[PATCH] env: remove vars that are not in default env

[Ravi Minnikanti]

current env_set_default_vars() doesn't delete
var that are not in the imported env. hashtable
removes vars that are not in the imported
env but present in the current env only if H_NOCLEAR
flag is not set.

This change is to avoid passing H_NOCLEAR flag if
specific vars are passed to env_set_default_vars()

Test:

Without this change:
Marvell>> env default boot_mode
Marvell>>

With the change:
Marvell>> env default boot_mode
WARNING: 'boot_mode' not in imported env, deleting it!

Signed-off-by: rminnikanti <rminnika...@marvell.com>
---
 env/common.c | 10 +++++++++-
 1 file changed, 9 insertions(+), 1 deletion(-)

diff --git a/env/common.c b/env/common.c
index 8d47d72605..2f783e3a69 100644
--- a/env/common.c
+++ b/env/common.c
@@ -401,7 +401,15 @@ int env_set_default_vars(int nvars, char * const vars[], 
int flags)
         * Special use-case: import from default environment
         * (and use \0 as a separator)
         */
-       flags |= H_NOCLEAR | H_DEFAULT;
+
+       /* 
+        * When vars are passed remove variables that are not in
+        * the default environment.
+        */
+       if (!nvars)
+               flags |= H_NOCLEAR;
+
+       flags |= H_DEFAULT;
        return himport_r(&env_htab, default_environment,
                                sizeof(default_environment), '\0',
                                flags, 0, nvars, vars);
-- 
2.25.1

Thanks,
Ravi