assignmentInCondition: Clarify error message

lib/checkcondition.cpp

@@ -1716,6 +1716,8 @@ void CheckCondition::checkAssignmentInCondition()
             // Is this assignment of container/iterator?
             if (!tok->valueType())
                 continue;
+            if (tok->valueType()->pointer > 0)
+                continue;
             if (tok->valueType()->type != ValueType::Type::CONTAINER && tok->valueType()->type != ValueType::Type::ITERATOR)
                 continue;
 
@@ -1732,11 +1734,13 @@ void CheckCondition::checkAssignmentInCondition()
 
 void CheckCondition::assignmentInCondition(const Token *eq)
 {
+    std::string expr = eq ? eq->expressionString() : "x=y";
+
     reportError(
         eq,
         Severity::style,
         "assignmentInCondition",
-        "Assignment in condition should probably be comparison.",
+        "Suspicious assignment in condition. Condition '" + expr + "' is always true.",
         CWE571,
         Certainty::normal);
 }

lib/checkcondition.h

@@ -211,7 +211,7 @@ private:
                "- Comparisons of modulo results that are always true/false.\n"
                "- Known variable values => condition is always true/false\n"
                "- Invalid test for overflow. Some mainstream compilers remove such overflow tests when optimising code.\n"
-               "- Assignment of container/iterator in condition should probably be comparison.\n";
+               "- Suspicious assignment of container/iterator in condition => condition is always true.\n";
     }
 };
 /// @}

test/testcondition.cpp

@@ -4160,7 +4160,12 @@ private:
         check("void f(std::string s) {\n"
               "    if (s=\"123\"){}\n"
               "}");
-        ASSERT_EQUALS("[test.cpp:2]: (style) Assignment in condition should probably be comparison.\n", errout.str());
+        ASSERT_EQUALS("[test.cpp:2]: (style) Suspicious assignment in condition. Condition 's=\"123\"' is always true.\n", errout.str());
+
+        check("void f(std::string *p) {\n"
+              "    if (p=foo()){}\n"
+              "}");
+        ASSERT_EQUALS("", errout.str());
     }
 };