vim-patch:8.2.4327: may end up with no current buffer

Problem:    May end up with no current buffer.
Solution:   When deleting the current buffer to not pick a quickfix buffer as
            the new current buffer.
https://github.com/vim/vim/commit/e3537aec2f8d6470010547af28dcbd83d41461b8

The test cannot be ported as-is because Nvim doesn't support "-Z"
command line argument. Just use only "--clean" instead.

2 files changed, 34 insertions, 4 deletions

diff --git a/src/nvim/buffer.c b/src/nvim/buffer.c
index 8d042525d3..4ca752e747 100644
--- a/src/nvim/buffer.c
+++ b/src/nvim/buffer.c
@@ -1284,8 +1284,10 @@ int do_buffer(int action, int start, int dir, int count, int forceit)
       while (jumpidx != curwin->w_jumplistidx) {
         buf = buflist_findnr(curwin->w_jumplist[jumpidx].fmark.fnum);
         if (buf != NULL) {
-          if (buf == curbuf || !buf->b_p_bl) {
-            buf = NULL;                 // skip current and unlisted bufs
+          // Skip current and unlisted bufs.  Also skip a quickfix
+          // buffer, it might be deleted soon.
+          if (buf == curbuf || !buf->b_p_bl || bt_quickfix(buf)) {
+            buf = NULL;
           } else if (buf->b_ml.ml_mfp == NULL) {
             // skip unloaded buf, but may keep it for later
             if (bp == NULL) {
@@ -1323,7 +1325,7 @@ int do_buffer(int action, int start, int dir, int count, int forceit)
           continue;
         }
         // in non-help buffer, try to skip help buffers, and vv
-        if (buf->b_help == curbuf->b_help && buf->b_p_bl) {
+        if (buf->b_help == curbuf->b_help && buf->b_p_bl && !bt_quickfix(buf)) {
           if (buf->b_ml.ml_mfp != NULL) {           // found loaded buffer
             break;
           }
@@ -1343,7 +1345,7 @@ int do_buffer(int action, int start, int dir, int count, int forceit)
     }
     if (buf == NULL) {          // No loaded buffer, find listed one
       FOR_ALL_BUFFERS(buf2) {
-        if (buf2->b_p_bl && buf2 != curbuf) {
+        if (buf2->b_p_bl && buf2 != curbuf && !bt_quickfix(buf2)) {
           buf = buf2;
           break;
         }
@@ -1355,6 +1357,9 @@ int do_buffer(int action, int start, int dir, int count, int forceit)
       } else {
         buf = curbuf->b_prev;
       }
+      if (bt_quickfix(buf)) {
+        buf = NULL;
+      }
     }
   }
 
diff --git a/src/nvim/testdir/test_quickfix.vim b/src/nvim/testdir/test_quickfix.vim
index a00231c5e9..5457223677 100644
--- a/src/nvim/testdir/test_quickfix.vim
+++ b/src/nvim/testdir/test_quickfix.vim
@@ -5505,5 +5505,30 @@ func Test_lopen_bwipe()
   delfunc R
 endfunc
 
+" Another sequence of commands that caused all buffers to be wiped out
+func Test_lopen_bwipe_all()
+  let lines =<< trim END
+    func R()
+      silent! tab lopen
+      e foo
+      silent! lfile
+    endfunc
+    cal R()
+    exe "norm \<C-W>\<C-V>0"
+    cal R()
+    bwipe
+
+    call writefile(['done'], 'Xresult')
+    qall!
+  END
+  call writefile(lines, 'Xscript')
+  if RunVim([], [], '--clean -n -S Xscript')
+    call assert_equal(['done'], readfile('Xresult'))
+  endif
+
+  call delete('Xscript')
+  call delete('Xresult')
+endfunc
+
 
 " vim: shiftwidth=2 sts=2 expandtab