BUG/MINOR: tools: use my_unsetenv instead of unsetenv

Let's use our own implementation of unsetenv() instead of the one, which is
provided in libc. Implementation from libc may vary in dependency of UNIX
distro. Implemenation from libc.so.1 ported on Illumos (see the link below) has
caused an eternal loop in the clean_env(), where we invoke unsetenv().

(https://github.com/illumos/illumos-gate/blob/master/usr/src/lib/libc/port/gen/getenv.c#L411C1-L456C1)

This is reported at GitHUB #3018 and the reporter has proposed the patch, which
we really appreciate! But looking at his fix and to the implementations of
unsetenv() in FreeBSD libc and in Linux glibc 2.31, it seems, that the algorithm
of clean_env() will perform better with our my_unsetenv() implementation.

This should be backported in versions 3.1 and 3.2.

diff --git a/src/tools.c b/src/tools.c
index 731d8f93cf5de285a65f4fe22bcf122a79ade8a4..4507564bce86ac34a40706fdc8a02f3f18e51904 100644 (file)
--- a/src/tools.c
+++ b/src/tools.c
@@ -7147,7 +7147,7 @@ int backup_env(void)
  * doesn't contain "=" (the latter is mandatory format for strings kept in
  * **environ). This allows to terminate the process at the startup stage, if it
  * was launched in zero-warning mode and there are some problems with
- * environment.
+ * environment. It's not thread-safe as uses my_unsetenv, which is not thread-safe.
  */
 int clean_env(void)
 {
@@ -7172,9 +7172,8 @@ int clean_env(void)
                        return -1;
                }
 
-               if (unsetenv(name) != 0)
-                       ha_warning("unsetenv() fails for '%s': %s.\n",
-                                  name, strerror(errno));
+               my_unsetenv(name);
+
                free(name);
        }