Always use .equals for comparing RegisterType instances

baksmali/src/main/java/org/jf/baksmali/Adaptors/PostInstructionRegisterInfoMethodItem.java

@@ -75,8 +75,8 @@ public class PostInstructionRegisterInfoMethodItem extends MethodItem {
 
     private void addDestRegs(BitSet printPostRegister, int registerCount) {
         for (int registerNum=0; registerNum<registerCount; registerNum++) {
-            if (analyzedInstruction.getPreInstructionRegisterType(registerNum) !=
+            if (!analyzedInstruction.getPreInstructionRegisterType(registerNum).equals(
-                    analyzedInstruction.getPostInstructionRegisterType(registerNum)) {
+                    analyzedInstruction.getPostInstructionRegisterType(registerNum))) {
                 printPostRegister.set(registerNum);
             }
         }

baksmali/src/main/java/org/jf/baksmali/Adaptors/PreInstructionRegisterInfoMethodItem.java

@@ -151,7 +151,7 @@ public class PreInstructionRegisterInfoMethodItem extends MethodItem {
             RegisterType mergedRegisterType = analyzedInstruction.getPreInstructionRegisterType(registerNum);
 
             for (AnalyzedInstruction predecessor: analyzedInstruction.getPredecessors()) {
-                if (predecessor.getPostInstructionRegisterType(registerNum) != mergedRegisterType) {
+                if (!predecessor.getPostInstructionRegisterType(registerNum).equals(mergedRegisterType)) {
                     registers.set(registerNum);
                 }
             }
@@ -178,7 +178,7 @@ public class PreInstructionRegisterInfoMethodItem extends MethodItem {
             for (AnalyzedInstruction predecessor: analyzedInstruction.getPredecessors()) {
                 RegisterType predecessorRegisterType = predecessor.getPostInstructionRegisterType(registerNum);
                 if (predecessorRegisterType.category != RegisterType.UNKNOWN &&
-                        predecessorRegisterType != mergedRegisterType) {
+                        !predecessorRegisterType.equals(mergedRegisterType)) {
 
                     addRegister = true;
                     break;

baksmali/src/test/java/org/jf/baksmali/AnalysisTest.java

@@ -56,6 +56,11 @@ public class AnalysisTest {
         runTest("ConstructorTest");
     }
 
+    @Test
+    public void RegisterEqualityOnMergeTest() throws IOException, URISyntaxException {
+        runTest("RegisterEqualityOnMergeTest");
+    }
+
     public void runTest(String test) throws IOException, URISyntaxException {
         String dexFilePath = String.format("%s%sclasses.dex", test, File.separatorChar);
 

baksmali/src/test/resources/ConstructorTest/out/ConstructorTest.smali

@@ -1,12 +0,0 @@
-.class public LConstructorTest;
-.super Ljava/lang/Object;
-
-
-# direct methods
-.method public constructor <init>()V
-    .registers 4
-
-    invoke-direct {p0}, Ljava/lang/Object;-><init>()V
-
-    return-void
-.end method

baksmali/src/test/resources/ConstructorTest/out/ConstructorTest2.smali

@@ -1,17 +0,0 @@
-.class public LConstructorTest2;
-.super Ljava/lang/Object;
-
-
-# direct methods
-.method public constructor <init>()V
-    .registers 4
-
-    if-eqz p0, :cond_3
-
-    nop
-
-    :cond_3
-    invoke-direct {p0}, Ljava/lang/Object;-><init>()V
-
-    return-void
-.end method

baksmali/src/test/resources/RegisterEqualityOnMergeTest/RegisterEqualityOnMerge.smali

