STL: added testcase for 'if (str.find(%any%)) ..'

lib/checkstl.cpp

@@ -553,6 +553,8 @@ void CheckStl::if_find()
                 // stl container
                 if (Token::Match(decl, "const| std :: %var% < %type% > &|*| %varid%", varid))
                     if_findError(tok, false);
+                else if (Token::Match(decl, "const| std :: string &|*| %varid%", varid))
+                    if_findError(tok, true);
             }
         }
 
@@ -576,7 +578,7 @@ void CheckStl::if_find()
 void CheckStl::if_findError(const Token *tok, bool str)
 {
     if (str)
-        reportError(tok, Severity::possibleStyle, "stlIfStrFind", "Suspicious condition. string::find will return 0 if the string is found at position 0. If this is what you want to check then string::compare is a faster alternative because it doesn't scan through the string.");
+        reportError(tok, Severity::style, "stlIfStrFind", "Suspicious condition. string::find will return 0 if the string is found at position 0. If this is what you want to check then string::compare is a faster alternative because it doesn't scan through the string.");
     else
         reportError(tok, Severity::style, "stlIfFind", "Suspicious condition. The result of find is an iterator, but it is not properly checked.");
 }

test/teststl.cpp

@@ -76,6 +76,7 @@ private:
 
         // if (str.find("ab"))
         TEST_CASE(if_find);
+        TEST_CASE(if_str_find);
 
         TEST_CASE(size1);
     }
@@ -736,7 +737,15 @@ private:
         ASSERT_EQUALS("", errout.str());
     }
 
-
+    void if_str_find()
+    {
+        // error
+        check("void f(const std::string &s)\n"
+              "{\n"
+              "    if (s.find(\"abc\")) { }\n"
+              "}\n");
+        ASSERT_EQUALS("[test.cpp:3]: (style) Suspicious condition. string::find will return 0 if the string is found at position 0. If this is what you want to check then string::compare is a faster alternative because it doesn't scan through the string.\n", errout.str());
+    }
 
 
     void size1()