libbb: add bb_unsetenv (taken from hush).
udhcpc: stop filtering environment passed to the script.
crond: fix uncovered potential bug (failing unsetenv)
mdev: fix uncovered potential bug (failing unsetenv)
tcp, udpsvd: fix uncovered potential bug (failing unsetenv)
function old new delta
safe_setenv - 58 +58
bb_unsetenv - 55 +55
builtin_unset 139 138 -1
tcpudpsvd_main 1843 1830 -13
free_strings_and_unsetenv 87 53 -34
udhcp_run_script 1186 1133 -53
safe_setenv4 62 - -62
------------------------------------------------------------------------------
(add/remove: 2/1 grow/shrink: 0/4 up/down: 113/-163) Total: -50 bytes
diff --git a/include/libbb.h b/include/libbb.h
index e0541a7..e1a6d12 100644
--- a/include/libbb.h
+++ b/include/libbb.h
@@ -377,6 +377,7 @@
void xchdir(const char *path) FAST_FUNC;
void xchroot(const char *path) FAST_FUNC;
void xsetenv(const char *key, const char *value) FAST_FUNC;
+void bb_unsetenv(const char *key) FAST_FUNC;
void xunlink(const char *pathname) FAST_FUNC;
void xstat(const char *pathname, struct stat *buf) FAST_FUNC;
int xopen(const char *pathname, int flags) FAST_FUNC FAST_FUNC;