Fix Depth 1 bug at very low time controls, some fishtesting workers, and delayed move senders like Arena.

Non-Regression STC:

LLR: 2.94 (-2.94,2.94) <-1.75,0.25>
Total: 98208 W: 25423 L: 25276 D: 47509
Ptnml(0-2): 271, 10713, 26994, 10850, 276
https://tests.stockfishchess.org/tests/view/69ad43c21d849c824c6afe82

-

Hell VVSTC (0.2+0.02)
LLR: 2.70 (-2.94,2.94) <0.00,2.00>
Total: 688 W: 660 L: 11 D: 17
Ptnml(0-2): 1, 0, 10, 15, 318
https://tests.stockfishchess.org/tests/view/69ae4bea1d849c824c6b00b0

-

Sudden Death (1+0)

LLR: 2.19 (-2.94,2.94) <-1.75,0.25>
Total: 538 W: 536 L: 0 D: 2
Ptnml(0-2): 0, 0, 0, 2, 267
https://tests.stockfishchess.org/tests/live_elo/69ae6c031d849c824c6b00dc

-

Sudden Death (5+0)

LLR: 2.94 (-2.94,2.94) <-1.75,0.25>
Total: 22248 W: 6058 L: 5802 D: 10388
Ptnml(0-2): 214, 2420, 5583, 2710, 197
https://tests.stockfishchess.org/tests/view/69ae6dd01d849c824c6b00ee

-

Fixes #6639

closes https://github.com/official-stockfish/Stockfish/pull/6659

No functional change

AUTHORS

@@ -266,6 +266,7 @@ Uri Blass (uriblass)
 Vince Negri (cuddlestmonkey)
 Viren
 Wencey Wang
+Will Miles (willm)
 windfishballad
 xefoci7612
 Xiang Wang (KatyushaScarlet)

src/timeman.cpp

@@ -129,9 +129,10 @@ void TimeManagement::init(Search::LimitsType& limits,
     }
 
     // Limit the maximum possible time for this move
-    optimumTime = TimePoint(optScale * timeLeft);
+    optimumTime = TimePoint(std::max(1.0, optScale * timeLeft));
     maximumTime =
-      TimePoint(std::min(0.825179 * limits.time[us] - moveOverhead, maxScale * optimumTime)) - 10;
+      TimePoint(std::max(double(optimumTime), std::min(0.825179 * limits.time[us] - moveOverhead,
+                                                       maxScale * optimumTime)));
 
     if (options["Ponder"])
         optimumTime += optimumTime / 4;