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From: Sam James <sam@gentoo.org>
Date: Fri, 4 Nov 2022 04:58:38 +0000
Subject: [PATCH] Fix -Wimplicit-function-declaration

Add <stdlib.h> includes for exit(). Clang 16 makes -Wimplicit-function-declaration an error by default.

Signed-off-by: Sam James <sam@gentoo.org>
--- a/configure.ac
+++ b/configure.ac
@@ -45,7 +45,8 @@ if test "x$ac_cv_func_getcwd" = xyes; then
 # We only need to run this if we have getcwd.
 AC_CACHE_CHECK([whether getcwd uses fork or vfork],
                [kb_cv_func_getcwd_forks],
-               [AC_RUN_IFELSE([AC_LANG_PROGRAM([[int fork() { exit(1); }
+               [AC_RUN_IFELSE([AC_LANG_PROGRAM([[#include <stdlib.h>
+                                                 int fork() { exit(1); }
                                                  int vfork() { exit(1); }
                                                  extern char *getcwd();
                                                  char path[100];]],
--- a/configure
+++ b/configure
@@ -13920,6 +13920,7 @@ else
 else
   cat confdefs.h - <<_ACEOF >conftest.$ac_ext
 /* end confdefs.h.  */
+#include <stdlib.h>
 int fork() { exit(1); }
                                                  int vfork() { exit(1); }
                                                  extern char *getcwd();