Fix #771 (False positive. Null pointer dereference in a switch case)

http://sourceforge.net/apps/trac/cppcheck/ticket/771

src/checkother.cpp

@@ -866,7 +866,7 @@ void CheckOther::nullPointer()
         // Check if the variable is dereferenced..
         while (tok2)
         {
-            if (tok2->str() == "{" || tok2->str() == "}")
+            if (tok2->str() == "{" || tok2->str() == "}" || tok2->str() == "break")
                 break;
 
             if (tok2->varId() == varid)

test/testother.cpp

@@ -628,6 +628,21 @@ private:
                          "    }\n"
                          "}\n");
         ASSERT_EQUALS("", errout.str());
+
+        checkNullPointer("void foo(A*a)\n"
+                         "{\n"
+                         "  switch (a->b()) {\n"
+                         "    case 1:\n"
+                         "      while( a ){\n"
+                         "        a = a->next;\n"
+                         "      }\n"
+                         "    break;\n"
+                         "    case 2:\n"
+                         "      a->b();\n"
+                         "      break;\n"
+                         "  }\n"
+                         "}\n");
+        ASSERT_EQUALS("", errout.str());
     }
 
     void nullpointer2()