Ensure handle is valid and pm_errno is reset when calling into API

We didn't do due diligence before and ensure prior pm_errno values
weren't influencing what happened in further ALPM calls. I observed one
case of early setup code setting pm_errno to PM_ERR_WRONG_ARGS and that
flag persisting the entire time we were calling library code.

Add a new CHECK_HANDLE() macro that does two things: 1) ensures the
handle variable passed to it is non-NULL and 2) clears any existing
pm_errno flag set on the handle. This macro can replace many places we
used the ASSERT(handle != NULL, ...) pattern before.

Several other other places only need a simple 'set to zero' of the
pm_errno field.

Signed-off-by: Dan McGee <dan@archlinux.org>

1 files changed, 2 insertions, 0 deletions

diff --git a/lib/libalpm/signing.c b/lib/libalpm/signing.c
index 8124e674..62c8925f 100644
--- a/lib/libalpm/signing.c
+++ b/lib/libalpm/signing.c
@@ -386,6 +386,7 @@ pgp_verify_t _alpm_db_get_sigverify_level(pmdb_t *db)
 int SYMEXPORT alpm_pkg_check_pgp_signature(pmpkg_t *pkg)
 {
 	ASSERT(pkg != NULL, return 0);
+	pkg->handle->pm_errno = 0;
 
 	return _alpm_gpgme_checksig(pkg->handle, alpm_pkg_get_filename(pkg),
 			pkg->base64_sig);
@@ -399,6 +400,7 @@ int SYMEXPORT alpm_pkg_check_pgp_signature(pmpkg_t *pkg)
 int SYMEXPORT alpm_db_check_pgp_signature(pmdb_t *db)
 {
 	ASSERT(db != NULL, return 0);
+	db->handle->pm_errno = 0;
 
 	return _alpm_gpgme_checksig(db->handle, _alpm_db_path(db), NULL);
 }