runtime error when query

[QianchaoLiu]

If you suspect this could be a bug, follow the template.

• What version of Dgraph are you using?

Dgraph version : v1.0.5
Commit SHA-1 : 8278741
Commit timestamp : 2018-04-20 15:50:53 +1000
Branch : HEAD

• Have you tried reproducing the issue with latest release?
  yes

• What is the hardware spec (RAM, OS)?
  Ubuntu16, 128G RAM

• Steps to reproduce the issue (command/config used to run Dgraph).

{
  getQuery(func: eq(address, "1BjGc3HpMRLccR73uGidJxhhxXW8udVHFP")){
    address
  }
}

when change 1BjGc3HpMRLccR73uGidJxhhxXW8udVHFP to something else, I do not meet this problem.

In another server, I try to reproduce the same problem. However, it works well. Therefore, I thought it is related with error during insert this address. After the failure of mutate, this address can never be queried.

At the same time, I use allOfTerms take replace of eq, there is no problem. When I try to delete this node using uid I got message: Unable to read from value log: {Fid:29 Len:107 Offset:671977240}: Unable to find log file. Please retry

• Expected behaviour and actual result.

panic: runtime error: invalid memory address or nil pointer dereference
[signal SIGSEGV: segmentation violation code=0x1 addr=0x0 pc=0x10125b8]

goroutine 267052 [running]:
github.com/dgraph-io/dgraph/posting.(*List).Value(0x0, 0x3b8f27b, 0x0, 0x0, 0x0, 0x0, 0x0)
        /home/travis/gopath/src/github.com/dgraph-io/dgraph/posting/list.go:935 +0x58
github.com/dgraph-io/dgraph/worker.handleCompareFunction.func1(0x14ddba, 0x0, 0xc470c326d0)
        /home/travis/gopath/src/github.com/dgraph-io/dgraph/worker/task.go:911 +0x31f
github.com/dgraph-io/dgraph/algo.ApplyFilter(0xc470c55f20, 0xc480aa7838)
        /home/travis/gopath/src/github.com/dgraph-io/dgraph/algo/uidlist.go:24 +0xb3
github.com/dgraph-io/dgraph/worker.handleCompareFunction(0x1a821e0, 0xc470c3be00, 0xc470d68000, 0x1, 0xc470c5a9a0, 0xc470c527e0, 0x3b8f27b, 0x0)
        /home/travis/gopath/src/github.com/dgraph-io/dgraph/worker/task.go:888 +0x4d2
github.com/dgraph-io/dgraph/worker.helpProcessTask(0x1a821e0, 0xc470c3be00, 0xc470d68000, 0x1, 0x0, 0x0, 0x139b2d8)
        /home/travis/gopath/src/github.com/dgraph-io/dgraph/worker/task.go:715 +0x429
github.com/dgraph-io/dgraph/worker.processTask(0x1a821e0, 0xc470c3be00, 0xc470d68000, 0x1, 0xc470a7ce00, 0xc470d68000, 0xc467c9db48)
        /home/travis/gopath/src/github.com/dgraph-io/dgraph/worker/task.go:626 +0x1be
github.com/dgraph-io/dgraph/worker.ProcessTaskOverNetwork(0x1a821e0, 0xc470c3be00, 0xc470d68000, 0x0, 0xffffffffffffffff, 0xc46e2e5000)
        /home/travis/gopath/src/github.com/dgraph-io/dgraph/worker/task.go:149 +0x546
github.com/dgraph-io/dgraph/query.ProcessGraph(0x1a821e0, 0xc470c3be00, 0xc470c462c0, 0x0, 0xc4708cf200)