Re: Bug: git branch --unset-upstream command can nuke config when disk is full.

On Wed, Sep 13, 2017 at 04:49:45PM +0200, demerphq wrote:

On 13 September 2017 at 16:17, Jeff King [off-list ref] wrote:

quoted

You're welcome to read over the function to double-check, but I just
looked it over and couldn't find any unchecked writes.

I can look, but I doubt I would notice something you did not.

On the other hand the strace output does show that this is a case
where the writes failed, but we still renamed the empty config.lock
file into place:


write(3, "[core]\n\tsharedRepository = true\n"..., 288) = -1 ENOSPC
(No space left on device)
write(3, "        merge = refs/heads/yves/"..., 51) = -1 ENOSPC (No
space left on device)
munmap(0x7f48d9b8c000, 363)             = 0
close(3)                                = 0
rename("/usr/local/git_tree/main/.git/config.lock",
"/usr/local/git_tree/main/.git/config") = 0

Hmph. That is very disturbing. But with that information I should be
able to track down the culprit. Thanks for digging.

I freed up space and things worked, so I somehow doubt the filesystem
is at fault. When I then filled up the disk and retried the error was
repeatable.

Yeah, agreed. This really does look like a bug.

-Peff