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, 1 insertions, 0 deletions

diff --git a/lib/libalpm/be_sync.c b/lib/libalpm/be_sync.c
index ccc8fdbe..bb109284 100644
--- a/lib/libalpm/be_sync.c
+++ b/lib/libalpm/be_sync.c
@@ -116,6 +116,7 @@ int SYMEXPORT alpm_db_update(int force, pmdb_t *db)
 	/* Sanity checks */
 	ASSERT(db != NULL, return -1);
 	handle = db->handle;
+	handle->pm_errno = 0;
 	ASSERT(db != handle->db_local, RET_ERR(handle, PM_ERR_WRONG_ARGS, -1));
 	ASSERT(db->servers != NULL, RET_ERR(handle, PM_ERR_SERVER_NONE, -1));