vim-patch:8.1.0523: opening window from quickfix leaves empty buffer behind

Problem:    Opening window from quickfix leaves empty buffer behind.
Solution:   Add qf_jump_newwin(). (Yegappan Lakshmanan, closes vim/vim#2574)
b244373bec

Close https://github.com/neovim/neovim/pull/12855

src/nvim/quickfix.c

@@ -2453,12 +2453,13 @@ static void win_set_loclist(win_T *wp, qf_info_T *qi)
   qi->qf_refcount++;
 }
 
-/// Find a help window or open one.
+/// Find a help window or open one. If 'newwin' is true, then open a new help
-static int jump_to_help_window(qf_info_T *qi, int *opened_window)
+/// window.
+static int jump_to_help_window(qf_info_T *qi, bool newwin, int *opened_window)
 {
   win_T *wp = NULL;
 
-  if (cmdmod.tab != 0) {
+  if (cmdmod.tab != 0 || newwin) {
     wp = NULL;
   } else {
     wp = qf_find_help_win();
@@ -2476,8 +2477,10 @@ static int jump_to_help_window(qf_info_T *qi, int *opened_window)
       flags |= WSP_TOP;
     }
 
-    if (IS_LL_STACK(qi)) {
+    // If the user asks to open a new window, then copy the location list.
-      flags |= WSP_NEWLOC;  // don't copy the location list
+    // Otherwise, don't copy the location list.
+    if (IS_LL_STACK(qi) && !newwin) {
+      flags |= WSP_NEWLOC;
     }
 
     if (win_split(0, flags) == FAIL) {
@@ -2490,8 +2493,10 @@ static int jump_to_help_window(qf_info_T *qi, int *opened_window)
       win_setheight((int)p_hh);
     }
 
-    if (IS_LL_STACK(qi)) {  // not a quickfix list
+    // When using location list, the new window should use the supplied
-      // The new window should use the supplied location list
+    // location list. If the user asks to open a new window, then the new
+    // window will get a copy of the location list.
+    if (IS_LL_STACK(qi) && !newwin) {
       win_set_loclist(curwin, qi);
     }
   }
@@ -2652,14 +2657,19 @@ static void qf_goto_win_with_qfl_file(int qf_fnum)
 
 // Find a suitable window for opening a file (qf_fnum) from the
 // quickfix/location list and jump to it.  If the file is already opened in a
-// window, jump to it. Otherwise open a new window to display the file. This is
+// window, jump to it. Otherwise open a new window to display the file. If
-// called from either a quickfix or a location list window.
+// 'newwin' is true, then always open a new window. This is called from either
-static int qf_jump_to_usable_window(int qf_fnum, int *opened_window)
+// a quickfix or a location list window.
+static int qf_jump_to_usable_window(int qf_fnum, bool newwin,
+                                    int *opened_window)
 {
   win_T       *usable_win_ptr = NULL;
   bool usable_win = false;
 
-  qf_info_T *ll_ref = curwin->w_llist_ref;
+  // If opening a new window, then don't use the location list referred by
+  // the current window.  Otherwise two windows will refer to the same
+  // location list.
+  qf_info_T *ll_ref = newwin ? NULL : curwin->w_llist_ref;
   if (ll_ref != NULL) {
     // Find a non-quickfix window with this location list
     usable_win_ptr = qf_find_win_with_loclist(ll_ref);
@@ -2684,7 +2694,7 @@ static int qf_jump_to_usable_window(int qf_fnum, int *opened_window)
 
   // If there is only one window and it is the quickfix window, create a
   // new one above the quickfix window.
-  if ((ONE_WINDOW && bt_quickfix(curbuf)) || !usable_win) {
+  if ((ONE_WINDOW && bt_quickfix(curbuf)) || !usable_win || newwin) {
     if (qf_open_new_file_win(ll_ref) != OK) {
       return FAIL;
     }
@@ -2823,11 +2833,12 @@ static void qf_jump_print_msg(qf_info_T *qi, int qf_index, qfline_T *qf_ptr,
 }
 
 /// Find a usable window for opening a file from the quickfix/location list. If
-/// a window is not found then open a new window.
+/// a window is not found then open a new window. If 'newwin' is true, then open
+/// a new window.
 /// Returns OK if successfully jumped or opened a window. Returns FAIL if not
 /// able to jump/open a window.  Returns NOTDONE if a file is not associated
 /// with the entry.
-static int qf_jump_open_window(qf_info_T *qi, qfline_T *qf_ptr,
+static int qf_jump_open_window(qf_info_T *qi, qfline_T *qf_ptr, bool newwin,
                                int *opened_window)
 {
   qf_list_T *qfl = qf_get_curlist(qi);
@@ -2837,7 +2848,7 @@ static int qf_jump_open_window(qf_info_T *qi, qfline_T *qf_ptr,
 
     // For ":helpgrep" find a help window or open one.
   if (qf_ptr->qf_type == 1 && (!bt_help(curwin->w_buffer) || cmdmod.tab != 0)) {
-    if (jump_to_help_window(qi, opened_window) == FAIL) {
+    if (jump_to_help_window(qi, newwin, opened_window) == FAIL) {
       return FAIL;
     }
   }
@@ -2861,7 +2872,8 @@ static int qf_jump_open_window(qf_info_T *qi, qfline_T *qf_ptr,
       return NOTDONE;
     }
 
