Fix FP bitwiseOnBoolean (#4280)

Author: chrchr-github

lib/checkbool.cpp

@@ -111,7 +111,7 @@ void CheckBool::checkBitwiseOnBoolean()
                 const bool isBoolOp2 = astIsBool(tok->astOperand2());
                 if (!(isBoolOp1 || isBoolOp2))
                     continue;
-                if (isCompound && !isBoolOp1)
+                if (isCompound && (!isBoolOp1 || isBoolOp2))
                     continue;
                 if (tok->str() == "|" && !isConvertedToBool(tok) && !(isBoolOp1 && isBoolOp2))
                     continue;

test/testbool.cpp

@@ -949,6 +949,12 @@ class TestBool : public TestFixture {
               "    if (b || c) {}\n"
               "}\n");
         ASSERT_EQUALS("", errout.str());
+
+        check("bool f(bool b, int i) {\n"
+              "    b &= (i == 5);\n"
+              "    return b;\n"
+              "}\n");
+        ASSERT_EQUALS("", errout.str());
     }
 
     void incrementBoolean() {