core: always inline 'this' (issue #10)

jadx-core/src/main/java/jadx/core/dex/visitors/CodeShrinker.java

@@ -192,7 +192,11 @@ public class CodeShrinker extends AbstractVisitor {
 //					continue;
 //				}
 				SSAVar sVar = arg.getSVar();
-				if (sVar.getAssign() == null || sVar.getVariableUseCount() != 1) {
+				if (sVar.getAssign() == null) {
+					continue;
+				}
+				// allow inline only one use arg or 'this'
+				if (sVar.getVariableUseCount() != 1 && !arg.isThis()) {
 					continue;
 				}
 				InsnNode assignInsn = sVar.getAssign().getParentInsn();

jadx-core/src/test/java/jadx/tests/internal/usethis/TestInlineThis.java

@@ -0,0 +1,42 @@
+package jadx.tests.internal.usethis;
+
+import jadx.api.InternalJadxTest;
+import jadx.core.dex.nodes.ClassNode;
+
+import org.junit.Test;
+
+import static jadx.tests.utils.JadxMatchers.containsOne;
+import static org.hamcrest.CoreMatchers.containsString;
+import static org.hamcrest.CoreMatchers.not;
+import static org.junit.Assert.assertThat;
+
+public class TestInlineThis extends InternalJadxTest {
+
+	public static class TestCls {
+		public int field;
+
+		private void test() {
+			TestCls something = this;
+			something.method();
+			something.field = 123;
+		}
+
+		private void method() {
+		}
+	}
+
+	@Test
+	public void test() {
+		ClassNode cls = getClassNode(TestCls.class);
+		String code = cls.getCode().toString();
+		System.out.println(code);
+
+		assertThat(code, not(containsString("something")));
+		assertThat(code, not(containsString("something.method()")));
+		assertThat(code, not(containsString("something.field")));
+		assertThat(code, not(containsString("= this")));
+
+		assertThat(code, containsOne("this.field = 123;"));
+		assertThat(code, containsOne("method();"));
+	}
+}

jadx-core/src/test/java/jadx/tests/internal/usethis/TestRedundantThis.java

@@ -1,4 +1,4 @@
-package jadx.tests.internal;
+package jadx.tests.internal.usethis;
 
 import jadx.api.InternalJadxTest;
 import jadx.core.dex.nodes.ClassNode;
@@ -30,7 +30,6 @@ public class TestRedundantThis extends InternalJadxTest {
 	// @Test
 	public void test() {
 		ClassNode cls = getClassNode(TestCls.class);
-
 		String code = cls.getCode().toString();
 
 		assertThat(code, not(containsString("this.f1();")));