vim-patch:7.4.1557 (#5117)

Problem:    Windows cannot be identified.
Solution:   Add a unique window number to each window and functions to use it.

https://github.com/vim/vim/commit/86edef664efccbfe685906c854b9cdd04e56f2d5

6 files changed, 200 insertions, 4 deletions

diff --git a/src/nvim/buffer_defs.h b/src/nvim/buffer_defs.h
index b515c4e1e4..46687f344c 100644
--- a/src/nvim/buffer_defs.h
+++ b/src/nvim/buffer_defs.h
@@ -937,8 +937,9 @@ struct matchitem {
  */
 struct window_S {
   uint64_t handle;
-  buf_T       *w_buffer;            /* buffer we are a window into (used
-                                       often, keep it the first item!) */
+  int w_id;                         ///< unique window ID
+  buf_T       *w_buffer;            ///< buffer we are a window into (used
+                                    ///< often, keep it the first item!)
 
   synblock_T  *w_s;                 /* for :ownsyntax */
 
diff --git a/src/nvim/eval.c b/src/nvim/eval.c
index a5333d74be..7839a7f645 100644
--- a/src/nvim/eval.c
+++ b/src/nvim/eval.c
@@ -6987,6 +6987,10 @@ static struct fst {
   { "virtcol",           1, 1, f_virtcol },
   { "visualmode",        0, 1, f_visualmode },
   { "wildmenumode",      0, 0, f_wildmenumode },
+  { "win_getid",         0, 2, f_win_getid },
+  { "win_gotoid",        1, 1, f_win_gotoid },
+  { "win_id2tabwin",     1, 1, f_win_id2tabwin },
+  { "win_id2win",        1, 1, f_win_id2win },
   { "winbufnr",          1, 1, f_winbufnr },
   { "wincol",            0, 0, f_wincol },
   { "winheight",         1, 1, f_winheight },
@@ -17150,6 +17154,32 @@ static void f_wildmenumode(typval_T *argvars, typval_T *rettv)
     rettv->vval.v_number = 1;
 }
 
+/// "win_getid()" function
+static void f_win_getid(typval_T *argvars, typval_T *rettv)
+{
+  rettv->vval.v_number = win_getid(argvars);
+}
+
+/// "win_gotoid()" function
+static void f_win_gotoid(typval_T *argvars, typval_T *rettv)
+{
+  rettv->vval.v_number = win_gotoid(argvars);
+}
+
+/// "win_id2tabwin()" function
+static void f_win_id2tabwin(typval_T *argvars, typval_T *rettv)
+{
+  if (rettv_list_alloc(rettv) != FAIL) {
+    win_id2tabwin(argvars, rettv->vval.v_list);
+  }
+}
+
+/// "win_id2win()" function
+static void f_win_id2win(typval_T *argvars, typval_T *rettv)
+{
+  rettv->vval.v_number = win_id2win(argvars);
+}
+
 /*
  * "winbufnr(nr)" function
  */
@@ -18437,7 +18467,7 @@ static void init_tv(typval_T *varp)
  * caller of incompatible types: it sets *denote to TRUE if "denote"
  * is not NULL or returns -1 otherwise.
  */
-static long get_tv_number(typval_T *varp)
+long get_tv_number(typval_T *varp)
 {
   int error = FALSE;
 
diff --git a/src/nvim/testdir/Makefile b/src/nvim/testdir/Makefile
index 9a0bba83fe..4979aae57a 100644
--- a/src/nvim/testdir/Makefile
+++ b/src/nvim/testdir/Makefile
@@ -39,6 +39,7 @@ NEW_TESTS = \
 	    test_timers.res \
 	    test_viml.res \
 	    test_visual.res \
+	    test_window_id.res \
 	    test_alot.res
 
