os_open: impl mch_open with libuv. ref #133

- use return value instead of open_req.result
- libuv uv_fs_open() returns `-errno` instead of always -1
- libuv always sets open_req.result to the return value, _except_ for OOM
  where it only sets the return value. So always use the return value.
- replace calls to mch_open macro.
- update call sites expecting -1 error

1 files changed, 2 insertions, 2 deletions

diff --git a/src/nvim/undo.c b/src/nvim/undo.c
index cb40878b43..b9f3309cef 100644
--- a/src/nvim/undo.c
+++ b/src/nvim/undo.c
@@ -1045,7 +1045,7 @@ void u_write_undo(char_u *name, int forceit, buf_T *buf, char_u *hash)
   if (os_file_exists(file_name)) {
     if (name == NULL || !forceit) {
       /* Check we can read it and it's an undo file. */
-      fd = mch_open((char *)file_name, O_RDONLY, 0);
+      fd = os_open((char *)file_name, O_RDONLY, 0);
       if (fd < 0) {
         if (name != NULL || p_verbose > 0) {
           if (name == NULL)
@@ -1089,7 +1089,7 @@ void u_write_undo(char_u *name, int forceit, buf_T *buf, char_u *hash)
     goto theend;
   }
 
-  fd = mch_open((char *)file_name,
+  fd = os_open((char *)file_name,
       O_CREAT|O_WRONLY|O_EXCL|O_NOFOLLOW, perm);
   if (fd < 0) {
     EMSG2(_(e_not_open), file_name);