[WIP sales] make storage available again upon failure

codex/sales.nim

@@ -153,6 +153,7 @@ proc start(negotiation: Negotiation) {.async.} =
     negotiation.waiting = some negotiation.waitForExpiry()
   except CatchableError as e:
     error "Negotiation failed", msg = e.msg
+    negotiation.finish(success = false)
 
 proc handleRequest(sales: Sales, requestId: array[32, byte], ask: StorageAsk) =
   without availability =? sales.findAvailability(ask):

tests/codex/testsales.nim

@@ -80,6 +80,13 @@ suite "Sales":
     discard await market.requestStorage(request)
     check retrievingCid == request.content.cid
 
+  test "makes storage available again when data retrieval fails":
+    let error = newException(IOError, "data retrieval failed")
+    sales.retrieve = proc(cid: string) {.async.} = raise error
+    sales.add(availability)
+    discard await market.requestStorage(request)
+    check sales.available == @[availability]
+
   test "generates proof of storage":
     var provingCid: string
     sales.prove = proc(cid: string): Future[seq[byte]] {.async.} = provingCid = cid