diff --git a/lib/checkpostfixoperator.cpp b/lib/checkpostfixoperator.cpp
index 7294e688d..4e7851457 100644
--- a/lib/checkpostfixoperator.cpp
+++ b/lib/checkpostfixoperator.cpp
@@ -55,7 +55,7 @@ void CheckPostfixOperator::postfixOperator()
             else if (tok->strAt(-2) == ",")
             {
                 int i(1);
-                while (tok->strAt(i) != ")")
+                while (tok->strAt(i) != ")" && tok->tokAt(i) != 0)
                 {
                     if (tok->strAt(i) == ";")
                     {
diff --git a/test/testpostfixoperator.cpp b/test/testpostfixoperator.cpp
index b789d977e..d3955ca85 100644
--- a/test/testpostfixoperator.cpp
+++ b/test/testpostfixoperator.cpp
@@ -70,6 +70,13 @@ private:
         TEST_CASE(testiterator);
         TEST_CASE(test2168);
         TEST_CASE(pointer);   // #2321 - postincrement of pointer is OK
+        TEST_CASE(testHangWithInvalidCode); // #2847 - cppcheck hangs with 100% cpu load
+    }
+
+    void testHangWithInvalidCode()
+    {
+        check("a,b--\n");
+        ASSERT_EQUALS("", errout.str());
     }
 
     void testsimple()