simplify graph

graphs/dfg.ql

@@ -21,10 +21,12 @@ query predicate nodes(DataFlow::Node n1, string key, string value) {
 }
 
 query predicate edges(DataFlow::Node n1, DataFlow::Node n2) {
-  exists(Function f1 |
-    f1.hasName("copy_mem") and
-    n1.getFunction() = f1 and
+  //  Find all nodes that flow into the conditional expression of an if-statement.
+  exists(ConditionalStmt cond, DataFlow::Node n3 |
+    cond.getControllingExpr().getAChild() = n3.asExpr() and
+    DataFlow::localFlow(n1, n3) and
     DataFlow::localFlowStep(n1, n2) and
+    n1 != n2 and
     n2.getLocation().getStartLine() < 46
   )
 }