From 783c421a55709c962b9b0fe0246ac5ad1702e783 Mon Sep 17 00:00:00 2001
From: Andrey Vlasovskikh <andrey.vlasovskikh@jetbrains.com>
Date: Mon, 14 Nov 2011 18:15:29 +0400
Subject: [PATCH] Fixed loop-exit CFG edges in for-else loops (PY-4239)

---
 .../controlflow/PyControlFlowBuilder.java        | 16 ++++------------
 python/testData/codeInsight/controlflow/for.py   |  6 +++---
 python/testData/codeInsight/controlflow/for.txt  |  2 +-
 3 files changed, 8 insertions(+), 16 deletions(-)

diff --git a/python/src/com/jetbrains/python/codeInsight/controlflow/PyControlFlowBuilder.java b/python/src/com/jetbrains/python/codeInsight/controlflow/PyControlFlowBuilder.java
index 0a2d76082b37..234f1086d66f 100644
--- a/python/src/com/jetbrains/python/codeInsight/controlflow/PyControlFlowBuilder.java
+++ b/python/src/com/jetbrains/python/codeInsight/controlflow/PyControlFlowBuilder.java
@@ -30,10 +30,6 @@ public class PyControlFlowBuilder extends PyRecursiveElementVisitor {
   private final ControlFlowBuilder myBuilder = new ControlFlowBuilder();
   private List<Pair<PsiElement, Instruction>> myPendindBackup = null;
 
-////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////
-//// Control flow builder staff
-////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////
-
   public ControlFlow buildControlFlow(@NotNull final ScopeOwner owner) {
     return myBuilder.build(this, owner);
   }
@@ -322,27 +318,23 @@ public class PyControlFlowBuilder extends PyRecursiveElementVisitor {
     if (elsePart == null) {
       myBuilder.addPendingEdge(node, myBuilder.prevInstruction);
     }
-
     final PyStatementList list = forPart.getStatementList();
     if (list != null) {
-      Instruction bodyInstruction = myBuilder.startNode(list);
+      final Instruction bodyInstruction = myBuilder.startNode(list);
       final PyExpression target = forPart.getTarget();
       if (target != null) {
         target.accept(this);
       }
-
       list.accept(this);
-
       if (myBuilder.prevInstruction != null) {
         myBuilder.addEdge(myBuilder.prevInstruction, bodyInstruction);  //loop
-        myBuilder.addPendingEdge(node, myBuilder.prevInstruction); // exit
+        myBuilder.addPendingEdge(list, myBuilder.prevInstruction); // exit
       }
-      final Ref<Instruction> bodyInstRef = new Ref<Instruction>(bodyInstruction);
       myBuilder.processPending(new ControlFlowBuilder.PendingProcessor() {
         public void process(final PsiElement pendingScope, final Instruction instruction) {
           if (pendingScope != null && PsiTreeUtil.isAncestor(list, pendingScope, false)) {
-            myBuilder.addEdge(instruction, bodyInstRef.get());  //loop
-            myBuilder.addPendingEdge(node, instruction); // exit
+            myBuilder.addEdge(instruction, bodyInstruction);  //loop
+            myBuilder.addPendingEdge(list, instruction); // exit
           }
           else {
             myBuilder.addPendingEdge(pendingScope, instruction);
diff --git a/python/testData/codeInsight/controlflow/for.py b/python/testData/codeInsight/controlflow/for.py
index 4dd60ddc2fe0..2a3a27c47995 100644
--- a/python/testData/codeInsight/controlflow/for.py
+++ b/python/testData/codeInsight/controlflow/for.py
@@ -1,4 +1,4 @@
-for i in range(10)
+for i in range(10):
     print(i)
-else
-    print "Something went  wrong"
\ No newline at end of file
+else:
+    print('for-loop executed 0 or more times, no break')
\ No newline at end of file
diff --git a/python/testData/codeInsight/controlflow/for.txt b/python/testData/codeInsight/controlflow/for.txt
index bb3183a2ad67..ec5ca7aade0f 100644
--- a/python/testData/codeInsight/controlflow/for.txt
+++ b/python/testData/codeInsight/controlflow/for.txt
@@ -4,6 +4,6 @@
 3(4) element: PyStatementList
 4(5) WRITE ACCESS: i
 5(6) element: PyPrintStatement
-6(3,8) READ ACCESS: i
+6(3,7) READ ACCESS: i
 7(8) element: PyPrintStatement
 8() element: null
\ No newline at end of file