env: Allow returning errors from hdelete_r()
At present this function returns 1 on success and 0 on failure. But in
the latter case it provides no indication of what went wrong.
If an attempt is made to delete a non-existent variable, the caller may
want to ignore this error. This happens when setting a non-existent
variable to "", for example.
Update the function to return 0 on success and a useful error code on
failure. Add a function comment too.
Make sure that env_set() does not return an error if it is deleting a
variable that doesn't exist. We could update env_set() to return useful
error numbers also, but that is beyond the scope of this change.
Signed-off-by: Simon Glass <sjg@chromium.org>
wip
diff --git a/cmd/nvedit.c b/cmd/nvedit.c
index 7fce723..d0d2eca 100644
--- a/cmd/nvedit.c
+++ b/cmd/nvedit.c
@@ -266,7 +266,9 @@
/* Delete only ? */
if (argc < 3 || argv[2] == NULL) {
int rc = hdelete_r(name, &env_htab, env_flag);
- return !rc;
+
+ /* If the variable didn't exist, don't report an error */
+ return rc && rc != -ENOENT ? 1 : 0;
}
/*
@@ -895,7 +897,7 @@
while (--argc > 0) {
char *name = *++argv;
- if (!hdelete_r(name, &env_htab, env_flag))
+ if (hdelete_r(name, &env_htab, env_flag))
ret = 1;
}