uci: auto-load package in `ctx.foreach()` and `ctx.get_first()`

Functions that use `uci_lookup_ptr()` internally, such as `ctx.get()`,
`ctx.set()` or `ctx.delete()`, implicitly load the given configuration
name while the higher level functions `ctx.foreach()` or `ctx.get_first()`
do not.

This behaviour violates the principle of least surprise and might lead to
non-deterministic program behavior as the outcome of these functions
depends on prior uci operations performed on the cursor.

Fix this issue by invoking `uci_load()` internally in case the given
uci package name cannot be found in the cursor's package cache.

Signed-off-by: Jo-Philipp Wich <jo@mein.io>

1 files changed, 4 insertions, 6 deletions

diff --git a/lib/uci.c b/lib/uci.c
index 50cc050..b88dabd 100644
--- a/lib/uci.c
+++ b/lib/uci.c
@@ -346,8 +346,8 @@ uc_uci_get_first(uc_vm_t *vm, size_t nargs)
 		break;
 	}
 
-	if (!p)
-		err_return(UCI_ERR_NOTFOUND);
+	if (!p && uci_load(*c, ucv_string_get(conf), &p))
+		err_return((*c)->err);
 
 	uci_foreach_element(&p->sections, e) {
 		sc = uci_to_section(e);
@@ -917,8 +917,8 @@ uc_uci_foreach(uc_vm_t *vm, size_t nargs)
 		break;
 	}
 
-	if (!p)
-		err_return(UCI_ERR_NOTFOUND);
+	if (!p && uci_load(*c, ucv_string_get(conf), &p))
+		err_return((*c)->err);
 
 	uci_foreach_element_safe(&p->sections, tmp, e) {
 		sc = uci_to_section(e);
@@ -946,8 +946,6 @@ uc_uci_foreach(uc_vm_t *vm, size_t nargs)
 			break;
 	}
 
-	/* XXX: rethrow */
-
 	return ucv_boolean_new(ret);
 }