Re: Tab bar tabs landed on master

[Ergus]

Hi Juri:

I am trying the tabs in the master branch and with my config it works
fine in tui. But for some reason in GUI, when I create a new tab, emacs
freezes:

I have not reported this as a bug because it only happens with my
config, but I have no idea about what produces this (I don't have
anything too weird in my config).

==================================

In gdb the bt shows:

#0  0x000055addb2b837f in mark_object (arg=<optimized out>) at 
../../src/alloc.c:6583
#1  0x000055addb2b8f0e in mark_vectorlike (header=0x7f98b16ae700) at 
../../src/alloc.c:6157
#2  0x000055addb2b8373 in mark_object (arg=<optimized out>) at 
../../src/alloc.c:6581
#3  0x000055addb2b8f0e in mark_vectorlike (header=0x7f98b16ae660) at 
../../src/alloc.c:6157
#4  0x000055addb2b8373 in mark_object (arg=<optimized out>) at 
../../src/alloc.c:6581
#5  0x000055addb2b8f0e in mark_vectorlike (header=0x7f98b16ab3f8) at 
../../src/alloc.c:6157

(repeats this until)

#1968 0x000055addb2b8f0e in mark_vectorlike (header=0x7f98b167e4e0) at 
../../src/alloc.c:6157
#1969 0x000055addb2b8373 in mark_object (arg=<optimized out>) at 
../../src/alloc.c:6581
#1970 0x000055addb2b8f0e in mark_vectorlike (header=0x7f98b1bc0f28) at 
../../src/alloc.c:6157
#1971 0x000055addb2b8373 in mark_object (arg=<optimized out>) at 
../../src/alloc.c:6581
#1972 0x000055addb2b8169 in visit_vectorlike_root (type=GC_ROOT_BUFFER_LOCAL_DEFAULT, 
ptr=<optimized out>, visitor=...) at ../../src/alloc.c:5693
#1973 0x000055addb2b8169 in visit_buffer_root (type=GC_ROOT_BUFFER_LOCAL_DEFAULT, 
buffer=<optimized out>, visitor=...) at ../../src/alloc.c:5708
#1974 0x000055addb2b8169 in visit_static_gc_roots (visitor=...) at 
../../src/alloc.c:5720
#1975 0x000055addb2b9761 in garbage_collect () at ../../src/alloc.c:5941
#1976 0x000055addb2ba121 in maybe_garbage_collect () at ../../src/alloc.c:5853
#1977 0x000055addb2d6475 in maybe_gc () at ../../src/lisp.h:5061
#1978 0x000055addb2d6475 in Ffuncall (nargs=4, args=0x7ffc4de5fca0) at 
../../src/eval.c:2778
#1979 0x000055addb2d9164 in call3 (fn=<optimized out>, 
arg1=arg1@entry=0x55addd037973, arg2=<optimized out>, arg3=arg3@entry=0x0) at 
../../src/eval.c:2668

#1980 0x000055addb265012 in cmd_error_internal (data=data@entry=0x55addd037973, 
context=context@entry=0x7ffc4de5fd00 "") at ../../src/lisp.h:3935
#1981 0x000055addb26514d in cmd_error (data=0x55addd037973) at 
../../src/keyboard.c:953
#1982 0x000055addb2d5719 in internal_condition_case
    (bfun=bfun@entry=0x55addb26e140 <command_loop_1>, handlers=handlers@entry=0x90, 
hfun=hfun@entry=0x55addb265040 <cmd_error>) at ../../src/eval.c:1351
#1983 0x000055addb25fc24 in command_loop_2 (ignore=ignore@entry=0x0) at 
../../src/lisp.h:1032

#1984 0x000055addb2d5681 in internal_catch (tag=tag@entry=0xd4d0, 
func=func@entry=0x55addb25fc00 <command_loop_2>, arg=arg@entry=0x0) at 
../../src/eval.c:1116
#1985 0x000055addb25fbcb in command_loop () at ../../src/lisp.h:1032
#1986 0x000055addb264c56 in recursive_edit_1 () at ../../src/keyboard.c:714
#1987 0x000055addb264f82 in Frecursive_edit () at ../../src/keyboard.c:786
#1988 0x000055addb186910 in main (argc=1, argv=<optimized out>) at 
../../src/emacs.c:2055

===================================

See that this stack is too high and it seems to be triggered by the
garbage_collect call, so maybe I am just exposing some issue somewhere
else (maybe in the gc?).

I thought that this happened because I have this in the config:

```
(defun my/minibuffer-setup-hook ()
  (setq gc-cons-threshold most-positive-fixnum))

(defun my/minibuffer-exit-hook ()
  (setq gc-cons-threshold 800000)
  (garbage-collect))

(add-hook 'minibuffer-setup-hook #'my/minibuffer-setup-hook)
(add-hook 'minibuffer-exit-hook #'my/minibuffer-exit-hook)
```

But I commented it and it didn't change anything.

Do you have any idea about where to look to fix this?