Fix 11295: Regression FP: knownConditionTrueFalse (#4443)

Author: pfultz2

lib/checkcondition.cpp

@@ -1494,7 +1494,9 @@ void CheckCondition::alwaysTrueFalse()
                 continue;
             if (!isUsedAsBool(tok))
                 continue;
-            if (Token::simpleMatch(tok->astParent(), "return") && Token::Match(tok, ".|%var%|%assign%"))
+            if (Token::simpleMatch(condition, "return") && Token::Match(tok, "%assign%"))
+                continue;
+            if (Token::simpleMatch(tok->astParent(), "return") && Token::Match(tok, ".|%var%"))
                 continue;
             if (Token::Match(tok, "%num%|%bool%|%char%"))
                 continue;

test/testcondition.cpp

@@ -4341,6 +4341,13 @@ class TestCondition : public TestFixture {
         ASSERT_EQUALS("[test.cpp:3]: (style) Condition 'f()' is always true\n"
                       "[test.cpp:4]: (style) Condition 'f()==3' is always true\n",
                       errout.str());
+
+        check("int f() {\n"
+              "    const char *n;\n"
+              "    return((n=42) &&\n"
+              "           *n == 'A');\n"
+              "}\n");
+        ASSERT_EQUALS("", errout.str());
     }
 
     void alwaysTrueSymbolic()