fix: handle method arguments in primitive types conversion (#956)

jadx-core/src/main/java/jadx/core/dex/instructions/args/RegisterArg.java

@@ -52,12 +52,8 @@ public class RegisterArg extends InsnArg implements Named {
 		sVar.setType(newType);
 	}
 
-	public void updateImmutableType(ArgType type) {
-		if (sVar == null) {
-			throw new JadxRuntimeException("Unknown SSA variable to update immutable type: " + this);
-		}
-		sVar.forceSetType(type);
-		sVar.getAssign().add(AFlag.IMMUTABLE_TYPE);
+	public void forceSetInitType(ArgType type) {
+		this.type = type;
 	}
 
 	@Nullable

jadx-core/src/main/java/jadx/core/dex/instructions/args/SSAVar.java

@@ -8,7 +8,10 @@ import java.util.Set;
 
 import org.jetbrains.annotations.NotNull;
 import org.jetbrains.annotations.Nullable;
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
 
+import jadx.core.Consts;
 import jadx.core.dex.attributes.AFlag;
 import jadx.core.dex.attributes.AType;
 import jadx.core.dex.attributes.nodes.RegDebugInfoAttr;
@@ -21,6 +24,8 @@ import jadx.core.utils.StringUtils;
 import jadx.core.utils.exceptions.JadxRuntimeException;
 
 public class SSAVar {
+	private static final Logger LOG = LoggerFactory.getLogger(SSAVar.class);
+
 	private final int regNum;
 	private final int version;
 
@@ -68,8 +73,8 @@ public class SSAVar {
 
 	@Nullable
 	public ArgType getImmutableType() {
-		if (assign.contains(AFlag.IMMUTABLE_TYPE)) {
-			return assign.getType();
+		if (isTypeImmutable()) {
+			return assign.getInitType();
 		}
 		return null;
 	}
@@ -78,6 +83,17 @@ public class SSAVar {
 		return assign.contains(AFlag.IMMUTABLE_TYPE);
 	}
 
+	public void markAsImmutable(ArgType type) {
+		assign.add(AFlag.IMMUTABLE_TYPE);
+		ArgType initType = assign.getInitType();
+		if (!initType.equals(type)) {
+			assign.forceSetInitType(type);
+			if (Consts.DEBUG_TYPE_INFERENCE) {
+				LOG.debug("Update immutable type at var {} assign with type: {} previous type: {}", this.toShortString(), type, initType);
+			}
+		}
+	}
+
 	public void setType(ArgType type) {
 		ArgType imType = getImmutableType();
 		if (imType != null && !imType.equals(type)) {

jadx-core/src/main/java/jadx/core/dex/visitors/typeinference/TypeInferenceVisitor.java

@@ -803,21 +803,15 @@ public final class TypeInferenceVisitor extends AbstractVisitor {
 
 	private static void assignImmutableTypes(MethodNode mth) {
 		for (SSAVar ssaVar : mth.getSVars()) {
-			ArgType imType = getSsaImmutableType(ssaVar);
-			if (imType != null) {
-				ssaVar.getAssign().updateImmutableType(imType);
+			ArgType immutableType = getSsaImmutableType(ssaVar);
+			if (immutableType != null) {
+				ssaVar.markAsImmutable(immutableType);
 			}
 		}
 	}
 
 	@Nullable
 	private static ArgType getSsaImmutableType(SSAVar ssaVar) {
-		if (ssaVar.isTypeImmutable()) {
-			ArgType type = ssaVar.getTypeInfo().getType();
-			if (type != ArgType.UNKNOWN) {
-				return type;
-			}
-		}
 		if (ssaVar.getAssign().contains(AFlag.IMMUTABLE_TYPE)) {
 			return ssaVar.getAssign().getInitType();
 		}