patch 9.1.0170: Re-allow curwin == prevwin, but document it instead

Problem:  more places exist where curwin == prevwin, and it may even be
          expected in some cases.
Solution: revert v9.1.0001, but document that it's possible instead.
          (Sean Dewar)

I've had a change of heart for the following reasons:

- A quick 'n dirty [GitHub code
  search](https://github.com/search?q=%2F%28winnr%5C%28%5C%29%5Cs*%3D%3D%5Cs*winnr%5C%28%5B%27%22%5D%23%5B%27%22%5D%5C%29%7Cwinnr%5C%28%5B%27%22%5D%23%5B%27%22%5D%5C%29%5Cs*%3D%3D%5Cs*winnr%5C%28%5C%29%29%2F&type=code)
  reveals some cases where it's expected in the wild.

  Particularly, it made me aware `winnr() == winnr('#')` is possible when curwin
  is changed temporarily during the evaluation of a &statusline expression item
  (`%{...}`), and is used to show something different on the statusline
  belonging to the previous window; that behaviour wasn't changed in v9.1.0001,
  but it means curwin == prevwin makes sense in some cases.

- The definition and call sites of back_to_prevwin imply some expectation that
  prevwin == wp (== curwin) is possible, as it's used to skip entering the
  prevwin in that case.

- Prior to v9.1.0001, `:wincmd p` would not beep in the case that was patched in
  v9.1.0001, but now does. That resulted in #14047 being opened, as it affected
  the CtrlP plugin.

  I find it odd that `:wincmd p` had cases where it wouldn't beep despite doing
  nothing, but it may be preferable to keep things that way (or instead also
  beep if curwin == prevwin, if that's preferred).

- After more digging, I found cases in win_free_mem, enter_tabpage,
  aucmd_restbuf and qf_open_new_cwindow where curwin == prevwin is possible
  (many of them from autocommands). Others probably exist too, especially in
  places where curwin is changed temporarily.

fixes: #14047
closes: #14186

Signed-off-by: Sean Dewar <6256228+seandewar@users.noreply.github.com>
Signed-off-by: Christian Brabandt <cb@256bit.org>

diff --git a/runtime/doc/builtin.txt b/runtime/doc/builtin.txt
index fb957e54a95b038321841bc9cf046d92aa8a95a6..941c6a76ef1039ba6411ec6e390eae3c32511d0f 100644 (file)
--- a/runtime/doc/builtin.txt
+++ b/runtime/doc/builtin.txt
@@ -1,4 +1,4 @@
-*builtin.txt*  For Vim version 9.1.  Last change: 2024 Mar 07
+*builtin.txt*  For Vim version 9.1.  Last change: 2024 Mar 12
 
 
                  VIM REFERENCE MANUAL    by Bram Moolenaar
@@ -10947,7 +10947,9 @@ winnr([{arg}])  The result is a Number, which is the number of the current
                        #       the number of the last accessed window (where
                                |CTRL-W_p| goes to).  If there is no previous
                                window or it is in another tab page 0 is
-                               returned.
+                               returned.  May refer to the current window in
+                               some cases (e.g. when evaluating 'statusline'
+                               expressions).
                        {N}j    the number of the Nth window below the
                                current window (where |CTRL-W_j| goes to).
                        {N}k    the number of the Nth window above the current

diff --git a/src/globals.h b/src/globals.h
index dd3d2084fdf75090895b2e106b462f32a6c1f13d..f04f19dd2a61aa0508d418439100db9ccf3ab51c 100644 (file)
--- a/src/globals.h
+++ b/src/globals.h
@@ -976,7 +976,7 @@ EXTERN int  clip_unnamed_saved INIT(= 0);
  */
 EXTERN win_T   *firstwin;              // first window
 EXTERN win_T   *lastwin;               // last window
-EXTERN win_T   *prevwin INIT(= NULL);  // previous window
+EXTERN win_T   *prevwin INIT(= NULL);  // previous window (may equal curwin)
 #define ONE_WINDOW (firstwin == lastwin)
 #define W_NEXT(wp) ((wp)->w_next)
 

