now we intersect only reachable fathers' dominators

slither/core/dominators/utils.py

@@ -9,11 +9,17 @@ if TYPE_CHECKING:
 def intersection_predecessor(node: "Node") -> Set["Node"]:
     if not node.fathers:
         return set()
-    ret = node.fathers[0].dominators
-    for pred in node.fathers[1:]:
-        ret = ret.intersection(pred.dominators)
-    return ret
+    if not any(father.is_reachable for father in node.fathers):
+        return set()
 
+    ret = set()
+    for pred in node.fathers:
+        ret = ret.union(pred.dominators)
+
+    for pred in node.fathers:
+        if pred.is_reachable:
+            ret = ret.intersection(pred.dominators)
+    return ret
 
 def _compute_dominators(nodes: List["Node"]) -> None:
     changed = True
@@ -84,6 +90,8 @@ def compute_dominance_frontier(nodes: List["Node"]) -> None:
     for node in nodes:
         if len(node.fathers) >= 2:
             for father in node.fathers:
+                if not father.is_reachable:
+                    continue
                 runner = father
                 # Corner case: if there is a if without else
                 # we need to add update the conditional node