From 569063ca73ce622d77d0af6ee07eaace8e33a6c3 Mon Sep 17 00:00:00 2001
From: Nick Rolfe <nickrolfe@github.com>
Date: Wed, 5 May 2021 17:14:32 +0100
Subject: [PATCH] Make YieldCallTree post-order

---
 .../controlflow/internal/ControlFlowGraphImpl.qll           | 3 +--
 ql/test/library-tests/controlflow/graph/Cfg.expected        | 6 +++---
 2 files changed, 4 insertions(+), 5 deletions(-)

diff --git a/ql/src/codeql_ruby/controlflow/internal/ControlFlowGraphImpl.qll b/ql/src/codeql_ruby/controlflow/internal/ControlFlowGraphImpl.qll
index bd5e91670fd..77664806c7c 100644
--- a/ql/src/codeql_ruby/controlflow/internal/ControlFlowGraphImpl.qll
+++ b/ql/src/codeql_ruby/controlflow/internal/ControlFlowGraphImpl.qll
@@ -1293,8 +1293,7 @@ module Trees {
     }
   }
 
-  // TODO: make post-order
-  private class YieldCallTree extends StandardPreOrderTree, YieldCall {
+  private class YieldCallTree extends StandardPostOrderTree, YieldCall {
     final override ControlFlowTree getChildNode(int i) { result = this.getArgument(i) }
   }
 }
diff --git a/ql/test/library-tests/controlflow/graph/Cfg.expected b/ql/test/library-tests/controlflow/graph/Cfg.expected
index 3e39856c559..025f50e62e4 100644
--- a/ql/test/library-tests/controlflow/graph/Cfg.expected
+++ b/ql/test/library-tests/controlflow/graph/Cfg.expected
@@ -2038,7 +2038,7 @@ cfg.rb:
 #-----|  -> ... != ...
 
 #  190| enter run_block
-#-----|  -> yield ...
+#-----|  -> 42
 
 #  190| run_block
 #-----|  -> self
@@ -2049,10 +2049,10 @@ cfg.rb:
 #-----|  -> exit run_block
 
 #  191| yield ...
-#-----|  -> 42
+#-----|  -> exit run_block (normal)
 
 #  191| 42
-#-----|  -> exit run_block (normal)
+#-----|  -> yield ...
 
 #  194| call to run_block
 #-----|  -> exit cfg.rb (normal)