Fix issue 9718: False positive: Parameter can be declared const when written to via stream extraction operator (#2677)

Author: pfultz2

lib/astutils.cpp

@@ -1578,7 +1578,7 @@ bool isLikelyStreamRead(bool cpp, const Token *op)
     const Token *parent = op;
     while (parent->astParent() && parent->astParent()->str() == op->str())
         parent = parent->astParent();
-    if (parent->astParent() && !Token::Match(parent->astParent(), "%oror%|&&|(|,|!"))
+    if (parent->astParent() && !Token::Match(parent->astParent(), "%oror%|&&|(|,|.|!"))
         return false;
     if (op->str() == "&" && parent->astParent())
         return false;

test/testother.cpp

@@ -1977,6 +1977,12 @@ class TestOther : public TestFixture {
               "}\n");
         ASSERT_EQUALS("", errout.str());
 
+        check("bool from_string(int& t, const std::string& s) {\n"
+              "    std::istringstream iss(s);\n"
+              "    return !(iss >> t).fail();\n"
+              "}\n");
+        ASSERT_EQUALS("", errout.str());
+
         check("void e();\n"
               "void g(void);\n"
               "void h(void);\n"