raise OSError if acl_to_text / acl_from_text returns NULL

Also did a small structural refactors there.

src/borg/platform/darwin.pyx

@@ -128,7 +128,7 @@ def acl_get(path, item, st, numeric_ids=False, fd=None):
             raise OSError(errno.errno, os.strerror(errno.errno), os.fsdecode(path))
         text = acl_to_text(acl, NULL)
         if text == NULL:
-            return
+            raise OSError(errno.errno, os.strerror(errno.errno), os.fsdecode(path))
         if numeric_ids:
             item['acl_extended'] = _remove_non_numeric_identifier(text)
         else:
@@ -143,14 +143,14 @@ def acl_set(path, item, numeric_ids=False, fd=None):
     acl_text = item.get('acl_extended')
     if acl_text is not None:
         try:
+            if isinstance(path, str):
+                path = os.fsencode(path)
             if numeric_ids:
                 acl = acl_from_text(acl_text)
             else:
                 acl = acl_from_text(<bytes>_remove_numeric_id_if_possible(acl_text))
             if acl == NULL:
-                return
-            if isinstance(path, str):
-                path = os.fsencode(path)
+                raise OSError(errno.errno, os.strerror(errno.errno), os.fsdecode(path))
             if fd is not None:
                 if acl_set_fd_np(fd, acl, ACL_TYPE_EXTENDED) == -1:
                     raise OSError(errno.errno, os.strerror(errno.errno), os.fsdecode(path))

src/borg/platform/freebsd.pyx

@@ -128,15 +128,15 @@ cdef _get_acl(p, type, item, attribute, flags, fd=None):
         acl = acl_get_fd_np(fd, type)
     else:
         acl = acl_get_link_np(p, type)
-    if acl:
-        text = acl_to_text_np(acl, NULL, flags)
-        if text:
-            item[attribute] = text
-            acl_free(text)
+    if acl == NULL:
+        raise OSError(errno.errno, os.strerror(errno.errno), os.fsdecode(p))
+    text = acl_to_text_np(acl, NULL, flags)
+    if text == NULL:
         acl_free(acl)
-    else:
         raise OSError(errno.errno, os.strerror(errno.errno), os.fsdecode(p))
-
+    item[attribute] = text
+    acl_free(text)
+    acl_free(acl)
 
 def acl_get(path, item, st, numeric_ids=False, fd=None):
     """Saves ACL Entries
@@ -166,16 +166,17 @@ cdef _set_acl(p, type, item, attribute, numeric_ids=False, fd=None):
         elif numeric_ids and type in(ACL_TYPE_ACCESS, ACL_TYPE_DEFAULT):
             text = posix_acl_use_stored_uid_gid(text)
         acl = acl_from_text(<bytes>text)
-        if acl:
-            try:
-                if fd is not None:
-                    if acl_set_fd_np(fd, acl, type) == -1:
-                        raise OSError(errno.errno, os.strerror(errno.errno), os.fsdecode(p))
-                else:
-                    if acl_set_link_np(p, type, acl) == -1:
-                        raise OSError(errno.errno, os.strerror(errno.errno), os.fsdecode(p))
-            finally:
-                acl_free(acl)
+        if acl == NULL:
+            raise OSError(errno.errno, os.strerror(errno.errno), os.fsdecode(p))
+        try:
+            if fd is not None:
+                if acl_set_fd_np(fd, acl, type) == -1:
+                    raise OSError(errno.errno, os.strerror(errno.errno), os.fsdecode(p))
+            else:
+                if acl_set_link_np(p, type, acl) == -1:
+                    raise OSError(errno.errno, os.strerror(errno.errno), os.fsdecode(p))
+        finally:
+            acl_free(acl)
 
 
 cdef _nfs4_use_stored_uid_gid(acl):

src/borg/platform/linux.pyx

@@ -260,12 +260,14 @@ def acl_get(path, item, st, numeric_ids=False, fd=None):
                 raise OSError(errno.errno, os.strerror(errno.errno), os.fsdecode(path))
         if access_acl:
             access_text = acl_to_text(access_acl, NULL)
-            if access_text:
-                item['acl_access'] = converter(access_text)
+            if access_text == NULL:
+                raise OSError(errno.errno, os.strerror(errno.errno), os.fsdecode(path))
+            item['acl_access'] = converter(access_text)
         if default_acl:
             default_text = acl_to_text(default_acl, NULL)
-            if default_text:
-                item['acl_default'] = converter(default_text)
+            if default_text == NULL:
+                raise OSError(errno.errno, os.strerror(errno.errno), os.fsdecode(path))
+            item['acl_default'] = converter(default_text)
     finally:
         acl_free(default_text)
         acl_free(default_acl)
@@ -291,23 +293,25 @@ def acl_set(path, item, numeric_ids=False, fd=None):
     if access_text:
         try:
             access_acl = acl_from_text(<bytes>converter(access_text))
-            if access_acl:
-                if fd is not None:
-                    if acl_set_fd(fd, access_acl) == -1:
-                        raise OSError(errno.errno, os.strerror(errno.errno), os.fsdecode(path))
-                else:
-                    if acl_set_file(path, ACL_TYPE_ACCESS, access_acl) == -1:
-                        raise OSError(errno.errno, os.strerror(errno.errno), os.fsdecode(path))
+            if access_acl == NULL:
+                raise OSError(errno.errno, os.strerror(errno.errno), os.fsdecode(path))
+            if fd is not None:
+                if acl_set_fd(fd, access_acl) == -1:
+                    raise OSError(errno.errno, os.strerror(errno.errno), os.fsdecode(path))
+            else:
+                if acl_set_file(path, ACL_TYPE_ACCESS, access_acl) == -1:
+                    raise OSError(errno.errno, os.strerror(errno.errno), os.fsdecode(path))
         finally:
             acl_free(access_acl)
     default_text = item.get('acl_default')
     if default_text:
         try:
             default_acl = acl_from_text(<bytes>converter(default_text))
-            if default_acl:
-                # only directories can get a default ACL. there is no fd-based api to set it.
-                if acl_set_file(path, ACL_TYPE_DEFAULT, default_acl) == -1:
-                    raise OSError(errno.errno, os.strerror(errno.errno), os.fsdecode(path))
+            if default_acl == NULL:
+                raise OSError(errno.errno, os.strerror(errno.errno), os.fsdecode(path))
+            # only directories can get a default ACL. there is no fd-based api to set it.
+            if acl_set_file(path, ACL_TYPE_DEFAULT, default_acl) == -1:
+                raise OSError(errno.errno, os.strerror(errno.errno), os.fsdecode(path))
         finally:
             acl_free(default_acl)