 SCRIPTS_GUI := test16.out
diff --git a/src/nvim/testdir/test_window_id.vim b/src/nvim/testdir/test_window_id.vim
new file mode 100644
index 0000000000..b9e9f45c49
--- /dev/null
+++ b/src/nvim/testdir/test_window_id.vim
@@ -0,0 +1,71 @@
+" Test using the window ID.
+
+func Test_win_getid()
+  edit one
+  let id1 = win_getid()
+  split two
+  let id2 = win_getid()
+  split three
+  let id3 = win_getid()
+  tabnew
+  edit four
+  let id4 = win_getid()
+  split five
+  let id5 = win_getid()
+  tabnext
+
+  wincmd w
+  call assert_equal("two", expand("%"))
+  call assert_equal(id2, win_getid())
+  let nr2 = winnr()
+  wincmd w
+  call assert_equal("one", expand("%"))
+  call assert_equal(id1, win_getid())
+  let nr1 = winnr()
+  wincmd w
+  call assert_equal("three", expand("%"))
+  call assert_equal(id3, win_getid())
+  let nr3 = winnr()
+  tabnext
+  call assert_equal("five", expand("%"))
+  call assert_equal(id5, win_getid())
+  let nr5 = winnr()
+  wincmd w
+  call assert_equal("four", expand("%"))
+  call assert_equal(id4, win_getid())
+  let nr4 = winnr()
+  tabnext
+
+  exe nr1 . "wincmd w"
+  call assert_equal(id1, win_getid())
+  exe nr2 . "wincmd w"
+  call assert_equal(id2, win_getid())
+  exe nr3 . "wincmd w"
+  call assert_equal(id3, win_getid())
+  tabnext
+  exe nr4 . "wincmd w"
+  call assert_equal(id4, win_getid())
+  exe nr5 . "wincmd w"
+  call assert_equal(id5, win_getid())
+
+  call win_gotoid(id2)
+  call assert_equal("two", expand("%"))
+  call win_gotoid(id4)
+  call assert_equal("four", expand("%"))
+  call win_gotoid(id1)
+  call assert_equal("one", expand("%"))
+  call win_gotoid(id5)
+  call assert_equal("five", expand("%"))
+
+  call assert_equal(0, win_id2win(9999))
+  call assert_equal(nr5, win_id2win(id5))
+  call assert_equal(0, win_id2win(id1))
+  tabnext
+  call assert_equal(nr1, win_id2win(id1))
+
+  call assert_equal([0, 0], win_id2tabwin(9999))
+  call assert_equal([1, nr2], win_id2tabwin(id2))
+  call assert_equal([2, nr4], win_id2tabwin(id4))
+
+  only!
+endfunc
diff --git a/src/nvim/version.c b/src/nvim/version.c
index 6dcc8f622f..3b98b53068 100644
--- a/src/nvim/version.c
+++ b/src/nvim/version.c
@@ -720,7 +720,7 @@ static int included_patches[] = {
   // 1560 NA
   // 1559,
   // 1558,
-  // 1557,
+  1557,
   // 1556 NA
   // 1555 NA
   1554,
diff --git a/src/nvim/window.c b/src/nvim/window.c
index e267d493bf..350b54d595 100644
--- a/src/nvim/window.c
+++ b/src/nvim/window.c
@@ -3683,6 +3683,8 @@ win_T *buf_jump_open_tab(buf_T *buf)
   return NULL;
 }
 
+static int last_win_id = 0;
+
 /*
  * Allocate a window structure and link it in the window list when "hidden" is
  * FALSE.
@@ -3695,6 +3697,7 @@ static win_T *win_alloc(win_T *after, int hidden)
   win_T *new_wp = xcalloc(1, sizeof(win_T));
   handle_register_window(new_wp);
   win_alloc_lines(new_wp);
+  new_wp->w_id = ++last_win_id;
 
   /* init w: variables */
   new_wp->w_vars = dict_alloc();
@@ -5674,3 +5677,93 @@ static bool frame_check_width(frame_T *topfrp, int width)
   }
   return true;
 }
+
+int win_getid(typval_T *argvars)
+{
+  if (argvars[0].v_type == VAR_UNKNOWN) {
+    return curwin->w_id;
+  }
+  int winnr = get_tv_number(&argvars[0]);
+  win_T *wp;
+  if (winnr > 0) {
+    if (argvars[1].v_type == VAR_UNKNOWN) {
+      wp = firstwin;
+    } else {
+      tabpage_T *tp;
+      int tabnr = get_tv_number(&argvars[1]);
+      for (tp = first_tabpage; tp != NULL; tp = tp->tp_next) {
+        if (--tabnr == 0) {
+          break;
+        }
+      }
+      if (tp == NULL) {
+        return -1;
+      }
+      wp = tp->tp_firstwin;
+    }
+    for ( ; wp != NULL; wp = wp->w_next) {
+      if (--winnr == 0) {
+        return wp->w_id;
+      }
+    }
+  }
+  return 0;
+}
+
+int win_gotoid(typval_T *argvars)
+{
+  win_T *wp;
+  tabpage_T   *tp;
+  int id = get_tv_number(&argvars[0]);
+
+  for (tp = first_tabpage; tp != NULL; tp = tp->tp_next) {
+    for (wp = tp == curtab ? firstwin : tp->tp_firstwin;
+         wp != NULL; wp = wp->w_next) {
+      if (wp->w_id == id) {
+        goto_tabpage_win(tp, wp);
+        return 1;
+      }
+    }
+  }
+  return 0;
+}
+
+void win_id2tabwin(typval_T *argvars, list_T *list)
+{
+  win_T *wp;
+  tabpage_T   *tp;
+  int winnr = 1;
+  int tabnr = 1;
+  int id = get_tv_number(&argvars[0]);
+
+  for (tp = first_tabpage; tp != NULL; tp = tp->tp_next) {
+    for (wp = tp == curtab ? firstwin : tp->tp_firstwin;
+         wp != NULL; wp = wp->w_next) {
+      if (wp->w_id == id) {
+        list_append_number(list, tabnr);
+        list_append_number(list, winnr);
+        return;
+      }
+      winnr++;
+    }
+    tabnr++;
+    winnr = 1;
+  }
+  list_append_number(list, 0);
+  list_append_number(list, 0);
+}
+
+int win_id2win(typval_T *argvars)
+{
+  win_T   *wp;
+  int nr = 1;
+  int id = get_tv_number(&argvars[0]);
+
+  for (wp = firstwin; wp != NULL; wp = wp->w_next) {
+    if (wp->w_id == id) {
+      return nr;
+    }
+    nr++;
+  }
+  return 0;
+}