From 05ec42064388689a256dd31304001908575ca02a Mon Sep 17 00:00:00 2001
From: Dmitry Jemerov <yole@jetbrains.com>
Date: Tue, 5 Jul 2011 15:02:52 +0200
Subject: [PATCH] fixed a case when formatter breaks code (PY-4034 comment)

---
 python/src/com/jetbrains/python/formatter/PyBlock.java   | 5 +++--
 python/testData/formatter/tupleAssignment.py             | 8 ++++++++
 python/testData/formatter/tupleAssignment_after.py       | 8 ++++++++
 python/testSrc/com/jetbrains/python/PyFormatterTest.java | 4 ++++
 4 files changed, 23 insertions(+), 2 deletions(-)
 create mode 100644 python/testData/formatter/tupleAssignment.py
 create mode 100644 python/testData/formatter/tupleAssignment_after.py

diff --git a/python/src/com/jetbrains/python/formatter/PyBlock.java b/python/src/com/jetbrains/python/formatter/PyBlock.java
index 40169cac6b31..2b03588bd7b4 100644
--- a/python/src/com/jetbrains/python/formatter/PyBlock.java
+++ b/python/src/com/jetbrains/python/formatter/PyBlock.java
@@ -177,7 +177,7 @@ public class PyBlock implements ASTBlock {
         childIndent = Indent.getNormalIndent();
       }
     }
-    else if (parentType == PyElementTypes.PARENTHESIZED_EXPRESSION) {
+    else if (parentType == PyElementTypes.PARENTHESIZED_EXPRESSION && hasLineBreaksBefore(child, 1)) {
       childIndent = Indent.getNormalIndent();
     }
 
@@ -242,7 +242,8 @@ public class PyBlock implements ASTBlock {
   }
 
   private static boolean hasLineBreaksBefore(ASTNode child, int minCount) {
-    return isWhitespaceWithLineBreaks(TreeUtil.findLastLeaf(child.getTreePrev()), minCount) ||
+    final ASTNode treePrev = child.getTreePrev();
+    return (treePrev != null && isWhitespaceWithLineBreaks(TreeUtil.findLastLeaf(treePrev), minCount)) ||
            isWhitespaceWithLineBreaks(child.getFirstChildNode(), minCount);
   }
 
diff --git a/python/testData/formatter/tupleAssignment.py b/python/testData/formatter/tupleAssignment.py
new file mode 100644
index 000000000000..3218dc78e424
--- /dev/null
+++ b/python/testData/formatter/tupleAssignment.py
@@ -0,0 +1,8 @@
+def bad_autoformat_example():
+    a = 5
+    b = 10
+    print a, b
+    (a, b) = b, a
+    print a, b
+    a, b = b, a
+    print a, b
\ No newline at end of file
diff --git a/python/testData/formatter/tupleAssignment_after.py b/python/testData/formatter/tupleAssignment_after.py
new file mode 100644
index 000000000000..3218dc78e424
--- /dev/null
+++ b/python/testData/formatter/tupleAssignment_after.py
@@ -0,0 +1,8 @@
+def bad_autoformat_example():
+    a = 5
+    b = 10
+    print a, b
+    (a, b) = b, a
+    print a, b
+    a, b = b, a
+    print a, b
\ No newline at end of file
diff --git a/python/testSrc/com/jetbrains/python/PyFormatterTest.java b/python/testSrc/com/jetbrains/python/PyFormatterTest.java
index 80e4413d11cd..3bb0f3af12ed 100644
--- a/python/testSrc/com/jetbrains/python/PyFormatterTest.java
+++ b/python/testSrc/com/jetbrains/python/PyFormatterTest.java
@@ -113,6 +113,10 @@ public class PyFormatterTest extends PyLightFixtureTestCase {
     doTest();
   }
 
+  public void testTupleAssignment() {  // PY-4034 comment
+    doTest();
+  }
+
   public void testPsiFormatting() { // IDEA-69724
     String initial =
       "def method_name(\n" +