-    if (qf_jump_to_usable_window(qf_ptr->qf_fnum, opened_window) == FAIL) {
+    if (qf_jump_to_usable_window(qf_ptr->qf_fnum, newwin, opened_window)
+        == FAIL) {
       return FAIL;
     }
   }
@@ -2924,14 +2936,22 @@ static int qf_jump_to_buffer(qf_info_T *qi, int qf_index, qfline_T *qf_ptr,
   return retval;
 }
 
-/// jump to a quickfix ltne
+/// Jump to a quickfix line.
-/// if dir == FORWARD go "errornr" valid entries forward
+/// If dir == FORWARD go "errornr" valid entries forward.
-/// if dir == BACKWARD go "errornr" valid entries backward
+/// If dir == BACKWARD go "errornr" valid entries backward.
-/// if dir == FORWARD_FILE go "errornr" valid entries files backward
+/// If dir == FORWARD_FILE go "errornr" valid entries files backward.
-/// if dir == BACKWARD_FILE go "errornr" valid entries files backward
+/// If dir == BACKWARD_FILE go "errornr" valid entries files backward.
 /// else if "errornr" is zero, redisplay the same line
-/// else go to entry "errornr"
+/// else go to entry "errornr".
 void qf_jump(qf_info_T *qi, int dir, int errornr, int forceit)
+{
+  qf_jump_newwin(qi, dir, errornr, forceit, false);
+}
+
+// As qf_info().
+// If 'newwin' is true, then open the file in a new window.
+static void qf_jump_newwin(qf_info_T *qi, int dir, int errornr, int forceit,
+                           bool newwin)
 {
   qf_list_T *qfl;
   qfline_T *qf_ptr;
@@ -2975,7 +2995,7 @@ void qf_jump(qf_info_T *qi, int dir, int errornr, int forceit)
     print_message = false;
   }
 
-  retval = qf_jump_open_window(qi, qf_ptr, &opened_window);
+  retval = qf_jump_open_window(qi, qf_ptr, newwin, &opened_window);
   if (retval == FAIL) {
     goto failed;
   }
@@ -3445,14 +3465,9 @@ void qf_view_result(bool split)
   }
 
   if (split) {
-    char cmd[32];
+    // Open the selected entry in a new window
-
+    qf_jump_newwin(qi, 0, (int)curwin->w_cursor.lnum, false, true);
-    snprintf(cmd, sizeof(cmd), "split +%" PRId64 "%s",
+    do_cmdline_cmd("clearjumps");
-             (int64_t)curwin->w_cursor.lnum,
-             IS_LL_WINDOW(curwin) ? "ll" : "cc");
-    if (do_cmdline_cmd(cmd) == OK) {
-      do_cmdline_cmd("clearjumps");
-    }
     return;
   }
 

src/nvim/testdir/test_quickfix.vim

@@ -3869,6 +3869,52 @@ func Test_curswant()
   cclose | helpclose
 endfunc
 
+" Test for opening a file from the quickfix window using CTRL-W <Enter>
+" doesn't leave an empty buffer around.
+func Test_splitview()
+  call s:create_test_file('Xtestfile1')
+  call s:create_test_file('Xtestfile2')
+  new | only
+  let last_bufnr = bufnr('Test_sv_1', 1)
+  let l = ['Xtestfile1:2:Line2', 'Xtestfile2:4:Line4']
+  cgetexpr l
+  copen
+  let numbufs = len(getbufinfo())
+  exe "normal \<C-W>\<CR>"
+  copen
+  exe "normal j\<C-W>\<CR>"
+  " Make sure new empty buffers are not created
+  call assert_equal(numbufs, len(getbufinfo()))
+  " Creating a new buffer should use the next available buffer number
+  call assert_equal(last_bufnr + 4, bufnr("Test_sv_2", 1))
+  bwipe Test_sv_1
+  bwipe Test_sv_2
+  new | only
+
+  " When split opening files from location list window, make sure that two
+  " windows doesn't refer to the same location list
+  lgetexpr l
+  let locid = getloclist(0, {'id' : 0}).id
+  lopen
+  exe "normal \<C-W>\<CR>"
+  call assert_notequal(locid, getloclist(0, {'id' : 0}).id)
+  call assert_equal(0, getloclist(0, {'winid' : 0}).winid)
+  new | only
+
+  " When split opening files from a helpgrep location list window, a new help
+  " window should be opend with a copy of the location list.
+  lhelpgrep window
+  let locid = getloclist(0, {'id' : 0}).id
+  lwindow
+  exe "normal j\<C-W>\<CR>"
+  call assert_notequal(locid, getloclist(0, {'id' : 0}).id)
+  call assert_equal(0, getloclist(0, {'winid' : 0}).winid)
+  new | only
+
+  call delete('Xtestfile1')
+  call delete('Xtestfile2')
+endfunc
+
 " Test for parsing entries using visual screen column
 func Test_viscol()
   enew