patch 9.1.1393: missing test for switching buffers and reusing curbuf

seandewar · chrisbra · commit 31be82e66d41 · 2025-05-15T19:59:37.000+02:00
Problem:  The check in buf_freeall that restores curwin subtly prevents
          leaving an unloaded buffer in a window when reusing curbuf, if
          autocommands switch to a different buffer.
Solution: Add a test case that covers this. Also ensure splitting isn't
          possible, as that could do the same (Sean Dewar)

closes: #17325

Signed-off-by: Sean Dewar &lt;6256228+seandewar@users.noreply.github.com&gt;
Signed-off-by: Christian Brabandt &lt;cb@256bit.org&gt;
diff --git a/src/buffer.c b/src/buffer.c
@@ -909,7 +909,7 @@ buf_freeall(buf_T *buf, int flags)
     // If the buffer was in curwin and the window has changed, go back to that
     // window, if it still exists.  This avoids that ":edit x" triggering a
     // "tabnext" BufUnload autocmd leaves a window behind without a buffer.
-    if (is_curwin && curwin != the_curwin &&  win_valid_any_tab(the_curwin))
+    if (is_curwin && curwin != the_curwin && win_valid_any_tab(the_curwin))
     {
 	block_autocmds();
 	goto_tabpage_win(the_curtab, the_curwin);
diff --git a/src/testdir/test_autocmd.vim b/src/testdir/test_autocmd.vim
@@ -5415,4 +5415,31 @@ func Test_reuse_curbuf_leak()
   %bw!
 endfunc
 
+func Test_reuse_curbuf_switch()
+  edit asdf
+  let s:asdf_win = win_getid()
+  new
+  let other_buf = bufnr()
+  let other_win = win_getid()
+  augroup testing
+    autocmd!
+    autocmd BufUnload * ++once let s:triggered = 1
+          \| call assert_fails('split', 'E1159:')
+          \| call win_gotoid(s:asdf_win)
+  augroup END
+
+  " Check BufUnload changing curbuf does not cause buflist_new to create a new
+  " buffer while leaving "other_buf" unloaded in a window.
+  enew
+  call assert_equal(1, s:triggered)
+  call assert_equal(other_buf, bufnr())
+  call assert_equal(other_win, win_getid())
+  call assert_equal(1, win_findbuf(other_buf)->len())
+  call assert_equal(1, bufloaded(other_buf))
+
+  unlet! s:asdf_win s:triggered
+  call CleanUpTestAuGroup()
+  %bw!
+endfunc
+
 " vim: shiftwidth=2 sts=2 expandtab
diff --git a/src/version.c b/src/version.c
@@ -709,6 +709,8 @@ static char *(features[]) =
 
 static int included_patches[] =
 {   /* Add new patch number below this line */
+/**/
+    1393,
 /**/
     1392,
 /**/

Original file line number	Diff line number	Diff line change
`@@ -909,7 +909,7 @@ buf_freeall(buf_T *buf, int flags)`
`909`	`909`	`// If the buffer was in curwin and the window has changed, go back to that`
`910`	`910`	`// window, if it still exists. This avoids that ":edit x" triggering a`
`911`	`911`	`// "tabnext" BufUnload autocmd leaves a window behind without a buffer.`
`912`		`- if (is_curwin && curwin != the_curwin && win_valid_any_tab(the_curwin))`
	`912`	`+ if (is_curwin && curwin != the_curwin && win_valid_any_tab(the_curwin))`
`913`	`913`	`{`
`914`	`914`	`block_autocmds();`
`915`	`915`	`goto_tabpage_win(the_curtab, the_curwin);`