Fixed IllegalArgumentException in OpcodeStack.constantToInt

This fixes issue #893

Signed-off-by: Andrey Loskutov <loskutov@gmx.de>

CHANGELOG.md

@@ -8,6 +8,7 @@ Currently the versioning policy of this project follows [Semantic Versioning v2.
 ### Changed
 * Bump jaxen from 1.1.6 to 1.2.0 supporting Java 11 compilation ([#1316](https://github.com/spotbugs/spotbugs/issues/1316))
 * Fixed error dialog on cancelling SpotBugs job in Eclipse ([#1314](https://github.com/spotbugs/spotbugs/issues/1314))
+* Fixed IllegalArgumentException in OpcodeStack.constantToInt ([#893](https://github.com/spotbugs/spotbugs/issues/893))
 * Bump ASM from 8.0.1 to 9.0 supporting JDK16 (sealed classes)
 
 ## 4.1.3 - 2020-09-25

spotbugs-tests/src/test/java/edu/umd/cs/findbugs/ba/Issue893Test.java

@@ -0,0 +1,21 @@
+package edu.umd.cs.findbugs.ba;
+
+import static edu.umd.cs.findbugs.test.CountMatcher.containsExactly;
+import static org.hamcrest.MatcherAssert.assertThat;
+
+import org.junit.Test;
+
+import edu.umd.cs.findbugs.AbstractIntegrationTest;
+import edu.umd.cs.findbugs.test.matcher.BugInstanceMatcher;
+import edu.umd.cs.findbugs.test.matcher.BugInstanceMatcherBuilder;
+
+public class Issue893Test extends AbstractIntegrationTest {
+
+    @Test
+    public void test() {
+        performAnalysis("ghIssues/Issue893.class");
+        BugInstanceMatcher bugTypeMatcher = new BugInstanceMatcherBuilder().build();
+        assertThat(getBugCollection(), containsExactly(0, bugTypeMatcher));
+    }
+
+}

spotbugs/src/main/java/edu/umd/cs/findbugs/OpcodeStack.java

@@ -2194,6 +2194,10 @@ private int constantToInt(Item it) {
         if (constant instanceof Character) {
             return ((Character) constant).charValue();
         }
+        if (constant instanceof Boolean) {
+            Boolean val = (Boolean) constant;
+            return val.booleanValue() ? 1 : 0;
+        }
         throw new IllegalArgumentException(String.valueOf(constant));
     }
 

spotbugsTestCases/src/java/ghIssues/Issue893.java

@@ -0,0 +1,10 @@
+package ghIssues;
+
+public class Issue893 {
+    public boolean test() throws Exception {
+        Boolean b = Boolean.valueOf(true);
+        // Line below should not throw IllegalArgumentException during analysis
+        b &= Boolean.valueOf(false);
+        return b;
+    }
+}