist([], 'f')
+  let l = split(execute(a:cchar . 'hist'), "\n")
+  call assert_equal('No entries', l[0])
 endfunc
 
 func Test_history()
@@ -1844,6 +1861,11 @@ func Xproperty_tests(cchar)
     let l = g:Xgetlist({'items':1})
     call assert_equal(0, len(l.items))
 
+    call g:Xsetlist([], 'r', {'title' : 'TestTitle'})
+    call g:Xsetlist([], 'r', {'items' : [{'filename' : 'F1', 'lnum' : 10, 'text' : 'L10'}]})
+    call g:Xsetlist([], 'r', {'items' : [{'filename' : 'F1', 'lnum' : 10, 'text' : 'L10'}]})
+    call assert_equal('TestTitle', g:Xgetlist({'title' : 1}).title)
+
     " The following used to crash Vim with address sanitizer
     call g:Xsetlist([], 'f')
     call g:Xsetlist([], 'a', {'items' : [{'filename':'F1', 'lnum':10}]})
@@ -1886,10 +1908,10 @@ func Xproperty_tests(cchar)
     call g:Xsetlist([], 'r', l2)
     let newl1=g:Xgetlist({'nr':1,'all':1})
     let newl2=g:Xgetlist({'nr':2,'all':1})
-    call assert_equal(':Fruits', newl1.title)
+    call assert_equal('Fruits', newl1.title)
     call assert_equal(['Fruits'], newl1.context)
     call assert_equal('Line20', newl1.items[0].text)
-    call assert_equal(':Colors', newl2.title)
+    call assert_equal('Colors', newl2.title)
     call assert_equal(['Colors'], newl2.context)
     call assert_equal('Line10', newl2.items[0].text)
     call g:Xsetlist([], 'f')