authorgravatar for squeek502@hotmail.comRyan Liptak <squeek502@hotmail.com> 2023-06-07 22:50:45-07:00
committergravatar for squeek502@hotmail.comRyan Liptak <squeek502@hotmail.com> 2023-06-08 02:16:15-07:00
logaf835111fa1397578392a4774454ac0d71eca77d
treeb089216012a03836c96facdb94c26a52815ed2e0
parent7555085e6304419c25bb870567eb265bb22d0337

Allow recovering from Walker.next errors without continually hitting the same error

Before this commit, if Walker.next errored with e.g. `error.AccessDenied` and the caller did something like `while (true) { walker.next() catch continue; }`, then the directory that errored with AccessDenied would be continually iterated in each `next` call and error every time with AccessDenied. After this commit, the directory that errored will be popped off the stack before the error is returned, meaning that in the subsequent `next` call, it won't be retried and the Walker will continue with whatever directories remain on its stack. For a real example, before this commit, walking `/proc/` on my system would infinitely loop due to repeated AccessDenied errors on the same directory. After this commit, I am able to walk `/proc/` on my system fully (skipping over any directories that are unable to be iterated).

1 files changed, 11 insertions(+), 1 deletions(-)

lib/std/fs.zig+11-1
......@@ -958,7 +958,17 @@ pub const IterableDir = struct {
958958 var top = &self.stack.items[self.stack.items.len - 1];
959959 var containing = top;
960960 var dirname_len = top.dirname_len;
961 if (try top.iter.next()) |base| {
961 if (top.iter.next() catch |err| {
962 // If we get an error, then we want the user to be able to continue
963 // walking if they want, which means that we need to pop the directory
964 // that errored from the stack. Otherwise, all future `next` calls would
965 // likely just fail with the same error.
966 var item = self.stack.pop();
967 if (self.stack.items.len != 0) {
968 item.iter.dir.close();
969 }
970 return err;
971 }) |base| {
962972 self.name_buffer.shrinkRetainingCapacity(dirname_len);
963973 if (self.name_buffer.items.len != 0) {
964974 try self.name_buffer.append(path.sep);