fix: ignore finally extraction with only one 'if' instruction (#709)

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

@@ -5,6 +5,7 @@ import java.util.HashSet;
 import java.util.List;
 import java.util.Set;
 
+import org.jetbrains.annotations.Nullable;
 import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;
 
@@ -271,13 +272,24 @@ public class MarkFinallyVisitor extends AbstractVisitor {
 		if (dupSlice == null) {
 			return null;
 		}
-		if (dupSlice.isComplete()) {
-			return dupSlice;
-		}
-		if (!checkBlocksTree(dupBlock, startBlock, dupSlice, extractInfo)) {
+		if (!dupSlice.isComplete()
+				&& !checkBlocksTree(dupBlock, startBlock, dupSlice, extractInfo)) {
 			return null;
 		}
-		return dupSlice;
+		return checkSlice(dupSlice);
+	}
+
+	@Nullable
+	private static InsnsSlice checkSlice(InsnsSlice slice) {
+		List<InsnNode> insnsList = slice.getInsnsList();
+		// ignore slice with only one 'if' insn
+		if (insnsList.size() == 1) {
+			InsnNode insnNode = insnsList.get(0);
+			if (insnNode.getType() == InsnType.IF) {
+				return null;
+			}
+		}
+		return slice;
 	}
 
 	/**

jadx-core/src/test/java/jadx/tests/integration/trycatch/TestTryCatchFinally10.java

+package jadx.tests.integration.trycatch;
+
+import org.junit.jupiter.api.Test;
+
+import jadx.core.dex.nodes.ClassNode;
+import jadx.tests.api.SmaliTest;
+
+import static org.hamcrest.CoreMatchers.containsString;
+import static org.hamcrest.MatcherAssert.assertThat;
+import static org.hamcrest.Matchers.not;
+
+public class TestTryCatchFinally10 extends SmaliTest {
+
+	@Test
+	public void test() {
+		disableCompilation();
+		ClassNode cls = getClassNodeFromSmali();
+		String code = cls.getCode().toString();
+
+		assertThat(code, not(containsString("boolean z = null;")));
+	}
+}

jadx-core/src/test/java/jadx/tests/integration/trycatch/TestTryCatchFinally9.java

+package jadx.tests.integration.trycatch;
+
+import java.io.IOException;
+import java.io.InputStream;
+import java.util.Scanner;
+
+import org.junit.jupiter.api.Test;
+
+import jadx.NotYetImplemented;
+import jadx.core.dex.nodes.ClassNode;
+import jadx.tests.api.IntegrationTest;
+
+import static jadx.tests.api.utils.JadxMatchers.containsOne;
+import static org.hamcrest.CoreMatchers.containsString;
+import static org.hamcrest.MatcherAssert.assertThat;
+import static org.hamcrest.Matchers.not;
+
+public class TestTryCatchFinally9 extends IntegrationTest {
+
+	public static class TestCls {
+		public String test() throws IOException {
+			InputStream input = null;
+			try {
+				input = this.getClass().getResourceAsStream("resource");
+				Scanner scanner = new Scanner(input).useDelimiter("\\A");
+				return scanner.hasNext() ? scanner.next() : "";
+			} finally {
+				if (input != null) {
+					input.close();
+				}
+			}
+		}
+	}
+
+	@Test
+	@NotYetImplemented("finally extraction")
+	public void test() {
+		ClassNode cls = getClassNode(TestCls.class);
+		String code = cls.getCode().toString();
+
+		assertThat(code, not(containsString("JADX INFO: finally extract failed")));
+		assertThat(code, not(containsString("throw")));
+		assertThat(code, containsOne("} finally {"));
+		assertThat(code, containsOne("if (input != null) {"));
+	}
+}

jadx-core/src/test/smali/trycatch/TestTryCatchFinally10.smali

+.class public Ltrycatch/TestTryCatchFinally10;
+.super Ljava/lang/Object;
+
+
+# static fields
+.field private static final l:Llog/DebugLogger;
+
+.method public static test(Landroid/content/Context;I)Ljava/lang/String;
+    .locals 2
+
+    .line 46
+    invoke-static {p0}, LCommonContracts;->requireNonNull(Ljava/lang/Object;)V
+
+    const/4 v0, 0x0
+
+    .line 50
+    :try_start_0
+    invoke-virtual {p0}, Landroid/content/Context;->getResources()Landroid/content/res/Resources;
+
+    move-result-object p0
+
+    invoke-virtual {p0, p1}, Landroid/content/res/Resources;->openRawResource(I)Ljava/io/InputStream;
+
+    move-result-object v0
+
+    .line 51
+    new-instance p0, Ljava/util/Scanner;
+
+    invoke-direct {p0, v0}, Ljava/util/Scanner;-><init>(Ljava/io/InputStream;)V
+
+    const-string p1, "\\A"
+
+    invoke-virtual {p0, p1}, Ljava/util/Scanner;->useDelimiter(Ljava/lang/String;)Ljava/util/Scanner;
+
+    move-result-object p0
+
+    .line 52
+    invoke-virtual {p0}, Ljava/util/Scanner;->hasNext()Z
+
+    move-result p1
+
+    if-eqz p1, :cond_0
+
+    invoke-virtual {p0}, Ljava/util/Scanner;->next()Ljava/lang/String;
+
+    move-result-object p0
+
+    goto :goto_0
+
+    :cond_0
+    const-string p0, ""
+    :try_end_0
+    .catchall {:try_start_0 .. :try_end_0} :catchall_0
+
+    :goto_0
+    if-eqz v0, :cond_1
+
+    .line 56
+    :try_start_1
+    invoke-virtual {v0}, Ljava/io/InputStream;->close()V
+    :try_end_1
+    .catch Ljava/io/IOException; {:try_start_1 .. :try_end_1} :catch_0
+
+    goto :goto_1
+
+    :catch_0
+    move-exception p1
+
+    .line 58
+    sget-object v0, Ltrycatch/TestTryCatchFinally10;->l:Llog/DebugLogger;
+
+    sget-object v1, Llog/DebugLogger$LogLevel;->ERROR:Llog/DebugLogger$LogLevel;
+
+    invoke-virtual {v0, v1, p1}, Llog/DebugLogger;->logException(Llog/DebugLogger$LogLevel;Ljava/lang/Exception;)V
+
+    :cond_1
+    :goto_1
+    return-object p0
+
+    :catchall_0
+    move-exception p0
+
+    if-eqz v0, :cond_2
+
+    .line 56
+    :try_start_2
+    invoke-virtual {v0}, Ljava/io/InputStream;->close()V
+    :try_end_2
+    .catch Ljava/io/IOException; {:try_start_2 .. :try_end_2} :catch_1
+
+    goto :goto_2
+
+    :catch_1
+    move-exception p1
+
+    .line 58
+    sget-object v0, Ltrycatch/TestTryCatchFinally10;->l:Llog/DebugLogger;
+
+    sget-object v1, Llog/DebugLogger$LogLevel;->ERROR:Llog/DebugLogger$LogLevel;
+
+    invoke-virtual {v0, v1, p1}, Llog/DebugLogger;->logException(Llog/DebugLogger$LogLevel;Ljava/lang/Exception;)V
+
+    .line 61
+    :cond_2
+    :goto_2
+    throw p0
+.end method