diff --git a/src/alloc.h b/src/alloc.h
index 9260018..35c00b6 100644
--- a/src/alloc.h
+++ b/src/alloc.h
@@ -40,5 +40,6 @@
     aid_sign_getplaced_list,
     aid_insert_sign,
     aid_sign_getinfo,
+    aid_buflistnew_bvars,
     aid_last
 } alloc_id_T;
diff --git a/src/buffer.c b/src/buffer.c
index 93da5dc..c8e63c3 100644
--- a/src/buffer.c
+++ b/src/buffer.c
@@ -2093,7 +2093,7 @@
 	}
 #ifdef FEAT_EVAL
 	// init b: variables
-	buf->b_vars = dict_alloc();
+	buf->b_vars = dict_alloc_id(aid_buflistnew_bvars);
 	if (buf->b_vars == NULL)
 	{
 	    vim_free(ffname);
diff --git a/src/popupwin.c b/src/popupwin.c
index 883372c..c3251ea 100644
--- a/src/popupwin.c
+++ b/src/popupwin.c
@@ -1997,7 +1997,10 @@
 	new_buffer = TRUE;
 	buf = buflist_new(NULL, NULL, (linenr_T)0, BLN_NEW|BLN_DUMMY|BLN_REUSE);
 	if (buf == NULL)
+	{
+	    win_free_popup(wp);
 	    return NULL;
+	}
 	ml_open(buf);
 
 	win_init_popup_win(wp, buf);
diff --git a/src/testdir/test_buffer.vim b/src/testdir/test_buffer.vim
index 0d87138..fd96c61 100644
--- a/src/testdir/test_buffer.vim
+++ b/src/testdir/test_buffer.vim
@@ -430,4 +430,74 @@
   set maxmem& maxmemtot&
 endfunc
 
+" Test for a allocation failure when adding a new buffer
+func Test_buflist_alloc_failure()
+  %bw!
+
+  edit Xfile1
+  call test_alloc_fail(GetAllocId('buflistnew_bvars'), 0, 0)
+  call assert_fails('edit Xfile2', 'E342:')
+
+  " test for bufadd()
+  call test_alloc_fail(GetAllocId('buflistnew_bvars'), 0, 0)
+  call assert_fails('call bufadd("Xbuffer")', 'E342:')
+
+  " test for setting the arglist
+  edit Xfile2
+  call test_alloc_fail(GetAllocId('buflistnew_bvars'), 0, 0)
+  call assert_fails('next Xfile3', 'E342:')
+
+  " test for setting the alternate buffer name when writing a file
+  call test_alloc_fail(GetAllocId('buflistnew_bvars'), 0, 0)
+  call assert_fails('write Xother', 'E342:')
+  call delete('Xother')
+
+  " test for creating a buffer using bufnr()
+  call test_alloc_fail(GetAllocId('buflistnew_bvars'), 0, 0)
+  call assert_fails("call bufnr('Xnewbuf', v:true)", 'E342:')
+
+  " test for renaming buffer using :file
+  call test_alloc_fail(GetAllocId('buflistnew_bvars'), 0, 0)
+  call assert_fails('file Xnewfile', 'E342:')
+
+  " test for creating a buffer for a popup window
+  call test_alloc_fail(GetAllocId('buflistnew_bvars'), 0, 0)
+  call assert_fails('call popup_create("mypop", {})', 'E342:')
+
+  if has('terminal')
+    " test for creating a buffer for a terminal window
+    call test_alloc_fail(GetAllocId('buflistnew_bvars'), 0, 0)
+    call assert_fails('call term_start(&shell)', 'E342:')
+    %bw!
+  endif
+
+  " test for loading a new buffer after wiping out all the buffers
+  edit Xfile4
+  call test_alloc_fail(GetAllocId('buflistnew_bvars'), 0, 0)
+  call assert_fails('%bw!', 'E342:')
+
+  " test for :checktime loading the buffer
+  call writefile(['one'], 'Xfile5')
+  if has('unix')
+    edit Xfile5
+    " sleep for some time to make sure the timestamp is different
+    sleep 200m
+    call writefile(['two'], 'Xfile5')
+    set autoread
+    call test_alloc_fail(GetAllocId('buflistnew_bvars'), 0, 0)
+    call assert_fails('checktime', 'E342:')
+    set autoread&
+    bw!
+  endif
+
+  " test for :vimgrep loading a dummy buffer
+  call test_alloc_fail(GetAllocId('buflistnew_bvars'), 0, 0)
+  call assert_fails('vimgrep two Xfile5', 'E342:')
+  call delete('Xfile5')
+
+  " test for quickfix command loading a buffer
+  call test_alloc_fail(GetAllocId('buflistnew_bvars'), 0, 0)
+  call assert_fails('cexpr "Xfile6:10:Line10"', 'E342:')
+endfunc
+
 " vim: shiftwidth=2 sts=2 expandtab
diff --git a/src/testdir/test_swap.vim b/src/testdir/test_swap.vim
index 143a9af..a464940 100644
--- a/src/testdir/test_swap.vim
+++ b/src/testdir/test_swap.vim
@@ -233,7 +233,6 @@
     autocmd SwapExists * let v:swapchoice = 'r'
   augroup END
 
-
   call mkdir('Xswap')
   let $Xswap = 'foo'  " Check for issue #4369.
   set dir=Xswap//
diff --git a/src/version.c b/src/version.c
index 6742703..311b878 100644
--- a/src/version.c
+++ b/src/version.c
@@ -751,6 +751,8 @@
 static int included_patches[] =
 {   /* Add new patch number below this line */
 /**/
+    4668,
+/**/
     4667,
 /**/
     4666,
diff --git a/src/window.c b/src/window.c
index 66dd099..78ce4d2 100644
--- a/src/window.c
+++ b/src/window.c
@@ -5256,10 +5256,13 @@
     void
 win_free_popup(win_T *win)
 {
-    if (bt_popup(win->w_buffer))
-	win_close_buffer(win, DOBUF_WIPE_REUSE, FALSE);
-    else
-	close_buffer(win, win->w_buffer, 0, FALSE, FALSE);
+    if (win->w_buffer != NULL)
+    {
+	if (bt_popup(win->w_buffer))
+	    win_close_buffer(win, DOBUF_WIPE_REUSE, FALSE);
+	else
+	    close_buffer(win, win->w_buffer, 0, FALSE, FALSE);
+    }
 # if defined(FEAT_TIMERS)
     if (win->w_popup_timer != NULL)
 	stop_timer(win->w_popup_timer);