ERANGE strikes again: RFH

[j6t]

I have to build with SNPRINTF_RETURNS_BOGUS. We know already that compat/snprintf overwrites errno with ERANGE in the case where a too small buffer is passed to the function.

I observe failures such as this one in t0410-partial-clone.sh:

++ git -C repo fsck
Checking object directories: 100% (256/256), done.
Checking objects: 100% (1/1), done.
fatal: failed to read object 3836707...snip...6591523: Result too large

The messages is from read_object_file_extended() in sha1-file.c.
It looks like we call into strbuf after a lower-level error return,
but before the error is checked. Does someone know where this
could happen?

The reason I'm asking is that today's tool chain is sufficiently broken for me
on Windows that I can't use the debugger. A hint where to start debugging
with fprintf would be helpful.

[gitgitgadget]

Welcome to GitGitGadget

Hi @j6t, and welcome to GitGitGadget, the GitHub App to send patch series to the Git mailing list from GitHub Pull Requests.

Please make sure that this Pull Request has a good description, as it will be used as cover letter.

Also, it is a good idea to review the commit messages one last time, as the Git project expects them in a quite specific form:

• the lines should not exceed 76 columns,
• the first line should be like a header and typically start with a prefix like "tests:" or "commit:", and
• the commit messages' body should be describing the "why?" of the change.
• Finally, the commit messages should end in a Signed-off-by: line matching the commits' author.

It is in general a good idea to await the automated test ("Checks") in this Pull Request before contributing the patches, e.g. to avoid trivial issues such as unportable code.

Contributing the patches

Before you can contribute the patches, your GitHub username needs to be added to the list of permitted users. Any already-permitted user can do that, by adding a comment to your PR of the form /allow. A good way to find other contributors is to locate recent pull requests where someone has been /allowed:

• Search: is:pr is:open "/allow"

Both the person who commented /allow and the PR author are able to /allow you.

An alternative is the channel #git-devel on the FreeNode IRC network:

<newcontributor> I've just created my first PR, could someone please /allow me? https://github.com/gitgitgadget/git/pull/12345
<veteran> newcontributor: it is done
<newcontributor> thanks!

Once on the list of permitted usernames, you can contribute the patches to the Git mailing list by adding a PR comment /submit.

After you submit, GitGitGadget will respond with another comment that contains the link to the cover letter mail in the Git mailing list archive. Please make sure to monitor the discussion in that thread and to address comments and suggestions.

If you want to see what email(s) would be sent for a submit request, add a PR comment /preview to have the email(s) sent to you. You must have a public GitHub email address for this.

If you do not want to subscribe to the Git mailing list just to be able to respond to a mail, you can download the mbox ("raw") file corresponding to the mail you want to reply to from the Git mailing list. If you use GMail, you can upload that raw mbox file via:

curl -g --user "<EMailAddress>:<Password>" --url "imaps://imap.gmail.com/INBOX" -T /path/to/raw.txt

Need help?

New contributors who want advice are encouraged to join git-mentoring@googlegroups.com, where volunteers who regularly contribute to Git are willing to answer newbie questions, give advice, or otherwise provide mentoring to interested contributors. You must join in order to post or view messages, but anyone can join.

You may also be able to find help in real time in the developer IRC channel, #git-devel on Freenode. Remember that IRC does not support offline messaging, so if you send someone a private message and log out, they cannot respond to you. The scrollback of #git-devel is archived, though.

[dscho]

/allow

[gitgitgadget]

User j6t is now allowed to use GitGitGadget.

WARNING: j6t has no public email address set on GitHub

[j6t]

I retract this patch for now. I have asked the mailing list to clarify whether restoration of errno like I do in this patch is actually necessary, or whether the caller that depends on that errno remains unmodified is bogus.