@@ -0,0 +1,37 @@
+.class public LRegisterEqualityOnMerge;
+.super Ljava/lang/Object;
+
+
+# direct methods
+.method public constructor <init>()V
+    .registers 4
+
+    #v0=(Uninit);v1=(Uninit);v2=(Uninit);p0=(UninitThis,LRegisterEqualityOnMerge;);
+    invoke-direct {p0}, Ljava/lang/Object;-><init>()V
+    #v0=(Uninit);v1=(Uninit);v2=(Uninit);p0=(Reference,LRegisterEqualityOnMerge;);
+
+    #v0=(Uninit);v1=(Uninit);v2=(Uninit);p0=(Reference,LRegisterEqualityOnMerge;);
+    invoke-virtual {p0}, Ljava/lang/Object;->toString()Ljava/lang/String;
+    #v0=(Uninit);v1=(Uninit);v2=(Uninit);p0=(Reference,LRegisterEqualityOnMerge;);
+
+    #v0=(Uninit);v1=(Uninit);v2=(Uninit);p0=(Reference,LRegisterEqualityOnMerge;);
+    move-result-object v0
+    #v0=(Reference,Ljava/lang/String;);v1=(Uninit);v2=(Uninit);p0=(Reference,LRegisterEqualityOnMerge;);
+
+    #v0=(Reference,Ljava/lang/String;);v1=(Uninit);v2=(Uninit);p0=(Reference,LRegisterEqualityOnMerge;);
+    if-eqz v0, :cond_d
+    #v0=(Reference,Ljava/lang/String;);v1=(Uninit);v2=(Uninit);p0=(Reference,LRegisterEqualityOnMerge;);
+
+    #v0=(Reference,Ljava/lang/String;);v1=(Uninit);v2=(Uninit);p0=(Reference,LRegisterEqualityOnMerge;);
+    invoke-virtual {p0}, Ljava/lang/Object;->toString()Ljava/lang/String;
+    #v0=(Reference,Ljava/lang/String;);v1=(Uninit);v2=(Uninit);p0=(Reference,LRegisterEqualityOnMerge;);
+
+    #v0=(Reference,Ljava/lang/String;);v1=(Uninit);v2=(Uninit);p0=(Reference,LRegisterEqualityOnMerge;);
+    move-result-object v0
+    #v0=(Reference,Ljava/lang/String;);v1=(Uninit);v2=(Uninit);p0=(Reference,LRegisterEqualityOnMerge;);
+
+    :cond_d
+    #v0=(Reference,Ljava/lang/String;);v1=(Uninit);v2=(Uninit);p0=(Reference,LRegisterEqualityOnMerge;);
+    return-void
+    #v0=(Reference,Ljava/lang/String;);v1=(Uninit);v2=(Uninit);p0=(Reference,LRegisterEqualityOnMerge;);
+.end method

dexlib2/src/main/java/org/jf/dexlib2/analysis/AnalyzedInstruction.java

@@ -176,7 +176,7 @@ public class AnalyzedInstruction implements Comparable<AnalyzedInstruction> {
         RegisterType oldRegisterType = preRegisterMap[registerNumber];
         RegisterType mergedRegisterType = oldRegisterType.merge(registerType);
 
-        if (mergedRegisterType == oldRegisterType) {
+        if (mergedRegisterType.equals(oldRegisterType)) {
             return false;
         }
 
@@ -218,7 +218,7 @@ public class AnalyzedInstruction implements Comparable<AnalyzedInstruction> {
          assert registerType != null;
 
          RegisterType oldRegisterType = postRegisterMap[registerNumber];
-         if (oldRegisterType == registerType) {
+         if (oldRegisterType.equals(registerType)) {
              return false;
          }
 
@@ -277,7 +277,7 @@ public class AnalyzedInstruction implements Comparable<AnalyzedInstruction> {
                 return false;
             }
             //check if the uninit ref has been copied to another register
-            if (getPreInstructionRegisterType(registerNumber) == preInstructionDestRegisterType) {
+            if (getPreInstructionRegisterType(registerNumber).equals(preInstructionDestRegisterType)) {
                 return true;
             }
             return false;

dexlib2/src/main/java/org/jf/dexlib2/analysis/MethodAnalyzer.java

@@ -1253,7 +1253,7 @@ public class MethodAnalyzer {
                 if (preInstructionRegisterType.category == RegisterType.UNINIT_REF ||
                         preInstructionRegisterType.category == RegisterType.UNINIT_THIS) {
                     RegisterType registerType;
-                    if (preInstructionRegisterType == objectRegisterType) {
+                    if (preInstructionRegisterType.equals(objectRegisterType)) {
                         registerType = analyzedInstruction.postRegisterMap[objectRegister];
                     } else {
                         registerType = preInstructionRegisterType;

dexlib2/src/main/java/org/jf/dexlib2/analysis/RegisterType.java

@@ -264,7 +264,7 @@ public class RegisterType {
 
     @Nonnull
     public RegisterType merge(@Nonnull RegisterType other) {
-        if (other == this) {
+        if (other.equals(this)) {
             return this;
         }