Hello,

I've spotted a segfault during `got fetch -d'

In got.c:2040

   2039                 TAILQ_FOREACH(pe, their_refs, entry) {
   2040                         if (strcmp(local_refname, pe->path) == 0)
   2041                                 break;
   2042                 }

local_refname is NULL and strcmp crashes.  I couldn't get a
corefile thought

--8<---------------cut here---------------start------------->8---
% egdb got
(gdb) r fetch -d
Starting program: /home/op/bin/got fetch -d
[New process 79176]
Connecting to "origin" git@omarpolo.com
Already up-to-date

Thread 1 received signal SIGSEGV, Segmentation fault.
strcmp () at /usr/src/lib/libc/arch/amd64/string/strcmp.S:45
45              movq    8(%rdi),%rax
(gdb) bt
#0  strcmp () at /usr/src/lib/libc/arch/amd64/string/strcmp.S:45
#1  0x000006cbf275413a in delete_missing_refs (their_refs=0x7f7ffffecf00,
    their_symrefs=0x7f7ffffecef0, remote=0x6cdfe936250, verbosity=0,
    repo=0x6cdfe917070) at got.c:2040
#2  0x000006cbf274475c in cmd_fetch (argc=0, argv=0x7f7ffffed0a0) at got.c:2538
#3  0x000006cbf274105f in main (argc=2, argv=0x7f7ffffed090) at got.c:252
(gdb) f 1
#1  0x000006cbf275413a in delete_missing_refs (their_refs=0x7f7ffffecf00,
    their_symrefs=0x7f7ffffecef0, remote=0x6cdfe936250, verbosity=0,
    repo=0x6cdfe917070) at got.c:2040
2040                            if (strcmp(local_refname, pe->path) == 0)
(gdb) p local_refname
$1 = 0x0
--8<---------------cut here---------------end--------------->8---

A plain `got fetch' works fine.

I'm using got compiled from the latest commit 9b21d88

Background: (probably not interesting but who knows)

I've deleted a tag server side with `git tag -d 1.0' followed by a `git
gc', then I wanted to pull the change.  After a `got fetch' the tag 1.0
is still there, so I tried with -d and found the crash.

Here's the repo config in case it's useful:

	% cat /home/op/git/vc-got.git/config
	[core]
		repositoryformatversion = 0
		filemode = true
		bare = true
	[remote "origin"]
		url = ssh://git@omarpolo.com/vc-got.git
		fetch = +refs/*:refs/*
		mirror = true
	[remote "github"]
		url = ssh://git@github.com/omar-polo/vc-got
		fetch = +refs/heads/*:refs/remotes/github/*

Thanks,

Omar Polo