CheckMemoryLeak: Fix fp for allocation function that returns success value

lib/checkmemoryleak.cpp

@@ -464,6 +464,9 @@ const char *CheckMemoryLeak::functionArgAlloc(const Function *func, unsigned int
     if (!func || !func->functionScope)
         return "";
 
+    if (!Token::simpleMatch(func->retDef, "void"))
+        return "";
+
     std::list<Variable>::const_iterator arg = func->argumentList.begin();
     for (; arg != func->argumentList.end(); ++arg) {
         if (arg->index() == targetpar-1)

test/testmemleak.cpp

@@ -2666,6 +2666,20 @@ private:
               "   free(tmp);\n"
               "}");
         ASSERT_EQUALS("", errout.str());
+
+        check("int alloc(char **str) {\n"
+              "   *str = malloc(20);\n"
+              "   if (condition) { free(str); return -123; }\n"
+              "   return 0;\n"
+              "}\n"
+              "\n"
+              "void bar()\n"
+              "{\n"
+              "   char *p;\n"
+              "   if ((ret = alloc(&p)) != 0) return;\n"
+              "   free(p);\n"
+              "}");
+        ASSERT_EQUALS(std::string(""), errout.str());
     }