add tessts for #943 (also, unrelated, move libver to later in the exception)

src/StackExchange.Redis/ExceptionFactory.cs

@@ -200,7 +200,7 @@ void add(string lk, string sk, string v)
                     sb.Append(", ").Append(sk).Append(": ").Append(v);
                 }
             }
-            add("Version", "v", GetLibVersion());
+
             if (server != null)
             {
                 server.GetOutstandingCount(message.Command, out int inst, out int qs, out int @in);
@@ -235,6 +235,8 @@ void add(string lk, string sk, string v)
                 add("Local-CPU", "Local-CPU", PerfCounterHelper.GetSystemCpuPercent());
             }
 
+            add("Version", "v", GetLibVersion());
+
             sb.Append(" (Please take a look at this article for some common client-side issues that can cause timeouts: ");
             sb.Append(timeoutHelpLink);
             sb.Append(")");

src/StackExchange.Redis/PhysicalConnection.cs

@@ -333,7 +333,6 @@ void add(string lk, string sk, string v)
                         data.Add(Tuple.Create(lk, v));
                         exMessage.Append(", ").Append(sk).Append(": ").Append(v);
                     }
-                    add("Version", "v", ExceptionFactory.GetLibVersion());
 
                     if (IncludeDetailInExceptions)
                     {
@@ -370,6 +369,8 @@ void add(string lk, string sk, string v)
                         }
                     }
 
+                    add("Version", "v", ExceptionFactory.GetLibVersion());
+
                     outerException = innerException == null
                         ? new RedisConnectionException(failureType, exMessage.ToString())
                         : new RedisConnectionException(failureType, exMessage.ToString(), innerException);

tests/StackExchange.Redis.Tests/Transactions.cs

@@ -950,5 +950,37 @@ public async Task WatchAbort_HashLengthEqual()
         }
 #endif
 
+        [Fact]
+        public async Task ExecCompletes_Issue943()
+        {
+            int hashHit = 0, hashMiss = 0, expireHit = 0, expireMiss = 0;
+            using (var conn = Create())
+            {
+                var db = conn.GetDatabase();
+                for (int i = 0; i < 40000; i++)
+                {
+                    RedisKey key = Me();
+                    await db.KeyDeleteAsync(key);
+                    HashEntry[] hashEntries = new HashEntry[]
+                    {
+                        new HashEntry("blah", DateTime.UtcNow.ToString("R"))
+                    };
+                    ITransaction transaction = db.CreateTransaction();
+                    ConditionResult keyNotExists = transaction.AddCondition(Condition.KeyNotExists(key));
+                    Task hashSetTask = transaction.HashSetAsync(key, hashEntries);
+                    Task<bool> expireTask = transaction.KeyExpireAsync(key, TimeSpan.FromSeconds(30));
+                    bool committed = await transaction.ExecuteAsync();
+                    if (committed)
+                    {
+                        if (hashSetTask.IsCompleted) hashHit++; else hashMiss++;
+                        if (expireTask.IsCompleted) expireHit++; else expireMiss++;
+                        await hashSetTask;
+                        await expireTask;
+                    }
+                }
+            }
+
+            Writer.WriteLine($"hash hit: {hashHit}, miss: {hashMiss}; expire hit: {expireHit}, miss: {expireMiss}");
+        }
     }
 }