fix: inline assignment instruction from same block (#820)

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

@@ -65,6 +65,7 @@ public abstract class InsnArg extends Typed {
 	}
 
 	private static InsnWrapArg wrap(InsnNode insn) {
+		insn.add(AFlag.WRAPPED);
 		return new InsnWrapArg(insn);
 	}
 
@@ -140,9 +141,17 @@ public abstract class InsnArg extends Typed {
 		InsnArg arg;
 		InsnType type = insn.getType();
 		if (type == InsnType.CONST || type == InsnType.MOVE) {
-			arg = insn.getArg(0);
-			insn.add(AFlag.REMOVE);
-			insn.add(AFlag.DONT_GENERATE);
+			if (insn.contains(AFlag.FORCE_ASSIGN_INLINE)) {
+				RegisterArg resArg = insn.getResult();
+				arg = wrap(insn);
+				if (resArg != null) {
+					arg.setType(resArg.getType());
+				}
+			} else {
+				arg = insn.getArg(0);
+				insn.add(AFlag.REMOVE);
+				insn.add(AFlag.DONT_GENERATE);
+			}
 		} else {
 			arg = wrapArg(insn);
 		}
@@ -156,8 +165,6 @@ public abstract class InsnArg extends Typed {
 	public static InsnArg wrapArg(InsnNode insn) {
 		RegisterArg resArg = insn.getResult();
 		InsnArg arg = wrap(insn);
-		insn.add(AFlag.WRAPPED);
-
 		switch (insn.getType()) {
 			case CONST:
 			case MOVE:

jadx-core/src/main/java/jadx/core/dex/visitors/shrink/CodeShrinkVisitor.java

@@ -100,10 +100,6 @@ public class CodeShrinkVisitor extends AbstractVisitor {
 
 		int assignPos = insnList.getIndex(assignInsn);
 		if (assignPos != -1) {
-			if (assignInline) {
-				// TODO?
-				return;
-			}
 			WrapInfo wrapInfo = argsInfo.checkInline(assignPos, arg);
 			if (wrapInfo != null) {
 				wrapList.add(wrapInfo);
@@ -123,25 +119,19 @@ public class CodeShrinkVisitor extends AbstractVisitor {
 		}
 	}
 
-	private static void assignInline(MethodNode mth, RegisterArg arg, InsnNode assignInsn, BlockNode assignBlock) {
+	private static boolean assignInline(MethodNode mth, RegisterArg arg, InsnNode assignInsn, BlockNode assignBlock) {
 		RegisterArg useArg = arg.getSVar().getUseList().get(0);
 		InsnNode useInsn = useArg.getParentInsn();
 		if (useInsn == null || useInsn.contains(AFlag.DONT_GENERATE)) {
-			return;
-		}
-
-		InsnArg replaceArg;
-		InsnType assignInsnType = assignInsn.getType();
-		if (assignInsnType == InsnType.MOVE || assignInsnType == InsnType.CONST) {
-			replaceArg = assignInsn.getArg(0).duplicate();
-		} else {
-			replaceArg = InsnArg.wrapArg(assignInsn.copy());
+			return false;
 		}
+		InsnArg replaceArg = InsnArg.wrapInsnIntoArg(assignInsn.copy());
 		useInsn.replaceArg(useArg, replaceArg);
 
 		assignInsn.add(AFlag.REMOVE);
 		assignInsn.add(AFlag.DONT_GENERATE);
 		InsnRemover.remove(mth, assignBlock, assignInsn);
+		return true;
 	}
 
 	private static boolean inline(MethodNode mth, RegisterArg arg, InsnNode insn, BlockNode block) {
@@ -149,6 +139,9 @@ public class CodeShrinkVisitor extends AbstractVisitor {
 		if (parentInsn != null && parentInsn.getType() == InsnType.RETURN) {
 			parentInsn.setSourceLine(insn.getSourceLine());
 		}
+		if (insn.contains(AFlag.FORCE_ASSIGN_INLINE)) {
+			return assignInline(mth, arg, insn, block);
+		}
 		boolean replaced = arg.wrapInstruction(mth, insn) != null;
 		if (replaced) {
 			InsnList.remove(block, insn);

jadx-core/src/test/java/jadx/tests/integration/conditions/TestInnerAssign3.java

@@ -0,0 +1,22 @@
+package jadx.tests.integration.conditions;
+
+import org.junit.jupiter.api.Test;
+
+import jadx.tests.api.SmaliTest;
+
+import static jadx.tests.api.utils.assertj.JadxAssertions.assertThat;
+
+/**
+ * Issue #820
+ */
+public class TestInnerAssign3 extends SmaliTest {
+
+	@Test
+	public void test() {
+		disableCompilation();
+		assertThat(getClassNodeFromSmali())
+				.code()
+				.containsOne("(testMethod = (testClass1 = null).testMethod()) == null")
+				.containsOne("testClass1.testField != null");
+	}
+}

jadx-core/src/test/smali/conditions/TestInnerAssign3.smali

@@ -0,0 +1,30 @@
+.class public Lconditions/TestInnerAssign3;
+.super LTestSuper;
+.source "Test.java"
+
+.method public test()V
+    .locals 5
+
+    const/4 v0, 0
+    const/4 v1, 0
+    const/4 v4, 0
+
+    if-eqz v4, :cond_0
+
+    const/4 v2, 0
+
+    invoke-virtual {v2}, LTestClass1;->testMethod()LTestClass2;
+
+    move-result-object v0
+
+    if-eqz v0, :cond_0
+
+    if-eq v1, v0, :cond_0
+
+    iget-object v3, v2, LTestClass1;->testField:LTestClass3;
+
+    if-eqz v3, :cond_0
+
+    :cond_0
+    return-void
+.end method