bug#70568: 30.0.50; build warnings on 'x86_64-pc-linux-gnu'

[David Ponce via "Bug reports for GNU Emacs, the Swiss army knife of text editors" <bug-gnu-emacs@gnu.org>]

Hello,

When I build Emacs configured for 'x86_64-pc-linux-gnu' on Fedora 39 with gcc 13.2.1
the below warnings are reported:


1) ./configure --with-x-toolkit=lucid --with-native-compilation=no

..
   CC       xterm.o
xterm.c: In function ‘x_alloc_nearest_color_1’:
xterm.c:9374:27: warning: potential null pointer dereference [-Wnull-dereference]
  9374 |   if (dpyinfo->visual_info.class == DirectColor)
       |       ~~~~~~~~~~~~~~~~~~~~^~~~~~
xterm.c:9374:27: warning: potential null pointer dereference [-Wnull-dereference]
...
   CC       eval.o
In file included from eval.c:25:
lisp.h: In function ‘internal_lisp_condition_case’:
lisp.h:1129:15: warning: variable ‘sym’ might be clobbered by ‘longjmp’ or ‘vfork’ [-Wclobbered]
  1129 |   Lisp_Object sym = XSYMBOL_WITH_POS (a)->sym;
       |               ^~~
eval.c:1413:43: warning: argument ‘var’ might be clobbered by ‘longjmp’ or ‘vfork’ [-Wclobbered]
  1413 | internal_lisp_condition_case (Lisp_Object var, Lisp_Object bodyform,
       |                               ~~~~~~~~~~~~^~~
...

2) ./configure --with-x-toolkit=gtk3 --with-cairo-xcb --with-native-compilation=no

...
   CC       eval.o
In file included from eval.c:25:
lisp.h: In function ‘internal_lisp_condition_case’:
lisp.h:1129:15: warning: variable ‘sym’ might be clobbered by ‘longjmp’ or ‘vfork’ [-Wclobbered]
  1129 |   Lisp_Object sym = XSYMBOL_WITH_POS (a)->sym;
       |               ^~~
eval.c:1413:43: warning: argument ‘var’ might be clobbered by ‘longjmp’ or ‘vfork’ [-Wclobbered]
  1413 | internal_lisp_condition_case (Lisp_Object var, Lisp_Object bodyform,
       |                               ~~~~~~~~~~~~^~~
...


In both cases (Lucid, gtk3) the reported warnings don't seem to affect run.
Thanks