Panic in binlog player when merging using SplitClone

[dweitzman]

I attempted a shard merge using SplitClone.

The vreplication row it inserts into _vt.vreplication set "source" to keyspace:"foo" shard:"-80". The binlog player panics (which is recovered, so no tablet crash) if I don't modify it to be keyspace:"foo" shard:"-80" key_range:<>.

E0125 01:31:30.778846 18173 controller.go:143] stream 6: caught panic: runtime error: invalid memory address or nil pointer dereference
/usr/local/go/src/runtime/panic.go:513 (0x42e4e8)
/usr/local/go/src/runtime/panic.go:82 (0x42d63d)
/usr/local/go/src/runtime/signal_unix.go:390 (0x444461)
/vt/src/vitess.io/vitess/go/vt/binlog/binlogplayer/binlog_player.go:236 (0xc033e5)
/vt/src/vitess.io/vitess/go/vt/binlog/binlogplayer/binlog_player.go:177 (0xc01627)
/vt/src/vitess.io/vitess/go/vt/vttablet/tabletmanager/vreplication/controller.go:183 (0xc8a166)
/vt/src/vitess.io/vitess/go/vt/vttablet/tabletmanager/vreplication/controller.go:124 (0xc89b8b)
/usr/local/go/src/runtime/asm_amd64.s:1333 (0x45e730)
W0125 01:31:30.778869 18173 controller.go:134] stream 6: panic: runtime error: invalid memory address or nil pointer dereference, retrying after 5s

Basically, binlog player's keyRange field can be a nil pointer but binlog player dereferences it without first verifying that

[makmanalp]

#4571 merged, should probably close

[GuptaManan100]

Closing the issue. Reopen in case of new developments.