oci-image-tool commands ‘validate’ and ‘create’ failing for tar and zip images

[knieriem]

Due to a change in rev. 9027d58 validating an image in a tar (or zip) file is failing currently with the following message:

<tar-image>: find failed: unable to walk: end of walk

This is because in the context of the transition from using w.walk to w.find in findManifest (and, similar, findConfig) which has been done in 9027d58, the interaction between walk/findFunc and error handling, especially regarding errEOW, appears not to have been adjusted accordingly.

I have created a patch knieriem@06a4e96 that describes in more detail what is happening, and adjusts how image.findManifest and image.findConfig interact with image.walker.find so that validate and create commands work again for tar and zip files.

[zhouhao3]

@knieriem Can you push that patch to this community to solve this problem?