From 5c75f249c736d819b04138c3e86a54c54b6839ac Mon Sep 17 00:00:00 2001
From: Jonas Konrad <me@yawk.at>
Date: Tue, 1 Dec 2020 11:39:48 +0100
Subject: [PATCH] fix: do not count nop instructions when considering methods
 for fallback mode printing (#1038) (PR #1039)

---
 .../java/jadx/core/codegen/MethodGen.java     |   8 +-
 .../fallback/TestFallbackManyNops.java        |  27 ++++
 .../smali/fallback/TestFallbackManyNops.smali | 117 ++++++++++++++++++
 3 files changed, 151 insertions(+), 1 deletion(-)
 create mode 100644 jadx-core/src/test/java/jadx/tests/integration/fallback/TestFallbackManyNops.java
 create mode 100644 jadx-core/src/test/smali/fallback/TestFallbackManyNops.smali

diff --git a/jadx-core/src/main/java/jadx/core/codegen/MethodGen.java b/jadx-core/src/main/java/jadx/core/codegen/MethodGen.java
index e6b63a2d..786d0a63 100644
--- a/jadx-core/src/main/java/jadx/core/codegen/MethodGen.java
+++ b/jadx-core/src/main/java/jadx/core/codegen/MethodGen.java
@@ -3,6 +3,8 @@ package jadx.core.codegen;
 import java.util.Collections;
 import java.util.Iterator;
 import java.util.List;
+import java.util.Objects;
+import java.util.stream.Stream;
 
 import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;
@@ -290,7 +292,11 @@ public class MethodGen {
 			code.startLine("// Can't load method instructions.");
 			return;
 		}
-		if (insnArr.length > 100) {
+		long insnCountEstimate = Stream.of(insnArr)
+				.filter(Objects::nonNull)
+				.filter(insn -> insn.getType() != InsnType.NOP)
+				.count();
+		if (insnCountEstimate > 100) {
 			code.startLine("// Method dump skipped, instructions count: " + insnArr.length);
 			return;
 		}
diff --git a/jadx-core/src/test/java/jadx/tests/integration/fallback/TestFallbackManyNops.java b/jadx-core/src/test/java/jadx/tests/integration/fallback/TestFallbackManyNops.java
new file mode 100644
index 00000000..54d72a3b
--- /dev/null
+++ b/jadx-core/src/test/java/jadx/tests/integration/fallback/TestFallbackManyNops.java
@@ -0,0 +1,27 @@
+package jadx.tests.integration.fallback;
+
+import org.junit.jupiter.api.Test;
+
+import jadx.core.dex.nodes.ClassNode;
+import jadx.tests.api.SmaliTest;
+
+import static jadx.tests.api.utils.JadxMatchers.containsOne;
+import static org.hamcrest.CoreMatchers.containsString;
+import static org.hamcrest.CoreMatchers.not;
+import static org.hamcrest.MatcherAssert.assertThat;
+
+public class TestFallbackManyNops extends SmaliTest {
+
+	@Test
+	public void test() {
+		setFallback();
+		disableCompilation();
+
+		ClassNode cls = getClassNodeFromSmali();
+		String code = cls.getCode().toString();
+
+		assertThat(code, containsString("public static void test() {"));
+		assertThat(code, containsOne("return"));
+		assertThat(code, not(containsString("Method dump skipped")));
+	}
+}
diff --git a/jadx-core/src/test/smali/fallback/TestFallbackManyNops.smali b/jadx-core/src/test/smali/fallback/TestFallbackManyNops.smali
new file mode 100644
index 00000000..1c158321
--- /dev/null
+++ b/jadx-core/src/test/smali/fallback/TestFallbackManyNops.smali
@@ -0,0 +1,117 @@
+.class public Lfallback/TestFallbackManyNops;
+.super Ljava/lang/Object;
+
+.method public static test()V
+	.registers 1
+	nop
+	nop
+	nop
+	nop
+	nop
+	nop
+	nop
+	nop
+	nop
+	nop
+	nop
+	nop
+	nop
+	nop
+	nop
+	nop
+	nop
+	nop
+	nop
+	nop
+	nop
+	nop
+	nop
+	nop
+	nop
+	nop
+	nop
+	nop
+	nop
+	nop
+	nop
+	nop
+	nop
+	nop
+	nop
+	nop
+	nop
+	nop
+	nop
+	nop
+	nop
+	nop
+	nop
+	nop
+	nop
+	nop
+	nop
+	nop
+	nop
+	nop
+	nop
+	nop
+	nop
+	nop
+	nop
+	nop
+	nop
+	nop
+	nop
+	nop
+	nop
+	nop
+	nop
+	nop
+	nop
+	nop
+	nop
+	nop
+	nop
+	nop
+	nop
+	nop
+	nop
+	nop
+	nop
+	nop
+	nop
+	nop
+	nop
+	nop
+	nop
+	nop
+	nop
+	nop
+	nop
+	nop
+	nop
+	nop
+	nop
+	nop
+	nop
+	nop
+	nop
+	nop
+	nop
+	nop
+	nop
+	nop
+	nop
+	nop
+	nop
+	nop
+	nop
+	nop
+	nop
+	nop
+	nop
+	nop
+	nop
+	nop
+	return-void
+.end method
-- 
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