Fixed #1041 (passing a nullpointer to a reference)

lib/checkother.cpp

@@ -1275,6 +1275,19 @@ private:
                 bailOutVar(checks, tok.varId());
         }
 
+        if (Token::simpleMatch(&tok, "* 0"))
+        {
+            if (Token::Match(tok.previous(), "[;{}=]"))
+            {
+                CheckOther *checkOther = dynamic_cast<CheckOther *>(owner);
+                if (checkOther)
+                {
+                    checkOther->nullPointerError(&tok);
+                    foundError = true;
+                }
+            }
+        }
+
         return &tok;
     }
 
@@ -1867,6 +1880,11 @@ void CheckOther::strPlusChar(const Token *tok)
     reportError(tok, Severity::error, "strPlusChar", "Unusual pointer arithmetic");
 }
 
+void CheckOther::nullPointerError(const Token *tok)
+{
+    reportError(tok, Severity::error, "nullPointer", "Null pointer dereference");
+}
+
 void CheckOther::nullPointerError(const Token *tok, const std::string &varname)
 {
     reportError(tok, Severity::error, "nullPointer", "Possible null pointer dereference: " + varname);

lib/checkother.h

@@ -147,6 +147,7 @@ public:
     void variableScopeError(const Token *tok, const std::string &varname);
     void conditionAlwaysTrueFalse(const Token *tok, const std::string &truefalse);
     void strPlusChar(const Token *tok);
+    void nullPointerError(const Token *tok);  // variable name unknown / doesn't exist
     void nullPointerError(const Token *tok, const std::string &varname);
     void nullPointerError(const Token *tok, const std::string &varname, const int line);
     void uninitdataError(const Token *tok, const std::string &varname);

test/testother.cpp

@@ -915,6 +915,13 @@ private:
                          "}\n");
         ASSERT_EQUALS("[test.cpp:5]: (error) Possible null pointer dereference: q\n", errout.str());
 
+        checkNullPointer("static void foo()\n"
+                         "{\n"
+                         "    int *p = 0;\n"
+                         "    int &r = *p;\n"
+                         "}\n");
+        ASSERT_EQUALS("[test.cpp:4]: (error) Null pointer dereference\n", errout.str());
+
         // no false positive..
         checkNullPointer("static void foo()\n"
                          "{\n"