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 a63f6c7..d28b31d 100644
--- a/src/arglist.c
+++ b/src/arglist.c
@@ -983,6 +983,9 @@
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 @@
goto_tabpage_tp(tpnext, TRUE, TRUE);
}
+ tabpage_move_disallowed--;
}
/*
diff --git a/src/globals.h b/src/globals.h
index d54e311..c03fe97 100644
--- a/src/globals.h
+++ b/src/globals.h
@@ -792,8 +792,9 @@
#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 eed26f7..906fefc 100644
--- a/src/testdir/test_tabpage.vim
+++ b/src/testdir/test_tabpage.vim
@@ -903,4 +903,23 @@
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 a81665a..03f44e4 100644
--- a/src/version.c
+++ b/src/version.c
@@ -705,6 +705,8 @@
static int included_patches[] =
{ /* Add new patch number below this line */
/**/
+ 2168,
+/**/
2167,
/**/
2166,
diff --git a/src/window.c b/src/window.c
index be010dc..9f80657 100644
--- a/src/window.c
+++ b/src/window.c
@@ -4970,6 +4970,9 @@
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;