Fixed a bug shows in fuzz tests, now all tests pass.
diff --git a/src/dwarf.cc b/src/dwarf.cc
index bfd1f70..6e59ef1 100644
--- a/src/dwarf.cc
+++ b/src/dwarf.cc
@@ -1730,7 +1730,7 @@
     // debug_ranges.
     if (die.ranges && die.ranges->IsUint()) {
       ranges_offset = die.ranges->GetUint(die_reader);
-    } else if (die.start_scope) {
+    } else if (die.start_scope && die.start_scope->IsUint()) {
       ranges_offset = die.start_scope->GetUint(die_reader);
     }