upd cherry0pick

Author: aschackmull

ruby/ql/lib/codeql/ruby/dataflow/internal/DataFlowPrivate.qll

@@ -1658,6 +1658,19 @@ private module ReturnNodes {
     result = n
   }
 
+  private Expr getLast(StmtSequence s) {
+    result = getLast(s.(BodyStmt).getElse())
+    or
+    result = getLast(s.(BodyStmt).getARescue().getBody())
+    or
+    not exists(s.(BodyStmt).getElse()) and
+    exists(Stmt last | last = s.getLastStmt() |
+      result = getLast(last)
+      or
+      result = last and not last instanceof StmtSequence
+    )
+  }
+
   /**
    * A data-flow node that represents an expression implicitly returned by
    * a callable. An implicit return happens when an expression can be the
@@ -1666,7 +1679,7 @@ private module ReturnNodes {
   class ExprReturnNode extends SourceReturnNode, ExprNode {
     ExprReturnNode() {
       // exists(Callable c | implicitReturn(c, this) = c.getBody().getAStmt())
-      this.getExprNode().getExpr() = desugar(any(Callable c).getBody().getLastStmt())
+      this.getExprNode().getExpr() = desugar(getLast(any(Callable c).getBody()))
     }
 
     override ReturnKind getKindSource() {