Fix item resolution query crashing on some enchant books (#262)

2 files changed, 38 insertions, 2 deletions

diff --git a/src/main/java/io/github/moulberry/notenoughupdates/util/ItemResolutionQuery.java b/src/main/java/io/github/moulberry/notenoughupdates/util/ItemResolutionQuery.java
index 1ff659ac..48eb6fad 100644
--- a/src/main/java/io/github/moulberry/notenoughupdates/util/ItemResolutionQuery.java
+++ b/src/main/java/io/github/moulberry/notenoughupdates/util/ItemResolutionQuery.java
@@ -194,14 +194,14 @@ public class ItemResolutionQuery {
 
 	private String resolveEnchantedBookNameFromNBT() {
 		NBTTagCompound enchantments = getExtraAttributes().getCompoundTag("enchantments");
-		String enchantName = Iterables.getOnlyElement(enchantments.getKeySet(), null);
+		String enchantName = IteratorUtils.getOnlyElement(enchantments.getKeySet(), null);
 		if (enchantName == null || enchantName.isEmpty()) return null;
 		return enchantName.toUpperCase(Locale.ROOT) + ";" + enchantments.getInteger(enchantName);
 	}
 
 	private String resolveRuneName() {
 		NBTTagCompound runes = getExtraAttributes().getCompoundTag("runes");
-		String runeName = Iterables.getOnlyElement(runes.getKeySet(), null);
+		String runeName = IteratorUtils.getOnlyElement(runes.getKeySet(), null);
 		if (runeName == null || runeName.isEmpty()) return null;
 		return runeName.toUpperCase(Locale.ROOT) + "_RUNE;" + runes.getInteger(runeName);
 	}
diff --git a/src/main/java/io/github/moulberry/notenoughupdates/util/IteratorUtils.java b/src/main/java/io/github/moulberry/notenoughupdates/util/IteratorUtils.java
new file mode 100644
index 00000000..32cd5fad
--- /dev/null
+++ b/src/main/java/io/github/moulberry/notenoughupdates/util/IteratorUtils.java
@@ -0,0 +1,36 @@
+/*
+ * Copyright (C) 2022 NotEnoughUpdates contributors
+ *
+ * This file is part of NotEnoughUpdates.
+ *
+ * NotEnoughUpdates is free software: you can redistribute it
+ * and/or modify it under the terms of the GNU Lesser General Public
+ * License as published by the Free Software Foundation, either
+ * version 3 of the License, or (at your option) any later version.
+ *
+ * NotEnoughUpdates is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
+ * Lesser General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public License
+ * along with NotEnoughUpdates. If not, see <https://www.gnu.org/licenses/>.
+ */
+
+package io.github.moulberry.notenoughupdates.util;
+
+import java.util.Iterator;
+
+public class IteratorUtils {
+
+	public static <T> T getOnlyElement(Iterator<T> it, T defaultValue) {
+		if (!it.hasNext()) return defaultValue;
+		T ret = it.next();
+		if (it.hasNext()) return defaultValue;
+		return ret;
+	}
+
+	public static <T> T getOnlyElement(Iterable<T> it, T defaultValue) {
+		return getOnlyElement(it.iterator(), defaultValue);
+	}
+}