diff --git a/lib/checkother.cpp b/lib/checkother.cpp
index cb6813c86..33eba962b 100644
--- a/lib/checkother.cpp
+++ b/lib/checkother.cpp
@@ -1435,7 +1435,7 @@ bool CheckOther::checkInnerScope(const Token *tok, const Variable* var, bool& us
     }
 
     bool bFirstAssignment=false;
-    for (; tok != end; tok = tok->next()) {
+    for (; tok && tok != end; tok = tok->next()) {
         if (tok->str() == "goto")
             return false;
         if (tok->str() == "continue")
diff --git a/test/testgarbage.cpp b/test/testgarbage.cpp
index bd7bf9cd0..ca2e23cf8 100644
--- a/test/testgarbage.cpp
+++ b/test/testgarbage.cpp
@@ -122,6 +122,7 @@ private:
         TEST_CASE(garbageCode81);
         TEST_CASE(garbageCode82);
         TEST_CASE(garbageCode83);
+        TEST_CASE(garbageCode84);
 
         TEST_CASE(garbageValueFlow);
         TEST_CASE(garbageSymbolDatabase);
@@ -676,6 +677,10 @@ private:
         ASSERT_THROW(checkCode("namespace A { class } class A { friend C ; } { } ;"), InternalError);
     }
 
+    void garbageCode84() { // #6780
+        checkCode("int main ( [ ] ) { " " [ ] ; int i = 0 ; do { } ; } ( [ ] ) { }"); // do not crash
+    }
+
     void garbageValueFlow() {
         // #6089
         const char* code = "{} int foo(struct, x1, struct x2, x3, int, x5, x6, x7)\n"