Crash in DMap Get after cluster node restarts

[cobexer]

http: panic serving 127.0.0.1:43120: runtime error: invalid memory address or nil pointer dereference
goroutine 354448 [running]:
net/http.(*conn).serve.func1(0xc00013e000)
	/usr/local/go/src/net/http/server.go:1801 +0x147
panic(0x2482ea0, 0x3f77bb0)
	/usr/local/go/src/runtime/panic.go:975 +0x3e9
github.com/buraksezer/olric/internal/protocol.(*DMapMessage).SetBuffer(0x0, 0xc005a6dc50)
	/go/pkg/mod/github.com/buraksezer/olric@v0.3.0-beta.4/internal/protocol/dmap.go:128 +0x20
github.com/buraksezer/olric/internal/transport.(*Client).RequestTo(0xc0000d0a00, 0xc00247bbe0, 0x12, 0x2dd63a0, 0x0, 0x0, 0x0, 0x0, 0x0)
	/go/pkg/mod/github.com/buraksezer/olric@v0.3.0-beta.4/internal/transport/client.go:236 +0x174
github.com/buraksezer/olric.(*Olric).requestTo(0xc0004ad8c0, 0xc00247bbe0, 0x12, 0x2dd63a0, 0x0, 0x4, 0x2, 0x97, 0xc005de62c0)
	/go/pkg/mod/github.com/buraksezer/olric@v0.3.0-beta.4/olric.go:465 +0x6a
github.com/buraksezer/olric.(*Olric).readRepair(0xc0004ad8c0, 0x29cdf9c, 0x7, 0xc000765230, 0xc006acf700, 0xc001dc5080, 0x2, 0x2)
	/go/pkg/mod/github.com/buraksezer/olric@v0.3.0-beta.4/dmap_get.go:208 +0x408
github.com/buraksezer/olric.(*Olric).callGetOnCluster(0xc0004ad8c0, 0xb996eaeb6dea11fb, 0x29cdf9c, 0x7, 0xc005002dc0, 0x48, 0x10, 0x3fe9df4bb343ca0c, 0x163bfafaf7a57943, 0xb996eaeb6dea11fb, ...)
	/go/pkg/mod/github.com/buraksezer/olric@v0.3.0-beta.4/dmap_get.go:263 +0x458
github.com/buraksezer/olric.(*Olric).get(0xc0004ad8c0, 0x29cdf9c, 0x7, 0xc005002dc0, 0x48, 0x0, 0xc002121080, 0x58, 0xc002121088, 0xc00500e00c)
	/go/pkg/mod/github.com/buraksezer/olric@v0.3.0-beta.4/dmap_get.go:272 +0x267
github.com/buraksezer/olric.(*DMap).Get(0xc0006b65c0, 0xc005002dc0, 0x48, 0x9, 0xc002121108, 0x0, 0x7)
	/go/pkg/mod/github.com/buraksezer/olric@v0.3.0-beta.4/dmap_get.go:291 +0x58
example.com/container-id-to-image-cache/internal/kvcache.(*KVCache).Get(...)
	/build/internal/kvcache/kvcache.go:112
example.com/container-id-to-image-cache/internal/rest.(*API).handleLookup.func1(0x2dae280, 0xc002c6f040, 0xc00500c000)
	/build/internal/rest/restapi.go:65 +0x93
net/http.HandlerFunc.ServeHTTP(0xc000734a80, 0x2dae280, 0xc002c6f040, 0xc00500c000)
	/usr/local/go/src/net/http/server.go:2042 +0x44
net/http.(*ServeMux).ServeHTTP(0x3fb20c0, 0x2dae280, 0xc002c6f040, 0xc00500c000)
	/usr/local/go/src/net/http/server.go:2417 +0x1ad
github.com/gorilla/handlers.loggingHandler.ServeHTTP(0x2d66560, 0xc00000e018, 0x2d66200, 0x3fb20c0, 0x2acdcd0, 0x2dacdc0, 0xc000d8a2a0, 0xc00500c000)
	/go/pkg/mod/github.com/gorilla/handlers@v1.5.1/logging.go:47 +0xe6
github.com/gorilla/handlers.ProxyHeaders.func1(0x2dacdc0, 0xc000d8a2a0, 0xc00500c000)
	/go/pkg/mod/github.com/gorilla/handlers@v1.5.1/proxy_headers.go:59 +0x114
net/http.HandlerFunc.ServeHTTP(0xc00072b8c0, 0x2dacdc0, 0xc000d8a2a0, 0xc00500c000)
	/usr/local/go/src/net/http/server.go:2042 +0x44
net/http.serverHandler.ServeHTTP(0xc000648000, 0x2dacdc0, 0xc000d8a2a0, 0xc00500c000)
	/usr/local/go/src/net/http/server.go:2843 +0xa3
net/http.(*conn).serve(0xc00013e000, 0x2db2ac0, 0xc002c1f540)
	/usr/local/go/src/net/http/server.go:1925 +0x8ad
created by net/http.(*Server).Serve
	/usr/local/go/src/net/http/server.go:2969 +0x36c

If I checked this correctly this is because of:

olric/dmap_get.go

Line 181 in 003e447

req := protocol.NewDMapMessage(protocol.OpPutExReplica)

which uses req := instead of just req = and thus passes a nil req into db.requestTo causing the crash.

[buraksezer]

Fixed in 63c6d11

Please feel free to reopen this issue, if you encounter the problem again.