diff --git a/src/testdir/test_window_cmd.vim b/src/testdir/test_window_cmd.vim
index 917c43203c67fb5386d94039d952d96bf5bd24fb..fc4786d4acdc7e9d3dbd649c7c08f91b055b117a 100644 (file)
--- a/src/testdir/test_window_cmd.vim
+++ b/src/testdir/test_window_cmd.vim
@@ -131,64 +131,6 @@ func Test_window_quit()
   bw Xa Xb
 endfunc
 
-func Test_window_curwin_not_prevwin()
-  botright split
-  call assert_equal(2, winnr())
-  call assert_equal(1, winnr('#'))
-  quit
-  call assert_equal(1, winnr())
-  call assert_equal(0, winnr('#'))
-
-  botright split
-  botright split
-  call assert_equal(3, winnr())
-  call assert_equal(2, winnr('#'))
-  1quit
-  call assert_equal(2, winnr())
-  call assert_equal(1, winnr('#'))
-
-  botright split
-  call assert_equal(1, tabpagenr())
-  call assert_equal(3, winnr())
-  call assert_equal(2, winnr('#'))
-  wincmd T
-  call assert_equal(2, tabpagenr())
-  call assert_equal(1, winnr())
-  call assert_equal(0, winnr('#'))
-  tabfirst
-  call assert_equal(1, tabpagenr())
-  call assert_equal(2, winnr())
-  call assert_equal(0, winnr('#'))
-
-  tabonly
-  botright split
-  wincmd t
-  wincmd p
-  call assert_equal(3, winnr())
-  call assert_equal(1, winnr('#'))
-  quit
-  call assert_equal(2, winnr())
-  call assert_equal(1, winnr('#'))
-
-  botright split
-  wincmd t
-  wincmd p
-  call assert_equal(1, tabpagenr())
-  call assert_equal(3, winnr())
-  call assert_equal(1, winnr('#'))
-  wincmd T
-  call assert_equal(2, tabpagenr())
-  call assert_equal(1, winnr())
-  call assert_equal(0, winnr('#'))
-  tabfirst
-  call assert_equal(1, tabpagenr())
-  call assert_equal(2, winnr())
-  call assert_equal(1, winnr('#'))
-
-  tabonly
-  only
-endfunc
-
 func Test_window_horizontal_split()
   call assert_equal(1, winnr('$'))
   3wincmd s

diff --git a/src/version.c b/src/version.c
index fa4d6dc29c9950672885514171666a53d7012c95..73cdfa274e59839de279d2cd63f93f9e3555a971 100644 (file)
--- a/src/version.c
+++ b/src/version.c
@@ -704,6 +704,8 @@ static char *(features[]) =
 
 static int included_patches[] =
 {   /* Add new patch number below this line */
+/**/
+    170,
 /**/
     169,
 /**/

diff --git a/src/window.c b/src/window.c
index f893c12350ebe564338ad4ad758754d215a58378..00b35bbbbf40a7dcc2aaf0cb58c6425388147874 100644 (file)
--- a/src/window.c
+++ b/src/window.c
@@ -5526,15 +5526,11 @@ win_enter_ext(win_T *wp, int flags)
     // may have to copy the buffer options when 'cpo' contains 'S'
     if (wp->w_buffer != curbuf)
        buf_copy_options(wp->w_buffer, BCO_ENTER | BCO_NOHELP);
-
     if (curwin_invalid == 0)
     {
        prevwin = curwin;       // remember for CTRL-W p
        curwin->w_redr_status = TRUE;
     }
-    else if (wp == prevwin)
-       prevwin = NULL;         // don't want it to be the new curwin
-
     curwin = wp;
     curbuf = wp->w_buffer;
     check_cursor();