Fix truncation of SHA in error message for git_odb_read - #3818

Push a commit to fix MSVC compile error. Should be good to go.

Welcome @meatcoder ! That's for looking into this;

Since git_oid_tostr takes the length of the buffer to write, I think that the function (as it exists in master) will truncate all ID strings, not just those of length GIT_OID_HEXSZ. I think that your patch will stop truncating the ID, but only when it is of length GIT_OID_HEXSZ. If someone were to provide (say) an id fragment that was 7 bytes long (when converted to hexadigits) then we would call git_oid_tostr(oidstr, 7, oid).

git_oid_tostr is documented to take the second argument as the buffer length, and is guaranteed to write a NULL terminator. This means that it would only write the first 6 characters, to make room for that NULL.

So I think that while this fixes the common case (when the ID is of length GIT_OID_HEXSZ) this does not fix all cases. Would you mind amending this to take care of all cases? Thanks!

Thanks for looking at this and the detailed explanation @ethomson. I've updated the pull request to to also fix the cases where shorter ID strings are passed to git_odb_read(). Let me know how it looks. Thanks again.

This looks great, thanks @meatcoder !

I squashed and manually merged this, thanks again!