Fix NPE and uuid lookup for player skulls

Fixes #3610
Fixes #3611

Spigot-Server-Patches/0154-Basic-PlayerProfile-API.patch

@@ -7,10 +7,10 @@ Establishes base extension of profile systems for future edits too
 
 diff --git a/src/main/java/com/destroystokyo/paper/profile/CraftPlayerProfile.java b/src/main/java/com/destroystokyo/paper/profile/CraftPlayerProfile.java
 new file mode 100644
-index 0000000000000000000000000000000000000000..00b7630ccb2be7a78ab5471c8e8bdcd5a92209a0
+index 0000000000000000000000000000000000000000..d73de9eb89c4e3a748907f2da21a3072cc6b7f41
 --- /dev/null
 +++ b/src/main/java/com/destroystokyo/paper/profile/CraftPlayerProfile.java
-@@ -0,0 +1,294 @@
+@@ -0,0 +1,296 @@
 +package com.destroystokyo.paper.profile;
 +
 +import com.destroystokyo.paper.PaperConfig;
@@ -194,13 +194,15 @@ index 0000000000000000000000000000000000000000..00b7630ccb2be7a78ab5471c8e8bdcd5
 +    public boolean complete(boolean textures, boolean onlineMode) {
 +        MinecraftServer server = MinecraftServer.getServer();
 +
-+        boolean isCompleteFromCache = this.completeFromCache(false, onlineMode);
++        boolean isCompleteFromCache = this.completeFromCache(true, onlineMode);
 +        if (onlineMode && (!isCompleteFromCache || textures && !hasTextures())) {
 +            GameProfile result = server.getSessionService().fillProfileProperties(profile, true);
 +            if (result != null) {
 +                copyProfileProperties(result, this.profile, true);
 +            }
-+            server.getUserCache().saveProfile(this.profile);
++            if (this.profile.isComplete()) {
++                server.getUserCache().saveProfile(this.profile);
++            }
 +        }
 +        return profile.isComplete() && (!onlineMode || !textures || hasTextures());
 +    }