More disciplined use of 'errno'

Set errno to zero before calling any function where we may use its
errno, and check errno for zero before using it (as functions may
not set it even in error).

1 files changed, 2 insertions, 0 deletions

diff --git a/loslib.c b/loslib.c
index ad5a9276..ba80d72c 100644
--- a/loslib.c
+++ b/loslib.c
@@ -155,6 +155,7 @@ static int os_execute (lua_State *L) {
 
 static int os_remove (lua_State *L) {
   const char *filename = luaL_checkstring(L, 1);
+  errno = 0;
   return luaL_fileresult(L, remove(filename) == 0, filename);
 }
 
@@ -162,6 +163,7 @@ static int os_remove (lua_State *L) {
 static int os_rename (lua_State *L) {
   const char *fromname = luaL_checkstring(L, 1);
   const char *toname = luaL_checkstring(L, 2);
+  errno = 0;
   return luaL_fileresult(L, rename(fromname, toname) == 0, NULL);
 }