patch 9.0.2168: Moving tabpages on :drop may cause an endless loop

Problem:  Moving tabpages on :drop may cause an endless loop
Solution: Disallow moving tabpages on :drop when cleaning up the arglist
          first

Moving tabpages during drop command may cause an endless loop

When executing a :tab drop command, Vim will close all windows not in
the argument list. This triggers various autocommands. If a user has
created an 'au Tabenter * :tabmove -' autocommand, this can cause Vim to
end up in an endless loop, when trying to iterate over all tabs (which
would trigger the tabmove autocommand, which will change the tpnext
pointer, etc).

So instead of blocking all autocommands before we actually try to edit
the given file, lets simply disallow to move tabpages around. Otherwise,
we may change the expected number of events triggered during a :drop
command, which users may rely on (there is actually a test, that expects
various TabLeave/TabEnter autocommands) and would therefore be a
backwards incompatible change.

Don't make this an error, as this could trigger several times during the
drop command, but silently ignore the :tabmove command in this case (and
it should in fact finally trigger successfully when loading the given
file in a new tab). So let's just be quiet here instead.

fixes:  #13676
closes: #13686

Signed-off-by: Christian Brabandt <cb@256bit.org>

diff --git a/src/arglist.c b/src/arglist.c
index a63f6c72f8bc0a77e152eaea43b7751ef3211902..d28b31da438c5589907cb2e2f227b374c92dc58d 100644 (file)
--- a/src/arglist.c
+++ b/src/arglist.c
@@ -983,6 +983,9 @@ arg_all_close_unused_windows(arg_all_state_T *aall)
 
     if (aall->had_tab > 0)
        goto_tabpage_tp(first_tabpage, TRUE, TRUE);
+
+    // moving tabpages around in an autocommand may cause an endless loop
+    tabpage_move_disallowed++;
     for (;;)
     {
        tpnext = curtab->tp_next;
@@ -1093,6 +1096,7 @@ arg_all_close_unused_windows(arg_all_state_T *aall)
 
        goto_tabpage_tp(tpnext, TRUE, TRUE);
     }
+    tabpage_move_disallowed--;
 }
 
 /*

diff --git a/src/globals.h b/src/globals.h
index d54e3118371e22c511a26e89860877d3e0ee20b8..c03fe97db918cb224088411ec70b4aad662ea041 100644 (file)
--- a/src/globals.h
+++ b/src/globals.h
@@ -792,8 +792,9 @@ EXTERN int  is_mac_terminal INIT(= FALSE);  // recognized Terminal.app
 #endif
 
 EXTERN int     autocmd_busy INIT(= FALSE);     // Is apply_autocmds() busy?
-EXTERN int     autocmd_no_enter INIT(= FALSE); // *Enter autocmds disabled
-EXTERN int     autocmd_no_leave INIT(= FALSE); // *Leave autocmds disabled
+EXTERN int     autocmd_no_enter INIT(= FALSE); // Buf/WinEnter autocmds disabled
+EXTERN int     autocmd_no_leave INIT(= FALSE); // Buf/WinLeave autocmds disabled
+EXTERN int     tabpage_move_disallowed INIT(= FALSE);  // moving tabpages around disallowed
 
 EXTERN int     modified_was_set;               // did ":set modified"
 EXTERN int     did_filetype INIT(= FALSE);     // FileType event found

diff --git a/src/testdir/test_tabpage.vim b/src/testdir/test_tabpage.vim
index eed26f72218143fc4106964674d4455389511532..906fefcab63cb9654abfcb2602d2142fa45ac424 100644 (file)
--- a/src/testdir/test_tabpage.vim
+++ b/src/testdir/test_tabpage.vim
@@ -903,4 +903,23 @@ func Test_tabpage_last_line()
   bwipe!
 endfunc
 
+" this was causing an endless loop
+func Test_tabpage_drop_tabmove()
+  augroup TestTabpageTabmove
+    au!
+    autocmd! TabEnter * :if tabpagenr() > 1 | tabmove - | endif
+  augroup end
+  $tab drop XTab_99.log
+  $tab drop XTab_98.log
+  $tab drop XTab_97.log
+
+  autocmd! TestTabpageTabmove
+  augroup! TestTabpageTabmove
+
+  " clean up
+  bwipe!
+  bwipe!
+  bwipe!
+endfunc
+
 " vim: shiftwidth=2 sts=2 expandtab

diff --git a/src/version.c b/src/version.c
index a81665af11b84ee585b8b4ca5f24b805667fa82d..03f44e46261fd1f10dfa5d2b1ff34cf6afc7b5f4 100644 (file)
--- a/src/version.c
+++ b/src/version.c
@@ -704,6 +704,8 @@ static char *(features[]) =
 
 static int included_patches[] =
 {   /* Add new patch number below this line */
+/**/
+    2168,
 /**/
     2167,
 /**/

diff --git a/src/window.c b/src/window.c
index be010dc7fdccfe7dd981f08e0c9f8d9bf2e90569..9f8065712447498679e47e13d97406a5b0ad1332 100644 (file)
--- a/src/window.c
+++ b/src/window.c
@@ -4970,6 +4970,9 @@ tabpage_move(int nr)
     if (first_tabpage->tp_next == NULL)
        return;
 
+    if (tabpage_move_disallowed)
+       return;
+
     for (tp = first_tabpage; tp->tp_next != NULL && n < nr; tp = tp->tp_next)
        ++n;