SPIGOT-2891: Remove chunks if first check is false

Minecraft does double checking for synchronous generation, but since we generate chunks asynchronously we are required to check the first condition also in case the chunk was loaded between ticks. We leave the other logic to be cleaned up by the loops below.

nms-patches/PlayerChunkMap.patch

@@ -19,7 +19,19 @@
  
      public PlayerChunkMap(WorldServer worldserver) {
          this.world = worldserver;
-@@ -231,6 +236,16 @@
+@@ -169,7 +174,11 @@
+                             break;
+                         }
+                     }
++                // CraftBukkit start - SPIGOT-2891: remove once chunk has been provided
++                } else {
++                    iterator1.remove();
+                 }
++                // CraftBukkit end
+             }
+         }
+ 
+@@ -231,6 +240,16 @@
          return playerchunk;
      }
  
@@ -36,7 +48,7 @@
      public void flagDirty(BlockPosition blockposition) {
          int i = blockposition.getX() >> 4;
          int j = blockposition.getZ() >> 4;
-@@ -249,12 +264,22 @@
+@@ -249,12 +268,22 @@
          entityplayer.d = entityplayer.locX;
          entityplayer.e = entityplayer.locZ;
  
@@ -60,7 +72,7 @@
          this.managedPlayers.add(entityplayer);
          this.e();
      }
-@@ -298,11 +323,14 @@
+@@ -298,11 +327,14 @@
              int j1 = i - k;
              int k1 = j - l;
  
@@ -76,7 +88,7 @@
                          }
  
                          if (!this.a(l1 - j1, i2 - k1, i, j, i1)) {
-@@ -318,6 +346,13 @@
+@@ -318,6 +350,13 @@
                  entityplayer.d = entityplayer.locX;
                  entityplayer.e = entityplayer.locZ;
                  this.e();
@@ -90,7 +102,7 @@
              }
          }
      }
-@@ -402,4 +437,47 @@
+@@ -402,4 +441,47 @@
          }
  
      }