refactor(wininfo): change wininfo from a linked list to an array

"wininfo" is going to be my next victim. The main problem with wininfo
is that it is "all or nothing", i e either all state about a buffer in a
window is considered valid or none of it is. This needs to be fixed to
address some long running grievances.

For now this is just a warmup: refactor it from a linked list to a
vector.

1 files changed, 18 insertions, 24 deletions

diff --git a/src/nvim/window.c b/src/nvim/window.c
index 938d9d7618..b1c483547c 100644
--- a/src/nvim/window.c
+++ b/src/nvim/window.c
@@ -5175,8 +5175,8 @@ win_T *win_alloc(win_T *after, bool hidden)
   return new_wp;
 }
 
-// Free one wininfo_T.
-void free_wininfo(wininfo_T *wip, buf_T *bp)
+// Free one WinInfo.
+void free_wininfo(WinInfo *wip, buf_T *bp)
 {
   if (wip->wi_optset) {
     clear_winopt(&wip->wi_opt);
@@ -5241,30 +5241,24 @@ void win_free(win_T *wp, tabpage_T *tp)
   // Remove the window from the b_wininfo lists, it may happen that the
   // freed memory is re-used for another window.
   FOR_ALL_BUFFERS(buf) {
-    for (wininfo_T *wip = buf->b_wininfo; wip != NULL; wip = wip->wi_next) {
+    WinInfo *wip_wp = NULL;
+    size_t pos_null = kv_size(buf->b_wininfo);
+    for (size_t i = 0; i < kv_size(buf->b_wininfo); i++) {
+      WinInfo *wip = kv_A(buf->b_wininfo, i);
       if (wip->wi_win == wp) {
-        wininfo_T *wip2;
-
-        // If there already is an entry with "wi_win" set to NULL it
-        // must be removed, it would never be used.
-        // Skip "wip" itself, otherwise Coverity complains.
-        for (wip2 = buf->b_wininfo; wip2 != NULL; wip2 = wip2->wi_next) {
-          // `wip2 != wip` to satisfy Coverity. #14884
-          if (wip2 != wip && wip2->wi_win == NULL) {
-            if (wip2->wi_next != NULL) {
-              wip2->wi_next->wi_prev = wip2->wi_prev;
-            }
-            if (wip2->wi_prev == NULL) {
-              buf->b_wininfo = wip2->wi_next;
-            } else {
-              wip2->wi_prev->wi_next = wip2->wi_next;
-            }
-            free_wininfo(wip2, buf);
-            break;
-          }
-        }
+        wip_wp = wip;
+      } else if (wip->wi_win == NULL) {
+        pos_null = i;
+      }
+    }
 
-        wip->wi_win = NULL;
+    if (wip_wp) {
+      wip_wp->wi_win = NULL;
+      // If there already is an entry with "wi_win" set to NULL it
+      // must be removed, it would never be used.
+      if (pos_null < kv_size(buf->b_wininfo)) {
+        free_wininfo(kv_A(buf->b_wininfo, pos_null), buf);
+        kv_shift(buf->b_wininfo, pos_null, 1);
       }
     }
   }