3 files changed, 36 insertions, 7 deletions

diff --git a/src/main/java/cuchaz/enigma/analysis/JarIndex.java b/src/main/java/cuchaz/enigma/analysis/JarIndex.java
index f955a408..ee1dd544 100644
--- a/src/main/java/cuchaz/enigma/analysis/JarIndex.java
+++ b/src/main/java/cuchaz/enigma/analysis/JarIndex.java
@@ -771,6 +771,14 @@ public class JarIndex {
         return this.access.containsKey(obfBehaviorEntry);
     }
 
+    public boolean containsEntryWithSameName(Entry entry)
+    {
+        for (Entry target : this.access.keySet())
+            if (target.getName().equals(entry.getName()) && entry.getClass().isInstance(target.getClass()))
+                return true;
+        return false;
+    }
+
     public boolean containsObfArgument(ArgumentEntry obfArgumentEntry) {
         // check the behavior
         if (!containsObfBehavior(obfArgumentEntry.getBehaviorEntry())) {
diff --git a/src/main/java/cuchaz/enigma/mapping/Mappings.java b/src/main/java/cuchaz/enigma/mapping/Mappings.java
index 912a57ab..2166bb9f 100644
--- a/src/main/java/cuchaz/enigma/mapping/Mappings.java
+++ b/src/main/java/cuchaz/enigma/mapping/Mappings.java
@@ -15,11 +15,7 @@ import com.google.common.collect.Maps;
 
 import java.io.File;
 import java.io.IOException;
-import java.util.ArrayList;
-import java.util.Collection;
-import java.util.List;
-import java.util.Map;
-import java.util.Set;
+import java.util.*;
 
 import com.google.common.collect.Sets;
 import cuchaz.enigma.analysis.TranslationIndex;
@@ -177,6 +173,16 @@ public class Mappings {
         return classMapping != null && classMapping.containsDeobfField(deobfName, obfType);
     }
 
+    public boolean containsDeobfField(ClassEntry obfClassEntry, String deobfName) {
+        ClassMapping classMapping = this.classesByObf.get(obfClassEntry.getName());
+        if (classMapping != null)
+            for (FieldMapping fieldMapping : classMapping.fields())
+                if (deobfName.equals(fieldMapping.getDeobfName()) || deobfName.equals(fieldMapping.getObfName()))
+                    return true;
+
+        return false;
+    }
+
     public boolean containsDeobfMethod(ClassEntry obfClassEntry, String deobfName, Signature obfSignature) {
         ClassMapping classMapping = this.classesByObf.get(obfClassEntry.getName());
         return classMapping != null && classMapping.containsDeobfMethod(deobfName, obfSignature);
diff --git a/src/main/java/cuchaz/enigma/mapping/MappingsRenamer.java b/src/main/java/cuchaz/enigma/mapping/MappingsRenamer.java
index 5c299e3e..4e812b10 100644
--- a/src/main/java/cuchaz/enigma/mapping/MappingsRenamer.java
+++ b/src/main/java/cuchaz/enigma/mapping/MappingsRenamer.java
@@ -90,8 +90,23 @@ public class MappingsRenamer {
     public void setFieldName(FieldEntry obf, String deobfName) {
         deobfName = NameValidator.validateFieldName(deobfName);
         FieldEntry targetEntry = new FieldEntry(obf.getClassEntry(), deobfName, obf.getType());
-        if (m_mappings.containsDeobfField(obf.getClassEntry(), deobfName, obf.getType()) || m_index.containsObfField(targetEntry)) {
-            throw new IllegalNameException(deobfName, "There is already a field with that name");
+        ClassEntry definedClass = null;
+        if (m_mappings.containsDeobfField(obf.getClassEntry(), deobfName) || m_index.containsEntryWithSameName(targetEntry))
+            definedClass = obf.getClassEntry();
+        else {
+            for (ClassEntry ancestorEntry : this.m_index.getTranslationIndex().getAncestry(obf.getClassEntry())) {
+                if (m_mappings.containsDeobfField(ancestorEntry, deobfName) || m_index.containsEntryWithSameName(targetEntry.cloneToNewClass(ancestorEntry))) {
+                    definedClass = ancestorEntry;
+                    break;
+                }
+            }
+        }
+
+        if (definedClass != null) {
+            String className = m_mappings.getTranslator(TranslationDirection.Deobfuscating, m_index.getTranslationIndex()).translateClass(definedClass.getClassName());
+            if (className == null)
+                className = definedClass.getClassName();
+            throw new IllegalNameException(deobfName, "There is already a field with that name in " + className);
         }
 
         ClassMapping classMapping = getOrCreateClassMapping(obf.getClassEntry());