Fix #10426 FN (style) Condition 's.empty()' is always false (#4414)

* Fix #10426 FN (style) Condition 's.empty()' is always false

* Fix test

Author: chrchr-github

lib/checkcondition.cpp

@@ -1516,7 +1516,7 @@ void CheckCondition::alwaysTrueFalse()
                 tok->astParent() && Token::Match(tok->astTop()->astOperand1(), "if|while") && !tok->astTop()->astOperand1()->isConstexpr() &&
                 (Token::Match(tok->astParent(), "%oror%|&&") || Token::Match(tok->astParent()->astOperand1(), "if|while"));
             const bool constValExpr = tok->isNumber() && Token::Match(tok->astParent(),"%oror%|&&|?"); // just one number in boolean expression
-            const bool compExpr = Token::Match(tok, "%comp%|!"); // a compare expression
+            const bool compExpr = Token::Match(tok, "%comp%|!|("); // a compare expression
             const bool ternaryExpression = Token::simpleMatch(tok->astParent(), "?");
             const bool returnExpression = Token::simpleMatch(tok->astTop(), "return") && (tok->isComparisonOp() || Token::Match(tok, "&&|%oror%"));
 

test/cfg/qt.cpp

@@ -32,7 +32,7 @@ void QString1(QString s)
 int QString2()
 {
     QString s;
-    // FIXME cppcheck-suppress reademptycontainer
+    // cppcheck-suppress knownConditionTrueFalse
     return s.size();
 }
 

test/testcondition.cpp

@@ -4305,6 +4305,18 @@ class TestCondition : public TestFixture {
               "    else if (x < 1) {}\n"
               "}\n");
         ASSERT_EQUALS("", errout.str());
+
+        // #10426
+        check("void f() {\n"
+              "    std::string s;\n"
+              "    for (; !s.empty();) {}\n"
+              "    for (; s.empty();) {}\n"
+              "    if (s.empty()) {}\n"
+              "}\n");
+        ASSERT_EQUALS("[test.cpp:3]: (style) Condition '!s.empty()' is always false\n"
+                      "[test.cpp:4]: (style) Condition 's.empty()' is always true\n"
+                      "[test.cpp:5]: (style) Condition 's.empty()' is always true\n",
+                      errout.str());
     }
 
     void alwaysTrueSymbolic()