Fixed #4426 (False positive: Unitialized variable warning when comparing addresses)

lib/checkuninitvar.cpp

@@ -1417,6 +1417,8 @@ bool CheckUninitVar::isVariableUsage(const Scope* scope, const Token *vartok, bo
         // is there something like: ; "*((&var ..expr.. ="  => the variable is assigned
         if (vartok->previous()->str() == "&") {
             const Token *tok2 = vartok->tokAt(-2);
+            if (tok2 && (tok2->isOp() || tok2->str() == "("))
+                return false; // address of
             if (Token::simpleMatch(tok2,")"))
                 tok2 = tok2->link()->previous();
             while (tok2 && tok2->str() == "(")

test/testuninitvar.cpp

@@ -2321,6 +2321,13 @@ private:
                         "    return x;\n"
                         "}\n");
         ASSERT_EQUALS("", errout.str());
+
+        // &
+        checkUninitVar2("void f() {\n"  // #4426 - address of uninitialized variable
+                        "    int a,b;\n"
+                        "    if (&a == &b);\n"
+                        "}");
+        ASSERT_EQUALS("", errout.str());
     }
 
     // #3869 - reference variable